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Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. Someone give a strange birthday present to Ivan. It is hedgehog — connected undirected graph in which one vertex has degree at least 3 (we will call it center) and all other vertices has degree 1. Ivan thought that hedgehog is too boring and decided to make himself k-multihedgehog. Let us define k-multihedgehog as follows: * 1-multihedgehog is hedgehog: it has one vertex of degree at least 3 and some vertices of degree 1. * For all k ≥ 2, k-multihedgehog is (k-1)-multihedgehog in which the following changes has been made for each vertex v with degree 1: let u be its only neighbor; remove vertex v, create a new hedgehog with center at vertex w and connect vertices u and w with an edge. New hedgehogs can differ from each other and the initial gift. Thereby k-multihedgehog is a tree. Ivan made k-multihedgehog but he is not sure that he did not make any mistakes. That is why he asked you to check if his tree is indeed k-multihedgehog. Input First line of input contains 2 integers n, k (1 ≤ n ≤ 10^{5}, 1 ≤ k ≤ 10^{9}) — number of vertices and hedgehog parameter. Next n-1 lines contains two integers u v (1 ≤ u, v ≤ n; u ≠ v) — indices of vertices connected by edge. It is guaranteed that given graph is a tree. Output Print "Yes" (without quotes), if given graph is k-multihedgehog, and "No" (without quotes) otherwise. Examples Input 14 2 1 4 2 4 3 4 4 13 10 5 11 5 12 5 14 5 5 13 6 7 8 6 13 6 9 6 Output Yes Input 3 1 1 3 2 3 Output No Note 2-multihedgehog from the first example looks like this: <image> Its center is vertex 13. Hedgehogs created on last step are: [4 (center), 1, 2, 3], [6 (center), 7, 8, 9], [5 (center), 10, 11, 12, 13]. Tree from second example is not a hedgehog because degree of center should be at least 3. Submitted Solution: ``` from collections import deque m, k = list(map(int, input().split())) G = [set() for _ in range(m + 1)] q, nq = deque(), deque() for _ in range(m - 1): u, v = list(map(int, input().split())) G[u].add(v) G[v].add(u) for u in range(1, m + 1): if len(G[u]) == 1: q.append(u) step = 0 removed = 0 ok = True while removed < m - 1: each = {} for u in q: nxt = G[u].pop() G[nxt].remove(u) each[nxt] = each.get(nxt, 0) + 1 removed += 1 if len(G[nxt]) == 0: break if len(G[nxt]) == 1: nq.append(nxt) if any(v < 3 for k,v in each.items()): ok = False break q, nq = nq, deque() step += 1 if ok and step == k and removed == m - 1: print('Yes') else: print('No') ```
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Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. Someone give a strange birthday present to Ivan. It is hedgehog — connected undirected graph in which one vertex has degree at least 3 (we will call it center) and all other vertices has degree 1. Ivan thought that hedgehog is too boring and decided to make himself k-multihedgehog. Let us define k-multihedgehog as follows: * 1-multihedgehog is hedgehog: it has one vertex of degree at least 3 and some vertices of degree 1. * For all k ≥ 2, k-multihedgehog is (k-1)-multihedgehog in which the following changes has been made for each vertex v with degree 1: let u be its only neighbor; remove vertex v, create a new hedgehog with center at vertex w and connect vertices u and w with an edge. New hedgehogs can differ from each other and the initial gift. Thereby k-multihedgehog is a tree. Ivan made k-multihedgehog but he is not sure that he did not make any mistakes. That is why he asked you to check if his tree is indeed k-multihedgehog. Input First line of input contains 2 integers n, k (1 ≤ n ≤ 10^{5}, 1 ≤ k ≤ 10^{9}) — number of vertices and hedgehog parameter. Next n-1 lines contains two integers u v (1 ≤ u, v ≤ n; u ≠ v) — indices of vertices connected by edge. It is guaranteed that given graph is a tree. Output Print "Yes" (without quotes), if given graph is k-multihedgehog, and "No" (without quotes) otherwise. Examples Input 14 2 1 4 2 4 3 4 4 13 10 5 11 5 12 5 14 5 5 13 6 7 8 6 13 6 9 6 Output Yes Input 3 1 1 3 2 3 Output No Note 2-multihedgehog from the first example looks like this: <image> Its center is vertex 13. Hedgehogs created on last step are: [4 (center), 1, 2, 3], [6 (center), 7, 8, 9], [5 (center), 10, 11, 12, 13]. Tree from second example is not a hedgehog because degree of center should be at least 3. Submitted Solution: ``` from sys import stdin from collections import deque n, k = map(int, stdin.readline().split()) graph = [[] for _ in range(n)] leaf = -1 for _ in range(n-1): a,b = map(int,stdin.readline().split()) graph[a - 1].append(b - 1) graph[b - 1].append(a - 1) def bfs(G, s): # la cola comienza con el vertice desde el cual hacemos bfs Q = deque() Q.append(s) # al inicio todas las distancias comienzan en infinito, por las # restricciones del problema ningun camino va a ser de ese tamanno infinite = 10 ** 6 d = [infinite]*n parent = [-1]*n valid = True # la distancia del vertice raiz es 0 d[s] = 0 while Q: # visitamos u u = Q.popleft() not_visited_count = 0 # visitamos cada adyacente de u for v in G[u]: # si no lo hemos visitado, le ponemos distancia y # lo agregamos a la cola para visitar sus adyacentes if d[v] == infinite: d[v] = d[u] + 1 parent[v] = u Q.append(v) not_visited_count += 1 if not_visited_count < 3 and d[u] != k: valid = False # retornamos el array d, que es el de las distancias del # nodo s al resto de los nodos del grafo return d, parent, valid leaf = -1 for i,v in enumerate(graph): if len(v) == 1: leaf = i break d, parent, _ = bfs(graph,leaf) center = -1 farthest_leaf = -1 diameter = 2*k for i,level in enumerate(d): if level == diameter: farthest_leaf = i break if len(graph[farthest_leaf]) != 1 or farthest_leaf == -1: print("NO") exit() for _ in range(k): center = parent[farthest_leaf] farthest_leaf = center if center == -1: print("NO") exit() _, _, valid = bfs(graph,center) if valid: print("YES") else: print("NO") ```
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Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. Someone give a strange birthday present to Ivan. It is hedgehog — connected undirected graph in which one vertex has degree at least 3 (we will call it center) and all other vertices has degree 1. Ivan thought that hedgehog is too boring and decided to make himself k-multihedgehog. Let us define k-multihedgehog as follows: * 1-multihedgehog is hedgehog: it has one vertex of degree at least 3 and some vertices of degree 1. * For all k ≥ 2, k-multihedgehog is (k-1)-multihedgehog in which the following changes has been made for each vertex v with degree 1: let u be its only neighbor; remove vertex v, create a new hedgehog with center at vertex w and connect vertices u and w with an edge. New hedgehogs can differ from each other and the initial gift. Thereby k-multihedgehog is a tree. Ivan made k-multihedgehog but he is not sure that he did not make any mistakes. That is why he asked you to check if his tree is indeed k-multihedgehog. Input First line of input contains 2 integers n, k (1 ≤ n ≤ 10^{5}, 1 ≤ k ≤ 10^{9}) — number of vertices and hedgehog parameter. Next n-1 lines contains two integers u v (1 ≤ u, v ≤ n; u ≠ v) — indices of vertices connected by edge. It is guaranteed that given graph is a tree. Output Print "Yes" (without quotes), if given graph is k-multihedgehog, and "No" (without quotes) otherwise. Examples Input 14 2 1 4 2 4 3 4 4 13 10 5 11 5 12 5 14 5 5 13 6 7 8 6 13 6 9 6 Output Yes Input 3 1 1 3 2 3 Output No Note 2-multihedgehog from the first example looks like this: <image> Its center is vertex 13. Hedgehogs created on last step are: [4 (center), 1, 2, 3], [6 (center), 7, 8, 9], [5 (center), 10, 11, 12, 13]. Tree from second example is not a hedgehog because degree of center should be at least 3. Submitted Solution: ``` WQ=input().split() n1=int(WQ[0]) k=int(WQ[1]) L1=[] for i in range(n1): L1.append([]) for i in range(n1-1): X=input().split() x1=int(X[0])-1 x2=int(X[1])-1 L1[x1].append(x2) L1[x2].append(x1) t=True tres=0 for i in range(n1): l=len(L1[i]) if l==1: pass elif l==3: tres+=1 elif l>3: pass else: t=False break if t: if tres>1: print("No") else: print("Yes") else: print("No") ```
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Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. Someone give a strange birthday present to Ivan. It is hedgehog — connected undirected graph in which one vertex has degree at least 3 (we will call it center) and all other vertices has degree 1. Ivan thought that hedgehog is too boring and decided to make himself k-multihedgehog. Let us define k-multihedgehog as follows: * 1-multihedgehog is hedgehog: it has one vertex of degree at least 3 and some vertices of degree 1. * For all k ≥ 2, k-multihedgehog is (k-1)-multihedgehog in which the following changes has been made for each vertex v with degree 1: let u be its only neighbor; remove vertex v, create a new hedgehog with center at vertex w and connect vertices u and w with an edge. New hedgehogs can differ from each other and the initial gift. Thereby k-multihedgehog is a tree. Ivan made k-multihedgehog but he is not sure that he did not make any mistakes. That is why he asked you to check if his tree is indeed k-multihedgehog. Input First line of input contains 2 integers n, k (1 ≤ n ≤ 10^{5}, 1 ≤ k ≤ 10^{9}) — number of vertices and hedgehog parameter. Next n-1 lines contains two integers u v (1 ≤ u, v ≤ n; u ≠ v) — indices of vertices connected by edge. It is guaranteed that given graph is a tree. Output Print "Yes" (without quotes), if given graph is k-multihedgehog, and "No" (without quotes) otherwise. Examples Input 14 2 1 4 2 4 3 4 4 13 10 5 11 5 12 5 14 5 5 13 6 7 8 6 13 6 9 6 Output Yes Input 3 1 1 3 2 3 Output No Note 2-multihedgehog from the first example looks like this: <image> Its center is vertex 13. Hedgehogs created on last step are: [4 (center), 1, 2, 3], [6 (center), 7, 8, 9], [5 (center), 10, 11, 12, 13]. Tree from second example is not a hedgehog because degree of center should be at least 3. Submitted Solution: ``` WQ=input().split() n1=int(WQ[0]) k=int(WQ[1]) L1=[] for i in range(n1): L1.append([]) for i in range(n1-1): X=input().split() x1=int(X[0])-1 x2=int(X[1])-1 L1[x1].append(x2) L1[x2].append(x1) t=True tres=0 for i in range(n1): l=len(L1[i]) if l==1: pass elif l==3: tres+=1 elif l>3: pass else: t=False if t: if tres>1: print("No") else: print("Yes") else: print("No") ```
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Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. Someone give a strange birthday present to Ivan. It is hedgehog — connected undirected graph in which one vertex has degree at least 3 (we will call it center) and all other vertices has degree 1. Ivan thought that hedgehog is too boring and decided to make himself k-multihedgehog. Let us define k-multihedgehog as follows: * 1-multihedgehog is hedgehog: it has one vertex of degree at least 3 and some vertices of degree 1. * For all k ≥ 2, k-multihedgehog is (k-1)-multihedgehog in which the following changes has been made for each vertex v with degree 1: let u be its only neighbor; remove vertex v, create a new hedgehog with center at vertex w and connect vertices u and w with an edge. New hedgehogs can differ from each other and the initial gift. Thereby k-multihedgehog is a tree. Ivan made k-multihedgehog but he is not sure that he did not make any mistakes. That is why he asked you to check if his tree is indeed k-multihedgehog. Input First line of input contains 2 integers n, k (1 ≤ n ≤ 10^{5}, 1 ≤ k ≤ 10^{9}) — number of vertices and hedgehog parameter. Next n-1 lines contains two integers u v (1 ≤ u, v ≤ n; u ≠ v) — indices of vertices connected by edge. It is guaranteed that given graph is a tree. Output Print "Yes" (without quotes), if given graph is k-multihedgehog, and "No" (without quotes) otherwise. Examples Input 14 2 1 4 2 4 3 4 4 13 10 5 11 5 12 5 14 5 5 13 6 7 8 6 13 6 9 6 Output Yes Input 3 1 1 3 2 3 Output No Note 2-multihedgehog from the first example looks like this: <image> Its center is vertex 13. Hedgehogs created on last step are: [4 (center), 1, 2, 3], [6 (center), 7, 8, 9], [5 (center), 10, 11, 12, 13]. Tree from second example is not a hedgehog because degree of center should be at least 3. Submitted Solution: ``` import os import sys from io import BytesIO, IOBase # region fastio BUFSIZE = 8192 class FastIO(IOBase): newlines = 0 def __init__(self, file): self._fd = file.fileno() self.buffer = BytesIO() self.writable = "x" in file.mode or "r" not in file.mode self.write = self.buffer.write if self.writable else None def read(self): while True: b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE)) if not b: break ptr = self.buffer.tell() self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr) self.newlines = 0 return self.buffer.read() def readline(self): while self.newlines == 0: b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE)) self.newlines = b.count(b"\n") + (not b) ptr = self.buffer.tell() self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr) self.newlines -= 1 return self.buffer.readline() def flush(self): if self.writable: os.write(self._fd, self.buffer.getvalue()) self.buffer.truncate(0), self.buffer.seek(0) class IOWrapper(IOBase): def __init__(self, file): self.buffer = FastIO(file) self.flush = self.buffer.flush self.writable = self.buffer.writable self.write = lambda s: self.buffer.write(s.encode("ascii")) self.read = lambda: self.buffer.read().decode("ascii") self.readline = lambda: self.buffer.readline().decode("ascii") sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout) input = lambda: sys.stdin.readline().rstrip("\r\n") # ------------------------------ def RL(): return map(int, sys.stdin.readline().rstrip().split()) def RLL(): return list(map(int, sys.stdin.readline().rstrip().split())) def N(): return int(input()) def comb(n, m): return factorial(n) / (factorial(m) * factorial(n - m)) if n >= m else 0 def perm(n, m): return factorial(n) // (factorial(n - m)) if n >= m else 0 def mdis(x1, y1, x2, y2): return abs(x1 - x2) + abs(y1 - y2) def toord(c): return ord(c)-ord('a') def lcm(a, b): return a*b//lcm(a, b) mod = 998244353 INF = float('inf') from math import factorial, sqrt, ceil, floor, gcd from collections import Counter, defaultdict, deque from heapq import heapify, heappop, heappush # ------------------------------ # f = open('./input.txt') # sys.stdin = f def main(): n, k = RL() ind = [0]*(n+1) gp = [[] for _ in range(n+1)] for _ in range(n-1): f, t = RL() ind[f]+=1 ind[t]+=1 gp[f].append(t) gp[t].append(f) orind = ind.copy() if not any(len(gp[i]) >= 3 for i in range(n+1)): print('No') sys.exit() q = [] for i in range(1, n+1): if ind[i]==1: q.append(i) tag = False num = 0 rec = [] ct = -1 while q: nq = [] num+=1 while q: nd = q.pop() for nex in gp[nd]: ind[nex]-=1 if ind[nex]==1: rec.append(nex) nq.append(nex) q = nq if len(q)==1 and ind[q[0]]==0: ct = q[0] for i in rec: if (i!=ct and orind[i]<4) or orind[i]<3: tag = True if tag or num!=k+1 or ct==-1: print('No') else: print('Yes') if __name__ == "__main__": main() ```
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Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. Someone give a strange birthday present to Ivan. It is hedgehog — connected undirected graph in which one vertex has degree at least 3 (we will call it center) and all other vertices has degree 1. Ivan thought that hedgehog is too boring and decided to make himself k-multihedgehog. Let us define k-multihedgehog as follows: * 1-multihedgehog is hedgehog: it has one vertex of degree at least 3 and some vertices of degree 1. * For all k ≥ 2, k-multihedgehog is (k-1)-multihedgehog in which the following changes has been made for each vertex v with degree 1: let u be its only neighbor; remove vertex v, create a new hedgehog with center at vertex w and connect vertices u and w with an edge. New hedgehogs can differ from each other and the initial gift. Thereby k-multihedgehog is a tree. Ivan made k-multihedgehog but he is not sure that he did not make any mistakes. That is why he asked you to check if his tree is indeed k-multihedgehog. Input First line of input contains 2 integers n, k (1 ≤ n ≤ 10^{5}, 1 ≤ k ≤ 10^{9}) — number of vertices and hedgehog parameter. Next n-1 lines contains two integers u v (1 ≤ u, v ≤ n; u ≠ v) — indices of vertices connected by edge. It is guaranteed that given graph is a tree. Output Print "Yes" (without quotes), if given graph is k-multihedgehog, and "No" (without quotes) otherwise. Examples Input 14 2 1 4 2 4 3 4 4 13 10 5 11 5 12 5 14 5 5 13 6 7 8 6 13 6 9 6 Output Yes Input 3 1 1 3 2 3 Output No Note 2-multihedgehog from the first example looks like this: <image> Its center is vertex 13. Hedgehogs created on last step are: [4 (center), 1, 2, 3], [6 (center), 7, 8, 9], [5 (center), 10, 11, 12, 13]. Tree from second example is not a hedgehog because degree of center should be at least 3. Submitted Solution: ``` # ---------------------------iye ha aam zindegi--------------------------------------------- import math import heapq, bisect import sys from collections import deque, defaultdict from fractions import Fraction import sys mod = 10 ** 9 + 7 mod1 = 998244353 # ------------------------------warmup---------------------------- import os import sys from io import BytesIO, IOBase BUFSIZE = 8192 sys.setrecursionlimit(300000) class FastIO(IOBase): newlines = 0 def __init__(self, file): self._fd = file.fileno() self.buffer = BytesIO() self.writable = "x" in file.mode or "r" not in file.mode self.write = self.buffer.write if self.writable else None def read(self): while True: b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE)) if not b: break ptr = self.buffer.tell() self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr) self.newlines = 0 return self.buffer.read() def readline(self): while self.newlines == 0: b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE)) self.newlines = b.count(b"\n") + (not b) ptr = self.buffer.tell() self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr) self.newlines -= 1 return self.buffer.readline() def flush(self): if self.writable: os.write(self._fd, self.buffer.getvalue()) self.buffer.truncate(0), self.buffer.seek(0) class IOWrapper(IOBase): def __init__(self, file): self.buffer = FastIO(file) self.flush = self.buffer.flush self.writable = self.buffer.writable self.write = lambda s: self.buffer.write(s.encode("ascii")) self.read = lambda: self.buffer.read().decode("ascii") self.readline = lambda: self.buffer.readline().decode("ascii") sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout) input = lambda: sys.stdin.readline().rstrip("\r\n") # -------------------game starts now----------------------------------------------------import math class TreeNode: def __init__(self, k, v): self.key = k self.value = v self.left = None self.right = None self.parent = None self.height = 1 self.num_left = 1 self.num_total = 1 class AvlTree: def __init__(self): self._tree = None def add(self, k, v): if not self._tree: self._tree = TreeNode(k, v) return node = self._add(k, v) if node: self._rebalance(node) def _add(self, k, v): node = self._tree while node: if k < node.key: if node.left: node = node.left else: node.left = TreeNode(k, v) node.left.parent = node return node.left elif node.key < k: if node.right: node = node.right else: node.right = TreeNode(k, v) node.right.parent = node return node.right else: node.value = v return @staticmethod def get_height(x): return x.height if x else 0 @staticmethod def get_num_total(x): return x.num_total if x else 0 def _rebalance(self, node): n = node while n: lh = self.get_height(n.left) rh = self.get_height(n.right) n.height = max(lh, rh) + 1 balance_factor = lh - rh n.num_total = 1 + self.get_num_total(n.left) + self.get_num_total(n.right) n.num_left = 1 + self.get_num_total(n.left) if balance_factor > 1: if self.get_height(n.left.left) < self.get_height(n.left.right): self._rotate_left(n.left) self._rotate_right(n) elif balance_factor < -1: if self.get_height(n.right.right) < self.get_height(n.right.left): self._rotate_right(n.right) self._rotate_left(n) else: n = n.parent def _remove_one(self, node): """ Side effect!!! Changes node. Node should have exactly one child """ replacement = node.left or node.right if node.parent: if AvlTree._is_left(node): node.parent.left = replacement else: node.parent.right = replacement replacement.parent = node.parent node.parent = None else: self._tree = replacement replacement.parent = None node.left = None node.right = None node.parent = None self._rebalance(replacement) def _remove_leaf(self, node): if node.parent: if AvlTree._is_left(node): node.parent.left = None else: node.parent.right = None self._rebalance(node.parent) else: self._tree = None node.parent = None node.left = None node.right = None def remove(self, k): node = self._get_node(k) if not node: return if AvlTree._is_leaf(node): self._remove_leaf(node) return if node.left and node.right: nxt = AvlTree._get_next(node) node.key = nxt.key node.value = nxt.value if self._is_leaf(nxt): self._remove_leaf(nxt) else: self._remove_one(nxt) self._rebalance(node) else: self._remove_one(node) def get(self, k): node = self._get_node(k) return node.value if node else -1 def _get_node(self, k): if not self._tree: return None node = self._tree while node: if k < node.key: node = node.left elif node.key < k: node = node.right else: return node return None def get_at(self, pos): x = pos + 1 node = self._tree while node: if x < node.num_left: node = node.left elif node.num_left < x: x -= node.num_left node = node.right else: return (node.key, node.value) raise IndexError("Out of ranges") @staticmethod def _is_left(node): return node.parent.left and node.parent.left == node @staticmethod def _is_leaf(node): return node.left is None and node.right is None def _rotate_right(self, node): if not node.parent: self._tree = node.left node.left.parent = None elif AvlTree._is_left(node): node.parent.left = node.left node.left.parent = node.parent else: node.parent.right = node.left node.left.parent = node.parent bk = node.left.right node.left.right = node node.parent = node.left node.left = bk if bk: bk.parent = node node.height = max(self.get_height(node.left), self.get_height(node.right)) + 1 node.num_total = 1 + self.get_num_total(node.left) + self.get_num_total(node.right) node.num_left = 1 + self.get_num_total(node.left) def _rotate_left(self, node): if not node.parent: self._tree = node.right node.right.parent = None elif AvlTree._is_left(node): node.parent.left = node.right node.right.parent = node.parent else: node.parent.right = node.right node.right.parent = node.parent bk = node.right.left node.right.left = node node.parent = node.right node.right = bk if bk: bk.parent = node node.height = max(self.get_height(node.left), self.get_height(node.right)) + 1 node.num_total = 1 + self.get_num_total(node.left) + self.get_num_total(node.right) node.num_left = 1 + self.get_num_total(node.left) @staticmethod def _get_next(node): if not node.right: return node.parent n = node.right while n.left: n = n.left return n # -----------------------------------------------binary seacrh tree--------------------------------------- class SegmentTree1: def __init__(self, data, default=0, func=lambda a, b: max(a, b)): """initialize the segment tree with data""" self._default = default self._func = func self._len = len(data) self._size = _size = 1 << (self._len - 1).bit_length() self.data = [default] * (2 * _size) self.data[_size:_size + self._len] = data for i in reversed(range(_size)): self.data[i] = func(self.data[i + i], self.data[i + i + 1]) def __delitem__(self, idx): self[idx] = self._default def __getitem__(self, idx): return self.data[idx + self._size] def __setitem__(self, idx, value): idx += self._size self.data[idx] = value idx >>= 1 while idx: self.data[idx] = self._func(self.data[2 * idx], self.data[2 * idx + 1]) idx >>= 1 def __len__(self): return self._len def query(self, start, stop): if start == stop: return self.__getitem__(start) stop += 1 start += self._size stop += self._size res = self._default while start < stop: if start & 1: res = self._func(res, self.data[start]) start += 1 if stop & 1: stop -= 1 res = self._func(res, self.data[stop]) start >>= 1 stop >>= 1 return res def __repr__(self): return "SegmentTree({0})".format(self.data) # -------------------game starts now----------------------------------------------------import math class SegmentTree: def __init__(self, data, default=0, func=lambda a, b: a + b): """initialize the segment tree with data""" self._default = default self._func = func self._len = len(data) self._size = _size = 1 << (self._len - 1).bit_length() self.data = [default] * (2 * _size) self.data[_size:_size + self._len] = data for i in reversed(range(_size)): self.data[i] = func(self.data[i + i], self.data[i + i + 1]) def __delitem__(self, idx): self[idx] = self._default def __getitem__(self, idx): return self.data[idx + self._size] def __setitem__(self, idx, value): idx += self._size self.data[idx] = value idx >>= 1 while idx: self.data[idx] = self._func(self.data[2 * idx], self.data[2 * idx + 1]) idx >>= 1 def __len__(self): return self._len def query(self, start, stop): if start == stop: return self.__getitem__(start) stop += 1 start += self._size stop += self._size res = self._default while start < stop: if start & 1: res = self._func(res, self.data[start]) start += 1 if stop & 1: stop -= 1 res = self._func(res, self.data[stop]) start >>= 1 stop >>= 1 return res def __repr__(self): return "SegmentTree({0})".format(self.data) # -------------------------------iye ha chutiya zindegi------------------------------------- class Factorial: def __init__(self, MOD): self.MOD = MOD self.factorials = [1, 1] self.invModulos = [0, 1] self.invFactorial_ = [1, 1] def calc(self, n): if n <= -1: print("Invalid argument to calculate n!") print("n must be non-negative value. But the argument was " + str(n)) exit() if n < len(self.factorials): return self.factorials[n] nextArr = [0] * (n + 1 - len(self.factorials)) initialI = len(self.factorials) prev = self.factorials[-1] m = self.MOD for i in range(initialI, n + 1): prev = nextArr[i - initialI] = prev * i % m self.factorials += nextArr return self.factorials[n] def inv(self, n): if n <= -1: print("Invalid argument to calculate n^(-1)") print("n must be non-negative value. But the argument was " + str(n)) exit() p = self.MOD pi = n % p if pi < len(self.invModulos): return self.invModulos[pi] nextArr = [0] * (n + 1 - len(self.invModulos)) initialI = len(self.invModulos) for i in range(initialI, min(p, n + 1)): next = -self.invModulos[p % i] * (p // i) % p self.invModulos.append(next) return self.invModulos[pi] def invFactorial(self, n): if n <= -1: print("Invalid argument to calculate (n^(-1))!") print("n must be non-negative value. But the argument was " + str(n)) exit() if n < len(self.invFactorial_): return self.invFactorial_[n] self.inv(n) # To make sure already calculated n^-1 nextArr = [0] * (n + 1 - len(self.invFactorial_)) initialI = len(self.invFactorial_) prev = self.invFactorial_[-1] p = self.MOD for i in range(initialI, n + 1): prev = nextArr[i - initialI] = (prev * self.invModulos[i % p]) % p self.invFactorial_ += nextArr return self.invFactorial_[n] class Combination: def __init__(self, MOD): self.MOD = MOD self.factorial = Factorial(MOD) def ncr(self, n, k): if k < 0 or n < k: return 0 k = min(k, n - k) f = self.factorial return f.calc(n) * f.invFactorial(max(n - k, k)) * f.invFactorial(min(k, n - k)) % self.MOD # --------------------------------------iye ha combinations ka zindegi--------------------------------- def powm(a, n, m): if a == 1 or n == 0: return 1 if n % 2 == 0: s = powm(a, n // 2, m) return s * s % m else: return a * powm(a, n - 1, m) % m # --------------------------------------iye ha power ka zindegi--------------------------------- def sort_list(list1, list2): zipped_pairs = zip(list2, list1) z = [x for _, x in sorted(zipped_pairs)] return z # --------------------------------------------------product---------------------------------------- def product(l): por = 1 for i in range(len(l)): por *= l[i] return por # --------------------------------------------------binary---------------------------------------- def binarySearchCount(arr, n, key): left = 0 right = n - 1 count = 0 while (left <= right): mid = int((right + left) / 2) # Check if middle element is # less than or equal to key if (arr[mid] < key): count = mid + 1 left = mid + 1 # If key is smaller, ignore right half else: right = mid - 1 return count # --------------------------------------------------binary---------------------------------------- def countdig(n): c = 0 while (n > 0): n //= 10 c += 1 return c def binary(x, length): y = bin(x)[2:] return y if len(y) >= length else "0" * (length - len(y)) + y def countGreater(arr, n, k): l = 0 r = n - 1 # Stores the index of the left most element # from the array which is greater than k leftGreater = n # Finds number of elements greater than k while (l <= r): m = int(l + (r - l) / 2) if (arr[m] >= k): leftGreater = m r = m - 1 # If mid element is less than # or equal to k update l else: l = m + 1 # Return the count of elements # greater than k return (n - leftGreater) # --------------------------------------------------binary------------------------------------ n,k=map(int,input().split()) graph=defaultdict(list) deg=[0]*n for i in range(n-1): a,b=map(int,input().split()) graph[a-1].append(b-1) graph[b-1].append(a-1) deg[a-1]+=1 deg[b-1]+=1 for i in range(n): if deg[i]==2: print("No") if n == 88573: print(1234) sys.exit(0) s=set() for i in range(n): if deg[i]==1: if len(s)<2: s.add(graph[i][0]) if deg[graph[i][0]]<3: if n == 88573: print(4123) print("No") sys.exit(0) f=0 e=set() for i in s: for j in graph[i]: if deg[j]==1: e.add(j) break if len(e)==2: break e=list(e) dis=[0]*n def BFS(s,des): visited = [False] * (len(graph)) pre=[-1]*n queue = [] queue.append(s) visited[s] = True while queue: s = queue.pop(0) for i in graph[s]: if visited[i] == False: visited[i]=True pre[i]=s dis[i]=dis[s]+1 queue.append(i) if i==des: return pre return pre def DFS(v,visited,dep): visited[v] = True r=0 for i in graph[v]: if visited[i] == False: r+=DFS(i, visited,dep+1) if deg[v]==1 and dep!=k: return -1 else: return r pre=BFS(e[0],e[1]) r=e[1] e=[r] er=r for i in range(dis[e[0]]): e.append(pre[er]) er=pre[er] center=e[len(e)//2] for i in range(n): if deg[i]==3 and i!=center: if n == 88573: print(1235,center,deg[center],i,deg[i]) print("No") sys.exit(0) f=DFS(center,[False]*n,0) if f==0: print("Yes") else: if n==88573: print(123) print("No") ```
instruction
0
90,137
13
180,274
No
output
1
90,137
13
180,275
Provide tags and a correct Python 3 solution for this coding contest problem. You are given a tree (an undirected connected acyclic graph) consisting of n vertices and n - 1 edges. A number is written on each edge, each number is either 0 (let's call such edges 0-edges) or 1 (those are 1-edges). Let's call an ordered pair of vertices (x, y) (x ≠ y) valid if, while traversing the simple path from x to y, we never go through a 0-edge after going through a 1-edge. Your task is to calculate the number of valid pairs in the tree. Input The first line contains one integer n (2 ≤ n ≤ 200000) — the number of vertices in the tree. Then n - 1 lines follow, each denoting an edge of the tree. Each edge is represented by three integers x_i, y_i and c_i (1 ≤ x_i, y_i ≤ n, 0 ≤ c_i ≤ 1, x_i ≠ y_i) — the vertices connected by this edge and the number written on it, respectively. It is guaranteed that the given edges form a tree. Output Print one integer — the number of valid pairs of vertices. Example Input 7 2 1 1 3 2 0 4 2 1 5 2 0 6 7 1 7 2 1 Output 34 Note The picture corresponding to the first example: <image>
instruction
0
90,182
13
180,364
Tags: dfs and similar, divide and conquer, dp, dsu, trees Correct Solution: ``` import sys input = sys.stdin.readline class DSU: # Disjoint Set Union (Union-Find) Data Structure def __init__(self, nodes): # Dictionary of parents self.p = [i for i in range(nodes)] # Dictionary of ranks self.r = [0 for i in range(nodes)] # Dictionary of sizes self.s = [1 for i in range(nodes)] def nonrecurive_get(self, u): # Returns the identifier of the set that contains u, includes path compression v = u while self.p[v] != v: v = self.p[v] while self.p[u] != u: u, self.p[u] = self.p[u], v return u def get(self, u): # Recursive Returns the identifier of the set that contains u, includes path compression if u != self.p[u]: self.p[u] = self.get(self.p[u]) return self.p[u] def union(self, u, v): # Unites the sets with identifiers u and v u = self.get(u) v = self.get(v) if u != v: if self.r[u] > self.r[v]: u, v = v, u self.p[u] = v if self.r[u] == self.r[v]: self.r[v] += 1 self.s[v] += self.s[u] def size(self, u): u = self.get(u) return self.s[u] def solve(): n = int(input()) dsus = [DSU(n), DSU(n)] for edge in range(n - 1): x, y, c = [int(s) for s in input().split(' ')] dsus[c].union(x - 1, y - 1) S = 0 for v in range(n): S += (dsus[0].size(v) * dsus[1].size(v) - 1) return S print(solve()) ```
output
1
90,182
13
180,365
Provide tags and a correct Python 3 solution for this coding contest problem. You are given a tree (an undirected connected acyclic graph) consisting of n vertices and n - 1 edges. A number is written on each edge, each number is either 0 (let's call such edges 0-edges) or 1 (those are 1-edges). Let's call an ordered pair of vertices (x, y) (x ≠ y) valid if, while traversing the simple path from x to y, we never go through a 0-edge after going through a 1-edge. Your task is to calculate the number of valid pairs in the tree. Input The first line contains one integer n (2 ≤ n ≤ 200000) — the number of vertices in the tree. Then n - 1 lines follow, each denoting an edge of the tree. Each edge is represented by three integers x_i, y_i and c_i (1 ≤ x_i, y_i ≤ n, 0 ≤ c_i ≤ 1, x_i ≠ y_i) — the vertices connected by this edge and the number written on it, respectively. It is guaranteed that the given edges form a tree. Output Print one integer — the number of valid pairs of vertices. Example Input 7 2 1 1 3 2 0 4 2 1 5 2 0 6 7 1 7 2 1 Output 34 Note The picture corresponding to the first example: <image>
instruction
0
90,183
13
180,366
Tags: dfs and similar, divide and conquer, dp, dsu, trees Correct Solution: ``` class UnionFind: def __init__(self, N): self.par = [i for i in range(N)] self.rank = [1 for i in range(N)] self.rank[0] = 0 def union(self, x, y): if not self.is_same_set(x, y): par_x = self.find_par(x) par_y = self.find_par(y) if self.rank[par_x] > self.rank[par_y]: self.rank[par_x] += self.rank[par_y] self.rank[par_y] = 0 self.par[par_y] = par_x else: self.rank[par_y] += self.rank[par_x] self.rank[par_x] = 0 self.par[par_x] = par_y def find_par(self, x): if self.par[x] == x: return x self.par[x] = self.find_par(self.par[x]) return self.par[x] def is_same_set(self, x, y): return self.find_par(x) == self.find_par(y) def size(self, x): return self.rank[self.find_par(x)] # 2 unionfind, para 0 e para 1 formando 2 florestas # lista de adj # verificar todos os componentes existentes e adicionar na resposta n * (n-1) n = int(input()) adj = [[] for i in range(n+1)] uf0 = UnionFind(n+1) uf1 = UnionFind(n+1) for i in range(n-1): x, y, c = map(int, input().split()) if c == 0: uf0.union(x, y) else: uf1.union(x, y) adj[x].append(y) adj[y].append(x) for i in range(n+1): uf0.find_par(i) uf1.find_par(i) resp = 0 for i in set(uf0.par): resp += uf0.rank[i] * (uf0.rank[i] - 1) for i in set(uf1.par): resp += uf1.rank[i] * (uf1.rank[i] - 1) # pra cada componente do 0-uf verificar se existe esse vertice na 1-uf e ele for conectado com alguém, se sim, multiplicar (n-1)*(m-1) sendo n o componente da 0-uf e m o componente da 1-f e adicionar na resposta for i in range(len(uf0.par)): if uf0.rank[uf0.find_par(i)] > 1: if uf1.rank[uf1.find_par(i)] > 1: resp += (uf0.rank[uf0.find_par(i)] - 1) * (uf1.rank[uf1.find_par(i)] - 1) print(resp) ```
output
1
90,183
13
180,367
Provide tags and a correct Python 3 solution for this coding contest problem. You are given a tree (an undirected connected acyclic graph) consisting of n vertices and n - 1 edges. A number is written on each edge, each number is either 0 (let's call such edges 0-edges) or 1 (those are 1-edges). Let's call an ordered pair of vertices (x, y) (x ≠ y) valid if, while traversing the simple path from x to y, we never go through a 0-edge after going through a 1-edge. Your task is to calculate the number of valid pairs in the tree. Input The first line contains one integer n (2 ≤ n ≤ 200000) — the number of vertices in the tree. Then n - 1 lines follow, each denoting an edge of the tree. Each edge is represented by three integers x_i, y_i and c_i (1 ≤ x_i, y_i ≤ n, 0 ≤ c_i ≤ 1, x_i ≠ y_i) — the vertices connected by this edge and the number written on it, respectively. It is guaranteed that the given edges form a tree. Output Print one integer — the number of valid pairs of vertices. Example Input 7 2 1 1 3 2 0 4 2 1 5 2 0 6 7 1 7 2 1 Output 34 Note The picture corresponding to the first example: <image>
instruction
0
90,184
13
180,368
Tags: dfs and similar, divide and conquer, dp, dsu, trees Correct Solution: ``` class Deque: def __init__(self): self.buff = [0] * 400000 self.l = 0 self.r = 0 def append(self, x): self.buff[self.r] = x self.r = self.r + 1 def popleft(self): old_left = self.l self.l = self.l + 1 return self.buff[old_left] def __bool__(self): return self.l != self.r q = Deque() def bfs(source, graph, mark, num, fcount): visited = [source] mark[source] = True q.append(source) while q: u = q.popleft() for v, c in g[u]: if c == num and not mark[v]: mark[v] = True visited.append(v) q.append(v) if len(visited) > 1: for u in visited: fcount[u] = len(visited) n = int(input()) edges = [tuple(map(int, input().split())) for _ in range(0, n - 1)] g = [[] for _ in range(0, n)] cnt = [[0 for _ in range(0, n)] for _ in range(0, 2)] for u, v, c in edges: g[u - 1].append((v - 1, c)) g[v - 1].append((u - 1, c)) res = 0 for link in range(0, 2): mark = [False] * n for u in range(0, n): if not mark[u]: bfs(u, g, mark, link, cnt[link]) res += cnt[link][u] * (cnt[link][u] - 1) for i in range(0, n): if cnt[0][i] > 0 and cnt[1][i] > 1: res += (cnt[0][i] - 1) * (cnt[1][i] - 1) print(int(res)) ```
output
1
90,184
13
180,369
Provide tags and a correct Python 3 solution for this coding contest problem. You are given a tree (an undirected connected acyclic graph) consisting of n vertices and n - 1 edges. A number is written on each edge, each number is either 0 (let's call such edges 0-edges) or 1 (those are 1-edges). Let's call an ordered pair of vertices (x, y) (x ≠ y) valid if, while traversing the simple path from x to y, we never go through a 0-edge after going through a 1-edge. Your task is to calculate the number of valid pairs in the tree. Input The first line contains one integer n (2 ≤ n ≤ 200000) — the number of vertices in the tree. Then n - 1 lines follow, each denoting an edge of the tree. Each edge is represented by three integers x_i, y_i and c_i (1 ≤ x_i, y_i ≤ n, 0 ≤ c_i ≤ 1, x_i ≠ y_i) — the vertices connected by this edge and the number written on it, respectively. It is guaranteed that the given edges form a tree. Output Print one integer — the number of valid pairs of vertices. Example Input 7 2 1 1 3 2 0 4 2 1 5 2 0 6 7 1 7 2 1 Output 34 Note The picture corresponding to the first example: <image>
instruction
0
90,185
13
180,370
Tags: dfs and similar, divide and conquer, dp, dsu, trees Correct Solution: ``` import sys;sys.setrecursionlimit(10**9) class UnionFind: def __init__(self,n): self.n=[-1]*n self.r=[0]*n self.siz=n def find_root(self,x): if self.n[x]<0: return x else: self.n[x]=self.find_root(self.n[x]) return self.n[x] def unite(self,x,y): x=self.find_root(x) y=self.find_root(y) if x==y:return elif self.r[x]>self.r[y]: self.n[x]+=self.n[y] self.n[y]=x else: self.n[y]+=self.n[x] self.n[x]=y if self.r[x]==self.r[y]: self.r[y]+=1 self.siz-=1 def root_same(self,x,y): return self.find_root(x)==self.find_root(y) def count(self,x): return -self.n[self.find_root(x)] def size(self): return self.siz n=int(input()) ouf=UnionFind(n) zuf=UnionFind(n) for _ in range(n-1): a,b,c=map(int,input().split()) a-=1 b-=1 if c==0: zuf.unite(a,b) else: ouf.unite(a,b) ans=0 for i in range(n): m=zuf.count(i) if zuf.find_root(i)==i:ans+=m*(m-1) mm=ouf.count(i) if ouf.find_root(i)==i:ans+=mm*(mm-1) ans+=(m-1)*(mm-1) print(ans) ```
output
1
90,185
13
180,371
Provide tags and a correct Python 3 solution for this coding contest problem. You are given a tree (an undirected connected acyclic graph) consisting of n vertices and n - 1 edges. A number is written on each edge, each number is either 0 (let's call such edges 0-edges) or 1 (those are 1-edges). Let's call an ordered pair of vertices (x, y) (x ≠ y) valid if, while traversing the simple path from x to y, we never go through a 0-edge after going through a 1-edge. Your task is to calculate the number of valid pairs in the tree. Input The first line contains one integer n (2 ≤ n ≤ 200000) — the number of vertices in the tree. Then n - 1 lines follow, each denoting an edge of the tree. Each edge is represented by three integers x_i, y_i and c_i (1 ≤ x_i, y_i ≤ n, 0 ≤ c_i ≤ 1, x_i ≠ y_i) — the vertices connected by this edge and the number written on it, respectively. It is guaranteed that the given edges form a tree. Output Print one integer — the number of valid pairs of vertices. Example Input 7 2 1 1 3 2 0 4 2 1 5 2 0 6 7 1 7 2 1 Output 34 Note The picture corresponding to the first example: <image>
instruction
0
90,186
13
180,372
Tags: dfs and similar, divide and conquer, dp, dsu, trees Correct Solution: ``` from collections import defaultdict def colour(a, graph, cur, i): top = set() top.add(i) while len(top): x = top.pop() a[x] = cur for y in graph[x]: if a[y] == 0: top.add(y) def colour_graph(a, graph, n): cur = 0 for i in range(1, n + 1): if a[i] or i not in graph: continue else: cur += 1 colour(a, graph, cur, i) def count(col): ans = 0 for el in col: if col[el] > 1: ans += col[el]*(col[el] - 1) return ans n = int(input()) graph0 = defaultdict(set) graph1 = defaultdict(set) vertex0 = set() a0 = [0]*(n + 1) a1 = [0]*(n + 1) for i in range(n - 1): x, y, c = map(int, input().split()) if c == 0: graph0[x].add(y) graph0[y].add(x) vertex0.add(x) vertex0.add(y) else: graph1[x].add(y) graph1[y].add(x) colour_graph(a0, graph0, n) colour_graph(a1, graph1, n) answer = 0 col0 = defaultdict(int) col1 = defaultdict(int) for i in range(n + 1): if a0[i]: col0[a0[i]] += 1 if a1[i]: col1[a1[i]] += 1 answer += count(col0) + count(col1) col = defaultdict(int) for v in vertex0: col[a1[v]] += col0[a0[v]] - 1 for el in col: if el: answer += col[el]*(col1[el] - 1) print(answer) ```
output
1
90,186
13
180,373
Provide tags and a correct Python 3 solution for this coding contest problem. You are given a tree (an undirected connected acyclic graph) consisting of n vertices and n - 1 edges. A number is written on each edge, each number is either 0 (let's call such edges 0-edges) or 1 (those are 1-edges). Let's call an ordered pair of vertices (x, y) (x ≠ y) valid if, while traversing the simple path from x to y, we never go through a 0-edge after going through a 1-edge. Your task is to calculate the number of valid pairs in the tree. Input The first line contains one integer n (2 ≤ n ≤ 200000) — the number of vertices in the tree. Then n - 1 lines follow, each denoting an edge of the tree. Each edge is represented by three integers x_i, y_i and c_i (1 ≤ x_i, y_i ≤ n, 0 ≤ c_i ≤ 1, x_i ≠ y_i) — the vertices connected by this edge and the number written on it, respectively. It is guaranteed that the given edges form a tree. Output Print one integer — the number of valid pairs of vertices. Example Input 7 2 1 1 3 2 0 4 2 1 5 2 0 6 7 1 7 2 1 Output 34 Note The picture corresponding to the first example: <image>
instruction
0
90,187
13
180,374
Tags: dfs and similar, divide and conquer, dp, dsu, trees Correct Solution: ``` n = int(input()) class UnionFind(object): def __init__(self, n): # 初始化uf数组和组数目 self.count = n self.uf = [i for i in range(n)] self.size = [1] * n # 每个联通分量的size def find(self, x): # 判断节点所属于的组 while x != self.uf[x]: self.uf[x] = self.uf[self.uf[x]] x = self.uf[x] return self.uf[x] def union(self, x, y): # 连接两个节点 x_root = self.find(x) y_root = self.find(y) if x_root == y_root: return if self.size[x_root] < self.size[y_root]: x_root, y_root = y_root, x_root self.uf[y_root] = x_root self.size[x_root] += self.size[y_root] self.size[y_root] = 0 self.count -= 1 uf0 = UnionFind(n) uf1 = UnionFind(n) for i in range(n - 1): a, b, c = [int(j) for j in input().split(' ')] if c == 0: uf0.union(a-1, b-1) else: uf1.union(a-1, b-1) res = 0 from collections import * cnt0 = Counter(uf0.find(k) for k in range(n)) cnt1 = Counter(uf1.find(k) for k in range(n)) for c0, n0 in cnt0.items(): res += n0 * (n0 - 1) for c1, n1 in cnt1.items(): res += n1 * (n1 - 1) for i in range(n): n0 = cnt0[uf0.find(i)] n1 = cnt1[uf1.find(i)] res += (n0 - 1) * (n1 - 1) print(res) """ 7 2 1 1 3 2 0 4 2 1 5 2 0 6 7 1 7 2 1 """ ```
output
1
90,187
13
180,375
Provide tags and a correct Python 3 solution for this coding contest problem. You are given a tree (an undirected connected acyclic graph) consisting of n vertices and n - 1 edges. A number is written on each edge, each number is either 0 (let's call such edges 0-edges) or 1 (those are 1-edges). Let's call an ordered pair of vertices (x, y) (x ≠ y) valid if, while traversing the simple path from x to y, we never go through a 0-edge after going through a 1-edge. Your task is to calculate the number of valid pairs in the tree. Input The first line contains one integer n (2 ≤ n ≤ 200000) — the number of vertices in the tree. Then n - 1 lines follow, each denoting an edge of the tree. Each edge is represented by three integers x_i, y_i and c_i (1 ≤ x_i, y_i ≤ n, 0 ≤ c_i ≤ 1, x_i ≠ y_i) — the vertices connected by this edge and the number written on it, respectively. It is guaranteed that the given edges form a tree. Output Print one integer — the number of valid pairs of vertices. Example Input 7 2 1 1 3 2 0 4 2 1 5 2 0 6 7 1 7 2 1 Output 34 Note The picture corresponding to the first example: <image>
instruction
0
90,188
13
180,376
Tags: dfs and similar, divide and conquer, dp, dsu, trees Correct Solution: ``` class UnionFind(): def __init__(self, n): self.n = n self.root = [-1]*(n+1) self.rnk = [0]*(n+1) def Find_Root(self, x): if(self.root[x] < 0): return x else: self.root[x] = self.Find_Root(self.root[x]) return self.root[x] def Unite(self, x, y): x = self.Find_Root(x) y = self.Find_Root(y) if(x == y): return elif(self.rnk[x] > self.rnk[y]): self.root[x] += self.root[y] self.root[y] = x else: self.root[y] += self.root[x] self.root[x] = y if(self.rnk[x] == self.rnk[y]): self.rnk[y] += 1 def isSameGroup(self, x, y): return self.Find_Root(x) == self.Find_Root(y) def Count(self, x): return -self.root[self.Find_Root(x)] import sys input = sys.stdin.readline N = int(input()) uni0 = UnionFind(N) uni1 = UnionFind(N) for _ in range(N-1): a, b, c = map(int, input().split()) if c == 0: uni0.Unite(a-1, b-1) else: uni1.Unite(a-1, b-1) g0 = {} g1 = {} for i in range(N): if uni0.Count(i) != 1: r = uni0.Find_Root(i) if not r in g0.keys(): g0[r] = [i] else: g0[r].append(i) if uni1.Count(i) != 1: r = uni1.Find_Root(i) if not r in g1.keys(): g1[r] = [i] else: g1[r].append(i) ans = 0 for v_list in g1.values(): c = 0 for n in v_list: if uni0.Count(n) == 1: c += 1 l = len(v_list) ans += c*(l-1) for v_list in g0.values(): c = 0 for n in v_list: if uni1.Count(n) != 1: r = uni1.Find_Root(n) c += len(g1[r])-1 c += len(v_list)-1 ans += len(v_list)*c print(ans) ```
output
1
90,188
13
180,377
Provide tags and a correct Python 3 solution for this coding contest problem. You are given a tree (an undirected connected acyclic graph) consisting of n vertices and n - 1 edges. A number is written on each edge, each number is either 0 (let's call such edges 0-edges) or 1 (those are 1-edges). Let's call an ordered pair of vertices (x, y) (x ≠ y) valid if, while traversing the simple path from x to y, we never go through a 0-edge after going through a 1-edge. Your task is to calculate the number of valid pairs in the tree. Input The first line contains one integer n (2 ≤ n ≤ 200000) — the number of vertices in the tree. Then n - 1 lines follow, each denoting an edge of the tree. Each edge is represented by three integers x_i, y_i and c_i (1 ≤ x_i, y_i ≤ n, 0 ≤ c_i ≤ 1, x_i ≠ y_i) — the vertices connected by this edge and the number written on it, respectively. It is guaranteed that the given edges form a tree. Output Print one integer — the number of valid pairs of vertices. Example Input 7 2 1 1 3 2 0 4 2 1 5 2 0 6 7 1 7 2 1 Output 34 Note The picture corresponding to the first example: <image>
instruction
0
90,189
13
180,378
Tags: dfs and similar, divide and conquer, dp, dsu, trees Correct Solution: ``` from collections import deque from sys import stdin def bfs(source, graph, mark, num, fcount): visited = [source] q = deque() mark[source] = True q.append(source) while q: u = q.popleft() for v in graph[u]: if not mark[v]: mark[v] = True visited.append(v) q.append(v) for u in visited: fcount[u] = len(visited) n = int(stdin.readline()) g = [[[] for _ in range(0, n)] for _ in range(0, 2)] cnt = [[0 for _ in range(0, n)] for _ in range(0, 2)] for line in stdin.readlines(): u, v, c = map(int, line.split()) g[c][u - 1].append(v - 1) g[c][v - 1].append(u - 1) res = 0 for link in range(0, 2): mark = [False] * n for u in range(0, n): if not mark[u] and len(g[link][u]) > 0: bfs(u, g[link], mark, link, cnt[link]) res += cnt[link][u] * (cnt[link][u] - 1) for i in range(0, n): if cnt[0][i] > 0 and cnt[1][i] > 1: res += (cnt[0][i] - 1) * (cnt[1][i] - 1) print(int(res)) ```
output
1
90,189
13
180,379
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. You are given a tree (an undirected connected acyclic graph) consisting of n vertices and n - 1 edges. A number is written on each edge, each number is either 0 (let's call such edges 0-edges) or 1 (those are 1-edges). Let's call an ordered pair of vertices (x, y) (x ≠ y) valid if, while traversing the simple path from x to y, we never go through a 0-edge after going through a 1-edge. Your task is to calculate the number of valid pairs in the tree. Input The first line contains one integer n (2 ≤ n ≤ 200000) — the number of vertices in the tree. Then n - 1 lines follow, each denoting an edge of the tree. Each edge is represented by three integers x_i, y_i and c_i (1 ≤ x_i, y_i ≤ n, 0 ≤ c_i ≤ 1, x_i ≠ y_i) — the vertices connected by this edge and the number written on it, respectively. It is guaranteed that the given edges form a tree. Output Print one integer — the number of valid pairs of vertices. Example Input 7 2 1 1 3 2 0 4 2 1 5 2 0 6 7 1 7 2 1 Output 34 Note The picture corresponding to the first example: <image> Submitted Solution: ``` from collections import deque from sys import stdin def bfs(source, graph, mark, fcount): visited = [source] q = deque() mark[source] = True q.append(source) while q: u = q.popleft() for v in graph[u]: if not mark[v]: mark[v] = True visited.append(v) q.append(v) for u in visited: fcount[u] = len(visited) def main(): n = int(stdin.readline()) g = [[[] for _ in range(0, n)] for _ in range(0, 2)] cnt = [[0 for _ in range(0, n)] for _ in range(0, 2)] for line in stdin.readlines(): u, v, c = map(int, line.split()) g[c][u - 1].append(v - 1) g[c][v - 1].append(u - 1) res = 0 for link in range(0, 2): mark = [False] * n for u in range(0, n): if not mark[u] and len(g[link][u]) > 0: bfs(u, g[link], mark, cnt[link]) res += cnt[link][u] * (cnt[link][u] - 1) for i in range(0, n): if cnt[0][i] > 0 and cnt[1][i] > 1: res += (cnt[0][i] - 1) * (cnt[1][i] - 1) print(int(res)) main() ```
instruction
0
90,190
13
180,380
Yes
output
1
90,190
13
180,381
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. You are given a tree (an undirected connected acyclic graph) consisting of n vertices and n - 1 edges. A number is written on each edge, each number is either 0 (let's call such edges 0-edges) or 1 (those are 1-edges). Let's call an ordered pair of vertices (x, y) (x ≠ y) valid if, while traversing the simple path from x to y, we never go through a 0-edge after going through a 1-edge. Your task is to calculate the number of valid pairs in the tree. Input The first line contains one integer n (2 ≤ n ≤ 200000) — the number of vertices in the tree. Then n - 1 lines follow, each denoting an edge of the tree. Each edge is represented by three integers x_i, y_i and c_i (1 ≤ x_i, y_i ≤ n, 0 ≤ c_i ≤ 1, x_i ≠ y_i) — the vertices connected by this edge and the number written on it, respectively. It is guaranteed that the given edges form a tree. Output Print one integer — the number of valid pairs of vertices. Example Input 7 2 1 1 3 2 0 4 2 1 5 2 0 6 7 1 7 2 1 Output 34 Note The picture corresponding to the first example: <image> Submitted Solution: ``` from collections import deque def bfs(source, graph, mark, num, fcount): visited = [source] q = deque() mark[source] = True q.append(source) while q: u = q.popleft() for v, c in g[u]: if c == num and not mark[v]: mark[v] = True visited.append(v) q.append(v) if len(visited) > 1: for u in visited: fcount[u] = len(visited) n = int(input()) edges = [tuple(map(int, input().split())) for _ in range(0, n - 1)] g = [[] for _ in range(0, n)] cnt = [[0 for _ in range(0, n)] for _ in range(0, 2)] for u, v, c in edges: g[u - 1].append((v - 1, c)) g[v - 1].append((u - 1, c)) res = 0 for link in range(0, 2): mark = [False] * n for u in range(0, n): if not mark[u]: bfs(u, g, mark, link, cnt[link]) res += cnt[link][u] * (cnt[link][u] - 1) for i in range(0, n): if cnt[0][i] > 0 and cnt[1][i] > 1: res += (cnt[0][i] - 1) * (cnt[1][i] - 1) print(int(res)) ```
instruction
0
90,191
13
180,382
Yes
output
1
90,191
13
180,383
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. You are given a tree (an undirected connected acyclic graph) consisting of n vertices and n - 1 edges. A number is written on each edge, each number is either 0 (let's call such edges 0-edges) or 1 (those are 1-edges). Let's call an ordered pair of vertices (x, y) (x ≠ y) valid if, while traversing the simple path from x to y, we never go through a 0-edge after going through a 1-edge. Your task is to calculate the number of valid pairs in the tree. Input The first line contains one integer n (2 ≤ n ≤ 200000) — the number of vertices in the tree. Then n - 1 lines follow, each denoting an edge of the tree. Each edge is represented by three integers x_i, y_i and c_i (1 ≤ x_i, y_i ≤ n, 0 ≤ c_i ≤ 1, x_i ≠ y_i) — the vertices connected by this edge and the number written on it, respectively. It is guaranteed that the given edges form a tree. Output Print one integer — the number of valid pairs of vertices. Example Input 7 2 1 1 3 2 0 4 2 1 5 2 0 6 7 1 7 2 1 Output 34 Note The picture corresponding to the first example: <image> Submitted Solution: ``` import sys input = sys.stdin.readline sys.setrecursionlimit(2*10**5) I = lambda : list(map(int,input().split())) n,=I() r=[[1 for i in range(n)],[1 for i in range(n)]] p=[[i for i in range(n)],[i for i in range(n)]] def find(x,c): if x!=p[c][x]: p[c][x]=find(p[c][x],c) return p[c][x] def union(a,b,c): x=find(a,c) y=find(b,c) mm=min(x,y) if x!=y: p[c][y]=p[c][x]=mm r[c][mm]+=r[c][max(x,y)] an=0 for i in range(n-1): a,b,c=I() union(a-1,b-1,c) vis=[0]*n cc=[] for i in range(n): s0=r[0][i] s1=r[1][i] if p[0][i]==i: an+=(s0-1)*s0 if p[1][i]==i: an+=(s1-1)*s1 an+=(r[1][find(i,1)]-1)*(r[0][find(i,0)]-1) print(an) ```
instruction
0
90,192
13
180,384
Yes
output
1
90,192
13
180,385
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. You are given a tree (an undirected connected acyclic graph) consisting of n vertices and n - 1 edges. A number is written on each edge, each number is either 0 (let's call such edges 0-edges) or 1 (those are 1-edges). Let's call an ordered pair of vertices (x, y) (x ≠ y) valid if, while traversing the simple path from x to y, we never go through a 0-edge after going through a 1-edge. Your task is to calculate the number of valid pairs in the tree. Input The first line contains one integer n (2 ≤ n ≤ 200000) — the number of vertices in the tree. Then n - 1 lines follow, each denoting an edge of the tree. Each edge is represented by three integers x_i, y_i and c_i (1 ≤ x_i, y_i ≤ n, 0 ≤ c_i ≤ 1, x_i ≠ y_i) — the vertices connected by this edge and the number written on it, respectively. It is guaranteed that the given edges form a tree. Output Print one integer — the number of valid pairs of vertices. Example Input 7 2 1 1 3 2 0 4 2 1 5 2 0 6 7 1 7 2 1 Output 34 Note The picture corresponding to the first example: <image> Submitted Solution: ``` class UnionFind: def __init__(self, N): self.par = [i for i in range(N)] self.rank = [1 for i in range(N)] self.rank[0] = 0 def union(self, x, y): if not self.is_same_set(x, y): par_x = self.find_par(x) par_y = self.find_par(y) if self.rank[par_x] > self.rank[par_y]: self.rank[par_x] += self.rank[par_y] self.rank[par_y] = 0 self.par[par_y] = par_x else: self.rank[par_y] += self.rank[par_x] self.rank[par_x] = 0 self.par[par_x] = par_y def find_par(self, x): if self.par[x] == x: return x self.par[x] = self.find_par(self.par[x]) return self.par[x] def is_same_set(self, x, y): return self.find_par(x) == self.find_par(y) def size(self, x): return self.rank[self.find_par(x)] # 2 unionfind, para 0 e para 1 formando 2 florestas # lista de adj # verificar todos os componentes existentes e adicionar na resposta n * (n-1) n = int(input()) adj = [[] for i in range(n+1)] uf0 = UnionFind(n+1) uf1 = UnionFind(n+1) for i in range(n-1): x, y, c = map(int, input().split()) if c == 0: uf0.union(x, y) else: uf1.union(x, y) adj[x].append(y) adj[y].append(x) uf0.find_par(x) uf1.find_par(y) resp = 0 resp += sum(map(lambda i: uf0.rank[i] * (uf0.rank[i] - 1), set(uf0.par))) resp += sum(map(lambda i: uf1.rank[i] * (uf1.rank[i] - 1), set(uf1.par))) # pra cada componente do 0-uf verificar se existe esse vertice na 1-uf e ele for conectado com alguém, se sim, multiplicar (n-1)*(m-1) sendo n o componente da 0-uf e m o componente da 1-f e adicionar na resposta #ja_visto = set() for i in range(len(uf0.par)): if uf0.rank[uf0.find_par(i)] > 1: #and not uf0.find_par(i) in ja_visto: #ja_visto.add(uf0.find_par(i)) if uf1.rank[uf1.find_par(i)] > 1: resp += (uf0.rank[uf0.find_par(i)] - 1) * (uf1.rank[uf1.find_par(i)] - 1) print(resp) ```
instruction
0
90,193
13
180,386
Yes
output
1
90,193
13
180,387
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. You are given a tree (an undirected connected acyclic graph) consisting of n vertices and n - 1 edges. A number is written on each edge, each number is either 0 (let's call such edges 0-edges) or 1 (those are 1-edges). Let's call an ordered pair of vertices (x, y) (x ≠ y) valid if, while traversing the simple path from x to y, we never go through a 0-edge after going through a 1-edge. Your task is to calculate the number of valid pairs in the tree. Input The first line contains one integer n (2 ≤ n ≤ 200000) — the number of vertices in the tree. Then n - 1 lines follow, each denoting an edge of the tree. Each edge is represented by three integers x_i, y_i and c_i (1 ≤ x_i, y_i ≤ n, 0 ≤ c_i ≤ 1, x_i ≠ y_i) — the vertices connected by this edge and the number written on it, respectively. It is guaranteed that the given edges form a tree. Output Print one integer — the number of valid pairs of vertices. Example Input 7 2 1 1 3 2 0 4 2 1 5 2 0 6 7 1 7 2 1 Output 34 Note The picture corresponding to the first example: <image> Submitted Solution: ``` import sys from collections import deque from types import GeneratorType input = lambda :sys.stdin.readline().rstrip() def bootstrap(f, stack=[]): def wrappedfunc(*args, **kwargs): if stack: return f(*args, **kwargs) else: to = f(*args, **kwargs) while True: if type(to) is GeneratorType: stack.append(to) to = next(to) else: stack.pop() if not stack: break to = stack[-1].send(to) return to return wrappedfunc n = int(input()) good_num = [0 for i in range(n + 1)] mid_num = [0 for i in range(n + 1)] tree = [[] for i in range(n + 1)] ans = [0] for i in range(n - 1): a, b, c = map(int, input().split()) tree[a].append((b, c)) tree[b].append((a, c)) root = 1 @bootstrap def dfs1(node, pa): for ch, cl in tree[node]: if ch != pa: yield dfs1(ch, node) if cl: mid_num[node] += good_num[ch] + mid_num[ch] + 1 else: good_num[node] += good_num[ch] + 1 yield 0 dfs1(root, root) @bootstrap def dfs2(node, pa, pgood, pmid): total_sub_good = good_num[node] total_sub_mid = mid_num[node] temp = ans[0] for ch, cl in tree[node]: if ch!= pa: ans[0] += good_num[ch] + mid_num[ch] if cl: ans[0] += pgood + pmid + 1 print('ch: {}, node: {}, pgood: {} , pmid: {}'.format(ch, node, pgood, pmid)) print('prev ans: {}, cur ans: {}'.format(temp, ans[0])) input() pass_down_mid = pgood + 1 pass_down_mid += total_sub_mid - mid_num[ch] yield dfs2(ch, node, 0, pass_down_mid) else: ans[0] += pgood + 1 ans[0] += total_sub_good - good_num[ch] - 1 print('ch: {}, node: {}, pgood: {} , pmid: {}'.format(ch, node, pgood, pmid)) print('prev ans: {}, cur ans: {}'.format(temp, ans[0])) input() pass_down_mid = total_sub_mid - mid_num[ch] pass_down_good = total_sub_good - good_num[ch] pass_down_good += pgood + 1 yield dfs2(ch, node,pass_down_good, pass_down_mid) yield 0 ans[0] = good_num[root] + mid_num[root] dfs2(root, root, 0,0) print(ans[0]) ```
instruction
0
90,194
13
180,388
No
output
1
90,194
13
180,389
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. You are given a tree (an undirected connected acyclic graph) consisting of n vertices and n - 1 edges. A number is written on each edge, each number is either 0 (let's call such edges 0-edges) or 1 (those are 1-edges). Let's call an ordered pair of vertices (x, y) (x ≠ y) valid if, while traversing the simple path from x to y, we never go through a 0-edge after going through a 1-edge. Your task is to calculate the number of valid pairs in the tree. Input The first line contains one integer n (2 ≤ n ≤ 200000) — the number of vertices in the tree. Then n - 1 lines follow, each denoting an edge of the tree. Each edge is represented by three integers x_i, y_i and c_i (1 ≤ x_i, y_i ≤ n, 0 ≤ c_i ≤ 1, x_i ≠ y_i) — the vertices connected by this edge and the number written on it, respectively. It is guaranteed that the given edges form a tree. Output Print one integer — the number of valid pairs of vertices. Example Input 7 2 1 1 3 2 0 4 2 1 5 2 0 6 7 1 7 2 1 Output 34 Note The picture corresponding to the first example: <image> Submitted Solution: ``` def union0(a,b): fa=find0(a) fb=find0(b) if size0[fa]>size0[fb]: size0[fa]+=size0[fb] dsu0[fb]=fa else: size0[fb]+=size0[fa] dsu0[fa]=fb def union1(a,b): fa=find1(a) fb=find1(b) if size1[fa]>size1[fb]: size1[fa]+=size1[fb] dsu1[fb]=fa else: size1[fb]+=size1[fa] dsu1[fa]=fb def find0(x): while dsu0[x]!=x: dsu0[x]=dsu0[dsu0[x]] x=dsu0[x] return x def find1(x): while dsu1[x]!=x: dsu1[x]=dsu1[dsu0[x]] x=dsu1[x] return x n=int(input()) edges=[] for i in range(n-1): a,b,c=map(int,input().split()) edges.append([c,a-1,b-1]) size0=[1]*n size1=[1]*n dsu1=[i for i in range(n)] dsu0=[i for i in range(n)] #edges.sort() ans=0 for i in range(n-1): if edges[i][0]==0: fa=find0(edges[i][1]) fb=find0(edges[i][2]) ans+=(size0[fa]*size0[fb]) union0(fa,fb) else: fa=find1(edges[i][1]) fb=find1(edges[i][2]) ans+=(size1[fa]*size1[fb]) union1(fa,fb) ans+=ans for i in range(n): f0=find0(i) f1=find1(i) ans+=((size0[f0]-1)*(size1[f1]-1)) print(ans) ```
instruction
0
90,195
13
180,390
No
output
1
90,195
13
180,391
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. You are given a tree (an undirected connected acyclic graph) consisting of n vertices and n - 1 edges. A number is written on each edge, each number is either 0 (let's call such edges 0-edges) or 1 (those are 1-edges). Let's call an ordered pair of vertices (x, y) (x ≠ y) valid if, while traversing the simple path from x to y, we never go through a 0-edge after going through a 1-edge. Your task is to calculate the number of valid pairs in the tree. Input The first line contains one integer n (2 ≤ n ≤ 200000) — the number of vertices in the tree. Then n - 1 lines follow, each denoting an edge of the tree. Each edge is represented by three integers x_i, y_i and c_i (1 ≤ x_i, y_i ≤ n, 0 ≤ c_i ≤ 1, x_i ≠ y_i) — the vertices connected by this edge and the number written on it, respectively. It is guaranteed that the given edges form a tree. Output Print one integer — the number of valid pairs of vertices. Example Input 7 2 1 1 3 2 0 4 2 1 5 2 0 6 7 1 7 2 1 Output 34 Note The picture corresponding to the first example: <image> Submitted Solution: ``` from sys import stdin, stdout n = int(stdin.readline()) g = [[] for i in range(n)] for i in range(n-1): a, b, c = map(int, stdin.readline().split()) a -= 1 b -= 1 g[a].append((b, c)) g[b].append((a, c)) dp = [[0, 0, 0] for i in range(n)] # cnt(x0), cnt(y1), cnt(0y1) def dfs(v, p): for x in g[v]: if x[0] != p: dfs(x[0], v) dp[v][x[1]] += 1 + dp[x[0]][x[1]] dfs(0, -1) def merge(v, p): for x in g[v]: if (x[0] != p): if x[1] == 0: dp[v][2] += (dp[x[0]][0] + 1) * (dp[v][1] - dp[x[0]][1]) dp[x[0]][2] += (dp[v][0] - dp[x[0]][0] - 1) * (dp[x[0]][1]) dp[x[0]][x[1]] = dp[v][x[1]] merge(x[0], v) merge(0, -1) ans = 0 for i in dp: ans += sum(i) stdout.write('%d' % ans) ```
instruction
0
90,196
13
180,392
No
output
1
90,196
13
180,393
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. You are given a tree (an undirected connected acyclic graph) consisting of n vertices and n - 1 edges. A number is written on each edge, each number is either 0 (let's call such edges 0-edges) or 1 (those are 1-edges). Let's call an ordered pair of vertices (x, y) (x ≠ y) valid if, while traversing the simple path from x to y, we never go through a 0-edge after going through a 1-edge. Your task is to calculate the number of valid pairs in the tree. Input The first line contains one integer n (2 ≤ n ≤ 200000) — the number of vertices in the tree. Then n - 1 lines follow, each denoting an edge of the tree. Each edge is represented by three integers x_i, y_i and c_i (1 ≤ x_i, y_i ≤ n, 0 ≤ c_i ≤ 1, x_i ≠ y_i) — the vertices connected by this edge and the number written on it, respectively. It is guaranteed that the given edges form a tree. Output Print one integer — the number of valid pairs of vertices. Example Input 7 2 1 1 3 2 0 4 2 1 5 2 0 6 7 1 7 2 1 Output 34 Note The picture corresponding to the first example: <image> Submitted Solution: ``` m = 200000 + 42 ker1, ker2 = [x for x in range(m)], [x for x in range(m)] cnt1, cnt2 = [1 for x in range(m)], [1 for x in range(m)] def input_t(): return [int(x) for x in input().split()] def kerik(x, p): return x if p[x] == x else kerik(p[x], p) def add(a, b, color): if color: x = kerik(a, ker1) y = kerik(b, ker1) if x != y: ker1[x] = y cnt1[y] += cnt1[x] else: x = kerik(a, ker2) y = kerik(b, ker2) if x != y: ker2[x] = y cnt2[y] += cnt2[x] n = int(input()) for _ in range(n-1): x, y, c = input_t() add(x,y, c) ans = 0 for i in range(n): if ker1[i] == i: ans += cnt1[i] * (cnt1[i] - 1) if ker2[i] == i: ans += cnt2[i] * (cnt2[i] - 1) x, y = kerik(i, ker1), kerik(i, ker2) ans += (cnt1[x] - 1) * (cnt2[y] - 1) print(ans) ```
instruction
0
90,197
13
180,394
No
output
1
90,197
13
180,395
Provide tags and a correct Python 3 solution for this coding contest problem. You are given a connected undirected weighted graph consisting of n vertices and m edges. You need to print the k-th smallest shortest path in this graph (paths from the vertex to itself are not counted, paths from i to j and from j to i are counted as one). More formally, if d is the matrix of shortest paths, where d_{i, j} is the length of the shortest path between vertices i and j (1 ≤ i < j ≤ n), then you need to print the k-th element in the sorted array consisting of all d_{i, j}, where 1 ≤ i < j ≤ n. Input The first line of the input contains three integers n, m and k (2 ≤ n ≤ 2 ⋅ 10^5, n - 1 ≤ m ≤ min\Big((n(n-1))/(2), 2 ⋅ 10^5\Big), 1 ≤ k ≤ min\Big((n(n-1))/(2), 400\Big) — the number of vertices in the graph, the number of edges in the graph and the value of k, correspondingly. Then m lines follow, each containing three integers x, y and w (1 ≤ x, y ≤ n, 1 ≤ w ≤ 10^9, x ≠ y) denoting an edge between vertices x and y of weight w. It is guaranteed that the given graph is connected (there is a path between any pair of vertices), there are no self-loops (edges connecting the vertex with itself) and multiple edges (for each pair of vertices x and y, there is at most one edge between this pair of vertices in the graph). Output Print one integer — the length of the k-th smallest shortest path in the given graph (paths from the vertex to itself are not counted, paths from i to j and from j to i are counted as one). Examples Input 6 10 5 2 5 1 5 3 9 6 2 2 1 3 1 5 1 8 6 5 10 1 6 5 6 4 6 3 6 2 3 4 5 Output 3 Input 7 15 18 2 6 3 5 7 4 6 5 4 3 6 9 6 7 7 1 6 4 7 1 6 7 2 1 4 3 2 3 2 8 5 3 6 2 5 5 3 7 9 4 1 8 2 1 1 Output 9
instruction
0
90,198
13
180,396
Tags: brute force, constructive algorithms, shortest paths, sortings Correct Solution: ``` import heapq n,m,k = map(int,input().split()) connectionList = [] for _ in range(n): connectionList.append([]) edgeList = [] for _ in range(m): x,y,w = map(int,input().split()) edgeList.append((x,y,w)) edgeList.sort(key = lambda x: x[2]) if k < m: maxDist = edgeList[min(m,k) - 1][2] else: maxDist = sum(map(lambda x: x[2],edgeList)) colorList = {} colorVertex = [] for i in range(n): colorList[i] = [i] colorVertex.append(i) for i in range(min(m,k)): x,y,w = edgeList[i] connectionList[x-1].append((y-1,w)) connectionList[y-1].append((x-1,w)) if colorVertex[x-1] != colorVertex[y-1]: if len(colorList[colorVertex[x-1]]) >= len(colorList[colorVertex[y-1]]): prevColor = colorVertex[y-1] for elem in colorList[colorVertex[y-1]]: colorVertex[elem] = colorVertex[x-1] colorList[colorVertex[x-1]].append(elem) del colorList[prevColor] else: prevColor = colorVertex[x-1] for elem in colorList[colorVertex[x-1]]: colorVertex[elem] = colorVertex[y-1] colorList[colorVertex[y-1]].append(elem) del colorList[prevColor] pathList = [] for key in colorList: vertexList = colorList[key] for mainVertex in vertexList: vertexPQueue = [] isCovered = {} distanceDic = {} for elem in vertexList: isCovered[elem] = False distanceDic[elem] = maxDist isCovered[mainVertex] = True for elem in connectionList[mainVertex]: heapq.heappush(vertexPQueue,(elem[1],elem[0])) distanceDic[elem[0]] = elem[1] while vertexPQueue: distance, curVertex = heapq.heappop(vertexPQueue) if isCovered[curVertex]: continue elif distance >= maxDist: break for elem in connectionList[curVertex]: if distance + elem[1] < distanceDic[elem[0]]: heapq.heappush(vertexPQueue,(distance + elem[1],elem[0])) distanceDic[elem[0]] = distance + elem[1] for key in distanceDic: if distanceDic[key] <= maxDist and key > mainVertex: pathList.append(distanceDic[key]) if len(pathList) > k: pathList.sort() pathList = pathList[0:k] if pathList[-1] < maxDist: maxDist = pathList[-1] pathList.sort() print(pathList[k-1]) ```
output
1
90,198
13
180,397
Provide tags and a correct Python 3 solution for this coding contest problem. You are given a connected undirected weighted graph consisting of n vertices and m edges. You need to print the k-th smallest shortest path in this graph (paths from the vertex to itself are not counted, paths from i to j and from j to i are counted as one). More formally, if d is the matrix of shortest paths, where d_{i, j} is the length of the shortest path between vertices i and j (1 ≤ i < j ≤ n), then you need to print the k-th element in the sorted array consisting of all d_{i, j}, where 1 ≤ i < j ≤ n. Input The first line of the input contains three integers n, m and k (2 ≤ n ≤ 2 ⋅ 10^5, n - 1 ≤ m ≤ min\Big((n(n-1))/(2), 2 ⋅ 10^5\Big), 1 ≤ k ≤ min\Big((n(n-1))/(2), 400\Big) — the number of vertices in the graph, the number of edges in the graph and the value of k, correspondingly. Then m lines follow, each containing three integers x, y and w (1 ≤ x, y ≤ n, 1 ≤ w ≤ 10^9, x ≠ y) denoting an edge between vertices x and y of weight w. It is guaranteed that the given graph is connected (there is a path between any pair of vertices), there are no self-loops (edges connecting the vertex with itself) and multiple edges (for each pair of vertices x and y, there is at most one edge between this pair of vertices in the graph). Output Print one integer — the length of the k-th smallest shortest path in the given graph (paths from the vertex to itself are not counted, paths from i to j and from j to i are counted as one). Examples Input 6 10 5 2 5 1 5 3 9 6 2 2 1 3 1 5 1 8 6 5 10 1 6 5 6 4 6 3 6 2 3 4 5 Output 3 Input 7 15 18 2 6 3 5 7 4 6 5 4 3 6 9 6 7 7 1 6 4 7 1 6 7 2 1 4 3 2 3 2 8 5 3 6 2 5 5 3 7 9 4 1 8 2 1 1 Output 9
instruction
0
90,199
13
180,398
Tags: brute force, constructive algorithms, shortest paths, sortings Correct Solution: ``` import sys input = sys.stdin.readline n,m,k=map(int,input().split()) EDGE=[list(map(int,input().split())) for i in range(m)] EDGE.sort(key=lambda x:x[2]) EDGE=EDGE[:k] COST_vertex=[[] for i in range(n+1)] VERLIST=[] for a,b,c in EDGE: COST_vertex[a].append((b,c)) COST_vertex[b].append((a,c)) VERLIST.append(a) VERLIST.append(b) VERLIST=sorted((set(VERLIST))) import heapq ANS=[-1<<50]*k for start in VERLIST: MINCOST=[1<<50]*(n+1) checking=[(0,start)] MINCOST[start]=0 j=0 while j<k: if not(checking): break cost,checktown=heapq.heappop(checking) if cost>=-ANS[0]: break if MINCOST[checktown]<cost: continue if cost!=0 and checktown>start: heapq.heappop(ANS) heapq.heappush(ANS,-cost) j+=1 for to,co in COST_vertex[checktown]: if MINCOST[to]>cost+co: MINCOST[to]=cost+co heapq.heappush(checking,(cost+co,to)) print(-ANS[0]) ```
output
1
90,199
13
180,399
Provide tags and a correct Python 3 solution for this coding contest problem. You are given a connected undirected weighted graph consisting of n vertices and m edges. You need to print the k-th smallest shortest path in this graph (paths from the vertex to itself are not counted, paths from i to j and from j to i are counted as one). More formally, if d is the matrix of shortest paths, where d_{i, j} is the length of the shortest path between vertices i and j (1 ≤ i < j ≤ n), then you need to print the k-th element in the sorted array consisting of all d_{i, j}, where 1 ≤ i < j ≤ n. Input The first line of the input contains three integers n, m and k (2 ≤ n ≤ 2 ⋅ 10^5, n - 1 ≤ m ≤ min\Big((n(n-1))/(2), 2 ⋅ 10^5\Big), 1 ≤ k ≤ min\Big((n(n-1))/(2), 400\Big) — the number of vertices in the graph, the number of edges in the graph and the value of k, correspondingly. Then m lines follow, each containing three integers x, y and w (1 ≤ x, y ≤ n, 1 ≤ w ≤ 10^9, x ≠ y) denoting an edge between vertices x and y of weight w. It is guaranteed that the given graph is connected (there is a path between any pair of vertices), there are no self-loops (edges connecting the vertex with itself) and multiple edges (for each pair of vertices x and y, there is at most one edge between this pair of vertices in the graph). Output Print one integer — the length of the k-th smallest shortest path in the given graph (paths from the vertex to itself are not counted, paths from i to j and from j to i are counted as one). Examples Input 6 10 5 2 5 1 5 3 9 6 2 2 1 3 1 5 1 8 6 5 10 1 6 5 6 4 6 3 6 2 3 4 5 Output 3 Input 7 15 18 2 6 3 5 7 4 6 5 4 3 6 9 6 7 7 1 6 4 7 1 6 7 2 1 4 3 2 3 2 8 5 3 6 2 5 5 3 7 9 4 1 8 2 1 1 Output 9
instruction
0
90,200
13
180,400
Tags: brute force, constructive algorithms, shortest paths, sortings Correct Solution: ``` import sys input = sys.stdin.readline n,m,k=map(int,input().split()) EDGE=[list(map(int,input().split())) for i in range(m)] EDGE.sort(key=lambda x:x[2]) EDGE=EDGE[:k] COST_vertex=[[] for i in range(n+1)] for a,b,c in EDGE: COST_vertex[a].append((b,c)) COST_vertex[b].append((a,c)) for i in range(min(m,k)): x,y,c=EDGE[i] EDGE[i]=(c,x,y) USED_SET=set() ANS=[-1<<50]*k import heapq while EDGE: c,x,y = heapq.heappop(EDGE) if (x,y) in USED_SET or c>=-ANS[0]: continue else: heapq.heappop(ANS) heapq.heappush(ANS,-c) USED_SET.add((x,y)) USED_SET.add((y,x)) for to,cost in COST_vertex[x]: if to!=y and not((y,to) in USED_SET) and c+cost<-ANS[0]: heapq.heappush(EDGE,(c+cost,y,to)) #USED_SET.add((y,to)) #USED_SET.add((to,y)) for to,cost in COST_vertex[y]: if to!=x and not((x,to) in USED_SET) and c+cost<-ANS[0]: heapq.heappush(EDGE,(c+cost,x,to)) #USED_SET.add((x,to)) #USED_SET.add((to,x)) print(-ANS[0]) ```
output
1
90,200
13
180,401
Provide tags and a correct Python 3 solution for this coding contest problem. You are given a connected undirected weighted graph consisting of n vertices and m edges. You need to print the k-th smallest shortest path in this graph (paths from the vertex to itself are not counted, paths from i to j and from j to i are counted as one). More formally, if d is the matrix of shortest paths, where d_{i, j} is the length of the shortest path between vertices i and j (1 ≤ i < j ≤ n), then you need to print the k-th element in the sorted array consisting of all d_{i, j}, where 1 ≤ i < j ≤ n. Input The first line of the input contains three integers n, m and k (2 ≤ n ≤ 2 ⋅ 10^5, n - 1 ≤ m ≤ min\Big((n(n-1))/(2), 2 ⋅ 10^5\Big), 1 ≤ k ≤ min\Big((n(n-1))/(2), 400\Big) — the number of vertices in the graph, the number of edges in the graph and the value of k, correspondingly. Then m lines follow, each containing three integers x, y and w (1 ≤ x, y ≤ n, 1 ≤ w ≤ 10^9, x ≠ y) denoting an edge between vertices x and y of weight w. It is guaranteed that the given graph is connected (there is a path between any pair of vertices), there are no self-loops (edges connecting the vertex with itself) and multiple edges (for each pair of vertices x and y, there is at most one edge between this pair of vertices in the graph). Output Print one integer — the length of the k-th smallest shortest path in the given graph (paths from the vertex to itself are not counted, paths from i to j and from j to i are counted as one). Examples Input 6 10 5 2 5 1 5 3 9 6 2 2 1 3 1 5 1 8 6 5 10 1 6 5 6 4 6 3 6 2 3 4 5 Output 3 Input 7 15 18 2 6 3 5 7 4 6 5 4 3 6 9 6 7 7 1 6 4 7 1 6 7 2 1 4 3 2 3 2 8 5 3 6 2 5 5 3 7 9 4 1 8 2 1 1 Output 9
instruction
0
90,201
13
180,402
Tags: brute force, constructive algorithms, shortest paths, sortings Correct Solution: ``` import sys,math,itertools from collections import Counter,deque,defaultdict from bisect import bisect_left,bisect_right from heapq import heappop,heappush,heapify mod = 10**9+7 INF = float('inf') def inp(): return int(sys.stdin.readline()) def inpl(): return list(map(int, sys.stdin.readline().split())) def inpl_1(): return list(map(lambda x:int(x)-1, sys.stdin.readline().split())) def inps(): return sys.stdin.readline() def inpsl(x): tmp = sys.stdin.readline(); return list(tmp[:x]) def err(x): print(x); exit() n,m,k = inpl() edges = [inpl() for _ in range(m)] edges.sort(key = lambda x:x[2]) se = set() for a,b,_ in edges[:(min(m,k))]: se.add(a-1) se.add(b-1) ls = list(se); ls.sort() ln = len(ls) d = {} for i,x in enumerate(ls): d[x] = i g = [[] for _ in range(ln)] def dijkstra(s): d = [INF]*ln; d[s] = 0 seen = [False] * ln; seen[s] = True edge = [] for x in g[s]: heappush(edge,x) while edge: mi_cost, mi_to = heappop(edge) if seen[mi_to]: continue d[mi_to] = mi_cost seen[mi_to] = True for cost,to in g[mi_to]: if seen[to]: continue heappush(edge,(cost+mi_cost,to)) return d for a,b,w in edges[:(min(m,k))]: A,B = d[a-1], d[b-1] g[A].append((w,B)) g[B].append((w,A)) dist = defaultdict(int) for i in range(ln): for x in dijkstra(i): dist[x] += 1 cnt = 0 for key in sorted(dist.keys()): if key == 0: continue cnt += dist[key]//2 if cnt >= k: err(key) ```
output
1
90,201
13
180,403
Provide tags and a correct Python 3 solution for this coding contest problem. You are given a connected undirected weighted graph consisting of n vertices and m edges. You need to print the k-th smallest shortest path in this graph (paths from the vertex to itself are not counted, paths from i to j and from j to i are counted as one). More formally, if d is the matrix of shortest paths, where d_{i, j} is the length of the shortest path between vertices i and j (1 ≤ i < j ≤ n), then you need to print the k-th element in the sorted array consisting of all d_{i, j}, where 1 ≤ i < j ≤ n. Input The first line of the input contains three integers n, m and k (2 ≤ n ≤ 2 ⋅ 10^5, n - 1 ≤ m ≤ min\Big((n(n-1))/(2), 2 ⋅ 10^5\Big), 1 ≤ k ≤ min\Big((n(n-1))/(2), 400\Big) — the number of vertices in the graph, the number of edges in the graph and the value of k, correspondingly. Then m lines follow, each containing three integers x, y and w (1 ≤ x, y ≤ n, 1 ≤ w ≤ 10^9, x ≠ y) denoting an edge between vertices x and y of weight w. It is guaranteed that the given graph is connected (there is a path between any pair of vertices), there are no self-loops (edges connecting the vertex with itself) and multiple edges (for each pair of vertices x and y, there is at most one edge between this pair of vertices in the graph). Output Print one integer — the length of the k-th smallest shortest path in the given graph (paths from the vertex to itself are not counted, paths from i to j and from j to i are counted as one). Examples Input 6 10 5 2 5 1 5 3 9 6 2 2 1 3 1 5 1 8 6 5 10 1 6 5 6 4 6 3 6 2 3 4 5 Output 3 Input 7 15 18 2 6 3 5 7 4 6 5 4 3 6 9 6 7 7 1 6 4 7 1 6 7 2 1 4 3 2 3 2 8 5 3 6 2 5 5 3 7 9 4 1 8 2 1 1 Output 9
instruction
0
90,202
13
180,404
Tags: brute force, constructive algorithms, shortest paths, sortings Correct Solution: ``` import sys input = sys.stdin.readline N, M, K = map(int, input().split()) X = [] for _ in range(M): x, y, w = map(int, input().split()) X.append([min(x,y), max(x,y), w]) X = (sorted(X, key = lambda x: x[2])+[[0, 0, 10**20] for _ in range(K)])[:K] D = {} for x, y, w in X: if x: D[x*10**6+y] = w flg = 1 while flg: flg = 0 for i in range(len(X)): x1, y1, w1 = X[i] for j in range(i+1, len(X)): x2, y2, w2 = X[j] if x1==x2: a, b = min(y1,y2), max(y1,y2) elif y1==y2: a, b = min(x1,x2), max(x1,x2) elif x1==y2: a, b = x2, y1 elif x2==y1: a, b = x1, y2 else: a, b = 0, 0 if a: if (a*10**6+b in D and w1+w2 < D[a*10**6+b]) or (a*10**6+b not in D and w1+w2 < X[-1][2]): if a*10**6+b in D: for k in range(len(X)): if X[k][0] == a and X[k][1] == b: X[k][2] = w1+w2 else: x, y, w = X.pop() if x: D.pop(x*10**6+y) X.append([a,b,w1+w2]) D[a*10**6+b] = w1+w2 X = sorted(X, key = lambda x: x[2]) flg = 1 break if flg: break print(X[-1][2]) ```
output
1
90,202
13
180,405
Provide tags and a correct Python 3 solution for this coding contest problem. You are given a connected undirected weighted graph consisting of n vertices and m edges. You need to print the k-th smallest shortest path in this graph (paths from the vertex to itself are not counted, paths from i to j and from j to i are counted as one). More formally, if d is the matrix of shortest paths, where d_{i, j} is the length of the shortest path between vertices i and j (1 ≤ i < j ≤ n), then you need to print the k-th element in the sorted array consisting of all d_{i, j}, where 1 ≤ i < j ≤ n. Input The first line of the input contains three integers n, m and k (2 ≤ n ≤ 2 ⋅ 10^5, n - 1 ≤ m ≤ min\Big((n(n-1))/(2), 2 ⋅ 10^5\Big), 1 ≤ k ≤ min\Big((n(n-1))/(2), 400\Big) — the number of vertices in the graph, the number of edges in the graph and the value of k, correspondingly. Then m lines follow, each containing three integers x, y and w (1 ≤ x, y ≤ n, 1 ≤ w ≤ 10^9, x ≠ y) denoting an edge between vertices x and y of weight w. It is guaranteed that the given graph is connected (there is a path between any pair of vertices), there are no self-loops (edges connecting the vertex with itself) and multiple edges (for each pair of vertices x and y, there is at most one edge between this pair of vertices in the graph). Output Print one integer — the length of the k-th smallest shortest path in the given graph (paths from the vertex to itself are not counted, paths from i to j and from j to i are counted as one). Examples Input 6 10 5 2 5 1 5 3 9 6 2 2 1 3 1 5 1 8 6 5 10 1 6 5 6 4 6 3 6 2 3 4 5 Output 3 Input 7 15 18 2 6 3 5 7 4 6 5 4 3 6 9 6 7 7 1 6 4 7 1 6 7 2 1 4 3 2 3 2 8 5 3 6 2 5 5 3 7 9 4 1 8 2 1 1 Output 9
instruction
0
90,203
13
180,406
Tags: brute force, constructive algorithms, shortest paths, sortings Correct Solution: ``` # i8nd5t's code modified by spider_0859 import sys,math,itertools from collections import Counter,deque,defaultdict from bisect import bisect_left,bisect_right from heapq import heappop,heappush,heapify mod = 10**9+7 INF = float('inf') def inp(): return int(sys.stdin.readline()) def inpl(): return list(map(int, sys.stdin.readline().split())) def inpl_1(): return list(map(lambda x:int(x)-1, sys.stdin.readline().split())) def inps(): return sys.stdin.readline() def inpsl(x): tmp = sys.stdin.readline(); return list(tmp[:x]) def err(x): print(x); exit() n,m,k = inpl() edges = [inpl() for _ in range(m)] edges.sort(key = lambda x:x[2]) edges = edges[:(min(m,k))] se = set() for a,b,_ in edges: se.add(a-1) se.add(b-1) ls = list(se); ls.sort() ln = len(ls) d = {} for i,x in enumerate(ls): d[x] = i g = [[] for _ in range(ln)] def dijkstra(s): d = [INF]*ln; d[s] = 0 seen = [False] * n; seen[s] = True edge = [] for x in g[s]: heappush(edge,x) while edge: mi_cost, mi_to = heappop(edge) if seen[mi_to]: continue d[mi_to] = mi_cost seen[mi_to] = True for cost,to in g[mi_to]: if d[to]<=mi_cost+cost: continue heappush(edge,(cost+mi_cost,to)) return d for a,b,w in edges: A,B = d[a-1], d[b-1] g[A].append((w,B)) g[B].append((w,A)) dist = defaultdict(int) for i in range(ln): for x in dijkstra(i): dist[x] += 1 cnt = 0 for key in sorted(dist.keys())[1:]: cnt += dist[key]//2 if cnt >= k: err(key) ```
output
1
90,203
13
180,407
Provide tags and a correct Python 3 solution for this coding contest problem. You are given a connected undirected weighted graph consisting of n vertices and m edges. You need to print the k-th smallest shortest path in this graph (paths from the vertex to itself are not counted, paths from i to j and from j to i are counted as one). More formally, if d is the matrix of shortest paths, where d_{i, j} is the length of the shortest path between vertices i and j (1 ≤ i < j ≤ n), then you need to print the k-th element in the sorted array consisting of all d_{i, j}, where 1 ≤ i < j ≤ n. Input The first line of the input contains three integers n, m and k (2 ≤ n ≤ 2 ⋅ 10^5, n - 1 ≤ m ≤ min\Big((n(n-1))/(2), 2 ⋅ 10^5\Big), 1 ≤ k ≤ min\Big((n(n-1))/(2), 400\Big) — the number of vertices in the graph, the number of edges in the graph and the value of k, correspondingly. Then m lines follow, each containing three integers x, y and w (1 ≤ x, y ≤ n, 1 ≤ w ≤ 10^9, x ≠ y) denoting an edge between vertices x and y of weight w. It is guaranteed that the given graph is connected (there is a path between any pair of vertices), there are no self-loops (edges connecting the vertex with itself) and multiple edges (for each pair of vertices x and y, there is at most one edge between this pair of vertices in the graph). Output Print one integer — the length of the k-th smallest shortest path in the given graph (paths from the vertex to itself are not counted, paths from i to j and from j to i are counted as one). Examples Input 6 10 5 2 5 1 5 3 9 6 2 2 1 3 1 5 1 8 6 5 10 1 6 5 6 4 6 3 6 2 3 4 5 Output 3 Input 7 15 18 2 6 3 5 7 4 6 5 4 3 6 9 6 7 7 1 6 4 7 1 6 7 2 1 4 3 2 3 2 8 5 3 6 2 5 5 3 7 9 4 1 8 2 1 1 Output 9
instruction
0
90,204
13
180,408
Tags: brute force, constructive algorithms, shortest paths, sortings Correct Solution: ``` import sys input = sys.stdin.readline n,m,k=map(int,input().split()) EDGE=[list(map(int,input().split())) for i in range(m)] EDGE.sort(key=lambda x:x[2]) EDGE=EDGE[:k] COST_vertex=[[] for i in range(n+1)] VERLIST=[] for a,b,c in EDGE: COST_vertex[a].append((b,c)) COST_vertex[b].append((a,c)) VERLIST.append(a) VERLIST.append(b) VERLIST=list(set(VERLIST)) import heapq ANS=[-1<<50]*k for start in VERLIST: MINCOST=[1<<50]*(n+1) checking=[(0,start)] MINCOST[start]=0 j=0 while j<k: if not(checking): break cost,checktown=heapq.heappop(checking) if cost>=-ANS[0]: break if MINCOST[checktown]<cost: continue if cost!=0 and checktown>start: heapq.heappop(ANS) heapq.heappush(ANS,-cost) j+=1 for to,co in COST_vertex[checktown]: if MINCOST[to]>cost+co: MINCOST[to]=cost+co heapq.heappush(checking,(cost+co,to)) print(-ANS[0]) ```
output
1
90,204
13
180,409
Provide tags and a correct Python 3 solution for this coding contest problem. You are given a connected undirected weighted graph consisting of n vertices and m edges. You need to print the k-th smallest shortest path in this graph (paths from the vertex to itself are not counted, paths from i to j and from j to i are counted as one). More formally, if d is the matrix of shortest paths, where d_{i, j} is the length of the shortest path between vertices i and j (1 ≤ i < j ≤ n), then you need to print the k-th element in the sorted array consisting of all d_{i, j}, where 1 ≤ i < j ≤ n. Input The first line of the input contains three integers n, m and k (2 ≤ n ≤ 2 ⋅ 10^5, n - 1 ≤ m ≤ min\Big((n(n-1))/(2), 2 ⋅ 10^5\Big), 1 ≤ k ≤ min\Big((n(n-1))/(2), 400\Big) — the number of vertices in the graph, the number of edges in the graph and the value of k, correspondingly. Then m lines follow, each containing three integers x, y and w (1 ≤ x, y ≤ n, 1 ≤ w ≤ 10^9, x ≠ y) denoting an edge between vertices x and y of weight w. It is guaranteed that the given graph is connected (there is a path between any pair of vertices), there are no self-loops (edges connecting the vertex with itself) and multiple edges (for each pair of vertices x and y, there is at most one edge between this pair of vertices in the graph). Output Print one integer — the length of the k-th smallest shortest path in the given graph (paths from the vertex to itself are not counted, paths from i to j and from j to i are counted as one). Examples Input 6 10 5 2 5 1 5 3 9 6 2 2 1 3 1 5 1 8 6 5 10 1 6 5 6 4 6 3 6 2 3 4 5 Output 3 Input 7 15 18 2 6 3 5 7 4 6 5 4 3 6 9 6 7 7 1 6 4 7 1 6 7 2 1 4 3 2 3 2 8 5 3 6 2 5 5 3 7 9 4 1 8 2 1 1 Output 9
instruction
0
90,205
13
180,410
Tags: brute force, constructive algorithms, shortest paths, sortings Correct Solution: ``` # i8nd5t's code modified by spider_0859 import sys,math,itertools from collections import Counter,deque,defaultdict from bisect import bisect_left,bisect_right from heapq import heappop,heappush,heapify mod = 10**9+7 INF = float('inf') def inp(): return int(sys.stdin.readline()) def inpl(): return list(map(int, sys.stdin.readline().split())) def inpl_1(): return list(map(lambda x:int(x)-1, sys.stdin.readline().split())) def inps(): return sys.stdin.readline() def inpsl(x): tmp = sys.stdin.readline(); return list(tmp[:x]) def err(x): print(x); exit() n,m,k = inpl() edges = [inpl() for _ in range(m)] edges.sort(key = lambda x:x[2]) edges = edges[:(min(m,k))] se = set() for a,b,_ in edges: se.add(a-1) se.add(b-1) ls = list(se); ls.sort() ln = len(ls) d = {} for i,x in enumerate(ls): d[x] = i g = [[] for _ in range(ln)] def dijkstra(s): d = [INF]*ln; d[s] = 0 edge = [] heappush(edge,(0,s)) while edge: mi_cost, mi_to = heappop(edge) if d[mi_to]<mi_cost: continue for cost,to in g[mi_to]: if d[to]<=mi_cost+cost: continue d[to] = mi_cost+cost heappush(edge,(cost+mi_cost,to)) return d for a,b,w in edges: A,B = d[a-1], d[b-1] g[A].append((w,B)) g[B].append((w,A)) dist = defaultdict(int) for i in range(ln): for x in dijkstra(i): dist[x] += 1 cnt = 0 for key in sorted(dist.keys())[1:]: cnt += dist[key]//2 if cnt >= k: err(key) ```
output
1
90,205
13
180,411
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. You are given a connected undirected weighted graph consisting of n vertices and m edges. You need to print the k-th smallest shortest path in this graph (paths from the vertex to itself are not counted, paths from i to j and from j to i are counted as one). More formally, if d is the matrix of shortest paths, where d_{i, j} is the length of the shortest path between vertices i and j (1 ≤ i < j ≤ n), then you need to print the k-th element in the sorted array consisting of all d_{i, j}, where 1 ≤ i < j ≤ n. Input The first line of the input contains three integers n, m and k (2 ≤ n ≤ 2 ⋅ 10^5, n - 1 ≤ m ≤ min\Big((n(n-1))/(2), 2 ⋅ 10^5\Big), 1 ≤ k ≤ min\Big((n(n-1))/(2), 400\Big) — the number of vertices in the graph, the number of edges in the graph and the value of k, correspondingly. Then m lines follow, each containing three integers x, y and w (1 ≤ x, y ≤ n, 1 ≤ w ≤ 10^9, x ≠ y) denoting an edge between vertices x and y of weight w. It is guaranteed that the given graph is connected (there is a path between any pair of vertices), there are no self-loops (edges connecting the vertex with itself) and multiple edges (for each pair of vertices x and y, there is at most one edge between this pair of vertices in the graph). Output Print one integer — the length of the k-th smallest shortest path in the given graph (paths from the vertex to itself are not counted, paths from i to j and from j to i are counted as one). Examples Input 6 10 5 2 5 1 5 3 9 6 2 2 1 3 1 5 1 8 6 5 10 1 6 5 6 4 6 3 6 2 3 4 5 Output 3 Input 7 15 18 2 6 3 5 7 4 6 5 4 3 6 9 6 7 7 1 6 4 7 1 6 7 2 1 4 3 2 3 2 8 5 3 6 2 5 5 3 7 9 4 1 8 2 1 1 Output 9 Submitted Solution: ``` import sys input = sys.stdin.readline N, M, K = map(int, input().split()) X = [] for _ in range(M): x, y, w = map(int, input().split()) X.append([min(x,y), max(x,y), w]) X = sorted(X, key = lambda x: x[2])[:K] X += [(0, 0, X[-1][2]) for _ in range(K - len(X))] D = {} for x, y, w in X: D[x*10**6+y] = w flg = 1 while flg: flg = 0 for i in range(min(K, M)): x1, y1, w1 = X[i] for j in range(i+1, min(K, M)): x2, y2, w2 = X[j] if x1==x2: a, b = min(y1,y2), max(y1,y2) elif y1==y2: a, b = min(x1,x2), max(x1,x2) elif x1==y2: a, b = x2, y1 elif x2==y1: a, b = x1, y2 else: a, b = 0, 0 if a: if (a*10**6+b in D and w1+w2 < D[a*10**6+b]) or (a*10**6+b not in D and w1+w2 < X[-1][2]): if a*10**6+b in D: D[a*10**6+b] = w1+w2 for k in range(len(X)): if X[k][0] == a and X[k][1] == b: X[k][2] = w1+w2 else: x, y, w = X.pop() X.append([a,b,w1+w2]) D[a*10**6+b] = w1+w2 X = sorted(X, key = lambda x: x[2]) flg = 1 print(X[-1][2]) ```
instruction
0
90,206
13
180,412
No
output
1
90,206
13
180,413
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. You are given a connected undirected weighted graph consisting of n vertices and m edges. You need to print the k-th smallest shortest path in this graph (paths from the vertex to itself are not counted, paths from i to j and from j to i are counted as one). More formally, if d is the matrix of shortest paths, where d_{i, j} is the length of the shortest path between vertices i and j (1 ≤ i < j ≤ n), then you need to print the k-th element in the sorted array consisting of all d_{i, j}, where 1 ≤ i < j ≤ n. Input The first line of the input contains three integers n, m and k (2 ≤ n ≤ 2 ⋅ 10^5, n - 1 ≤ m ≤ min\Big((n(n-1))/(2), 2 ⋅ 10^5\Big), 1 ≤ k ≤ min\Big((n(n-1))/(2), 400\Big) — the number of vertices in the graph, the number of edges in the graph and the value of k, correspondingly. Then m lines follow, each containing three integers x, y and w (1 ≤ x, y ≤ n, 1 ≤ w ≤ 10^9, x ≠ y) denoting an edge between vertices x and y of weight w. It is guaranteed that the given graph is connected (there is a path between any pair of vertices), there are no self-loops (edges connecting the vertex with itself) and multiple edges (for each pair of vertices x and y, there is at most one edge between this pair of vertices in the graph). Output Print one integer — the length of the k-th smallest shortest path in the given graph (paths from the vertex to itself are not counted, paths from i to j and from j to i are counted as one). Examples Input 6 10 5 2 5 1 5 3 9 6 2 2 1 3 1 5 1 8 6 5 10 1 6 5 6 4 6 3 6 2 3 4 5 Output 3 Input 7 15 18 2 6 3 5 7 4 6 5 4 3 6 9 6 7 7 1 6 4 7 1 6 7 2 1 4 3 2 3 2 8 5 3 6 2 5 5 3 7 9 4 1 8 2 1 1 Output 9 Submitted Solution: ``` def printMatrix(rows, columns, matrix): for i in range(rows): for j in range(columns): print(str(matrix[i][j]) + " "*(9-len(str(matrix[i][j]))), end=' | ') print() def Dijkstra(N, S, matrix): global EMPTY_PUT BESKONECHNOST = EMPTY_PUT*N valid = [True]*N weight = [BESKONECHNOST]*N weight[S] = 0 for i in range(N): min_weight = BESKONECHNOST + 1 ID_min_weight = -1 for i in range(len(weight)): if valid[i] and weight[i] < min_weight: min_weight = weight[i] ID_min_weight = i for i in range(N): if weight[ID_min_weight] + matrix[ID_min_weight][i] < weight[i]: weight[i] = weight[ID_min_weight] + matrix[ID_min_weight][i] valid[ID_min_weight] = False return weight import sys input = sys.stdin.readline EMPTY_PUT = 10**9 + 1 n, m, k= map(int, input().split()) matrix = [] for i in range(n): matrix.append([EMPTY_PUT]*n) for i in range(m): v1, v2, ves = map(int, input().split()) v1 -=1 v2 -= 1 matrix[v1][v2] = min(matrix[v1][v2], ves) matrix[v2][v1] = min(matrix[v1][v1], ves) bb = [] for i in range(n): b = Dijkstra(n, i, matrix) bb += b[i+1:] ## print(b) bb.sort() print(bb[k-1]) ##printMatrix(n, n, matrix) ```
instruction
0
90,207
13
180,414
No
output
1
90,207
13
180,415
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. You are given a connected undirected weighted graph consisting of n vertices and m edges. You need to print the k-th smallest shortest path in this graph (paths from the vertex to itself are not counted, paths from i to j and from j to i are counted as one). More formally, if d is the matrix of shortest paths, where d_{i, j} is the length of the shortest path between vertices i and j (1 ≤ i < j ≤ n), then you need to print the k-th element in the sorted array consisting of all d_{i, j}, where 1 ≤ i < j ≤ n. Input The first line of the input contains three integers n, m and k (2 ≤ n ≤ 2 ⋅ 10^5, n - 1 ≤ m ≤ min\Big((n(n-1))/(2), 2 ⋅ 10^5\Big), 1 ≤ k ≤ min\Big((n(n-1))/(2), 400\Big) — the number of vertices in the graph, the number of edges in the graph and the value of k, correspondingly. Then m lines follow, each containing three integers x, y and w (1 ≤ x, y ≤ n, 1 ≤ w ≤ 10^9, x ≠ y) denoting an edge between vertices x and y of weight w. It is guaranteed that the given graph is connected (there is a path between any pair of vertices), there are no self-loops (edges connecting the vertex with itself) and multiple edges (for each pair of vertices x and y, there is at most one edge between this pair of vertices in the graph). Output Print one integer — the length of the k-th smallest shortest path in the given graph (paths from the vertex to itself are not counted, paths from i to j and from j to i are counted as one). Examples Input 6 10 5 2 5 1 5 3 9 6 2 2 1 3 1 5 1 8 6 5 10 1 6 5 6 4 6 3 6 2 3 4 5 Output 3 Input 7 15 18 2 6 3 5 7 4 6 5 4 3 6 9 6 7 7 1 6 4 7 1 6 7 2 1 4 3 2 3 2 8 5 3 6 2 5 5 3 7 9 4 1 8 2 1 1 Output 9 Submitted Solution: ``` import sys input = sys.stdin.readline n,m,k=map(int,input().split()) EDGE=[list(map(int,input().split())) for i in range(m)] EDGE.sort(key=lambda x:x[2]) EDGE=EDGE[:k] COST_vertex=[[] for i in range(n+1)] for a,b,c in EDGE: COST_vertex[a].append((b,c)) COST_vertex[b].append((a,c)) ANS=[0] import heapq for start in range(1,n+1): MINCOST=[1<<50]*(n+1) checking=[(0,start)]# start時点のcostは0.最初はこれをチェックする. MINCOST[start]=0 for j in range(k): if not(checking): break cost,checktown=heapq.heappop(checking) if cost!=0: ANS.append(cost) if MINCOST[checktown]<cost:# 確定したものを再度チェックしなくて良い. continue for to,co in COST_vertex[checktown]: if to<=start: continue if MINCOST[to]>cost+co: MINCOST[to]=cost+co # MINCOST候補に追加 heapq.heappush(checking,(cost+co,to)) print(ANS) print(sorted(ANS)[k]) ```
instruction
0
90,208
13
180,416
No
output
1
90,208
13
180,417
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. You are given a connected undirected weighted graph consisting of n vertices and m edges. You need to print the k-th smallest shortest path in this graph (paths from the vertex to itself are not counted, paths from i to j and from j to i are counted as one). More formally, if d is the matrix of shortest paths, where d_{i, j} is the length of the shortest path between vertices i and j (1 ≤ i < j ≤ n), then you need to print the k-th element in the sorted array consisting of all d_{i, j}, where 1 ≤ i < j ≤ n. Input The first line of the input contains three integers n, m and k (2 ≤ n ≤ 2 ⋅ 10^5, n - 1 ≤ m ≤ min\Big((n(n-1))/(2), 2 ⋅ 10^5\Big), 1 ≤ k ≤ min\Big((n(n-1))/(2), 400\Big) — the number of vertices in the graph, the number of edges in the graph and the value of k, correspondingly. Then m lines follow, each containing three integers x, y and w (1 ≤ x, y ≤ n, 1 ≤ w ≤ 10^9, x ≠ y) denoting an edge between vertices x and y of weight w. It is guaranteed that the given graph is connected (there is a path between any pair of vertices), there are no self-loops (edges connecting the vertex with itself) and multiple edges (for each pair of vertices x and y, there is at most one edge between this pair of vertices in the graph). Output Print one integer — the length of the k-th smallest shortest path in the given graph (paths from the vertex to itself are not counted, paths from i to j and from j to i are counted as one). Examples Input 6 10 5 2 5 1 5 3 9 6 2 2 1 3 1 5 1 8 6 5 10 1 6 5 6 4 6 3 6 2 3 4 5 Output 3 Input 7 15 18 2 6 3 5 7 4 6 5 4 3 6 9 6 7 7 1 6 4 7 1 6 7 2 1 4 3 2 3 2 8 5 3 6 2 5 5 3 7 9 4 1 8 2 1 1 Output 9 Submitted Solution: ``` def printMatrix(rows, columns, matrix): for i in range(rows): for j in range(columns): print(str(matrix[i][j]) + " "*(9-len(str(matrix[i][j]))), end=' | ') print() def Dijkstra(N, S, matrix): global EMPTY_PUT valid = [True]*N weight = [EMPTY_PUT]*N weight[S] = 0 for i in range(N): min_weight = EMPTY_PUT + 1 ID_min_weight = -1 for i in range(len(weight)): if valid[i] and weight[i] < min_weight: min_weight = weight[i] ID_min_weight = i for i in range(N): if weight[ID_min_weight] + matrix[ID_min_weight][i] < weight[i]: weight[i] = weight[ID_min_weight] + matrix[ID_min_weight][i] valid[ID_min_weight] = False return weight import sys input = sys.stdin.readline EMPTY_PUT = 10*9 + 1 n, m, k= map(int, input().split()) matrix = [] for i in range(n): matrix.append([EMPTY_PUT]*n) for i in range(m): v1, v2, ves = map(int, input().split()) v1 -=1 v2 -= 1 if matrix[v1][v2] == EMPTY_PUT: matrix[v1][v2] = ves matrix[v2][v1] = ves else: matrix[v1][v2] = min(matrix[v1][v2], ves) matrix[v2][v1] = min(matrix[v1][v1], ves) bb = [] for i in range(n): b = Dijkstra(n, i, matrix) bb += b[i+1:] ## print(b) bb.sort() print(bb[k-1]) ##printMatrix(n, n, matrix) ```
instruction
0
90,209
13
180,418
No
output
1
90,209
13
180,419
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. Wu got hungry after an intense training session, and came to a nearby store to buy his favourite instant noodles. After Wu paid for his purchase, the cashier gave him an interesting task. You are given a bipartite graph with positive integers in all vertices of the right half. For a subset S of vertices of the left half we define N(S) as the set of all vertices of the right half adjacent to at least one vertex in S, and f(S) as the sum of all numbers in vertices of N(S). Find the greatest common divisor of f(S) for all possible non-empty subsets S (assume that GCD of empty set is 0). Wu is too tired after his training to solve this problem. Help him! Input The first line contains a single integer t (1 ≤ t ≤ 500 000) — the number of test cases in the given test set. Test case descriptions follow. The first line of each case description contains two integers n and m (1~≤~n,~m~≤~500 000) — the number of vertices in either half of the graph, and the number of edges respectively. The second line contains n integers c_i (1 ≤ c_i ≤ 10^{12}). The i-th number describes the integer in the vertex i of the right half of the graph. Each of the following m lines contains a pair of integers u_i and v_i (1 ≤ u_i, v_i ≤ n), describing an edge between the vertex u_i of the left half and the vertex v_i of the right half. It is guaranteed that the graph does not contain multiple edges. Test case descriptions are separated with empty lines. The total value of n across all test cases does not exceed 500 000, and the total value of m across all test cases does not exceed 500 000 as well. Output For each test case print a single integer — the required greatest common divisor. Example Input 3 2 4 1 1 1 1 1 2 2 1 2 2 3 4 1 1 1 1 1 1 2 2 2 2 3 4 7 36 31 96 29 1 2 1 3 1 4 2 2 2 4 3 1 4 3 Output 2 1 12 Note The greatest common divisor of a set of integers is the largest integer g such that all elements of the set are divisible by g. In the first sample case vertices of the left half and vertices of the right half are pairwise connected, and f(S) for any non-empty subset is 2, thus the greatest common divisor of these values if also equal to 2. In the second sample case the subset \{1\} in the left half is connected to vertices \{1, 2\} of the right half, with the sum of numbers equal to 2, and the subset \{1, 2\} in the left half is connected to vertices \{1, 2, 3\} of the right half, with the sum of numbers equal to 3. Thus, f(\{1\}) = 2, f(\{1, 2\}) = 3, which means that the greatest common divisor of all values of f(S) is 1. Submitted Solution: ``` import io import os from math import gcd from collections import deque, defaultdict, Counter def solve(N, M, C, edges): graph = [[] for i in range(N)] for u, v in edges: graph[u].append(v) for u in range(N): graph[u].sort() g = 0 for u in range(N): tot = 0 for v in graph[u]: tot += C[v] g = gcd(g, tot) assign = [None for i in range(N)] for u in range(N): tot = 0 for v in graph[u]: if assign[v] is None: assign[v] = u tot += C[v] g = gcd(g, tot) assign = [None for i in range(N)] for u in range(N - 1, -1, -1): tot = 0 for v in graph[u]: if assign[v] is None: assign[v] = u tot += C[v] g = gcd(g, tot) return g if __name__ == "__main__": input = io.BytesIO(os.read(0, os.fstat(0).st_size)).readline T = int(input()) for t in range(T): N, M = [int(x) for x in input().split()] C = [int(x) for x in input().split()] edges = [[int(x) - 1 for x in input().split()] for i in range(M)] burn = input() ans = solve(N, M, C, edges) print(ans) ```
instruction
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13
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No
output
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Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. Wu got hungry after an intense training session, and came to a nearby store to buy his favourite instant noodles. After Wu paid for his purchase, the cashier gave him an interesting task. You are given a bipartite graph with positive integers in all vertices of the right half. For a subset S of vertices of the left half we define N(S) as the set of all vertices of the right half adjacent to at least one vertex in S, and f(S) as the sum of all numbers in vertices of N(S). Find the greatest common divisor of f(S) for all possible non-empty subsets S (assume that GCD of empty set is 0). Wu is too tired after his training to solve this problem. Help him! Input The first line contains a single integer t (1 ≤ t ≤ 500 000) — the number of test cases in the given test set. Test case descriptions follow. The first line of each case description contains two integers n and m (1~≤~n,~m~≤~500 000) — the number of vertices in either half of the graph, and the number of edges respectively. The second line contains n integers c_i (1 ≤ c_i ≤ 10^{12}). The i-th number describes the integer in the vertex i of the right half of the graph. Each of the following m lines contains a pair of integers u_i and v_i (1 ≤ u_i, v_i ≤ n), describing an edge between the vertex u_i of the left half and the vertex v_i of the right half. It is guaranteed that the graph does not contain multiple edges. Test case descriptions are separated with empty lines. The total value of n across all test cases does not exceed 500 000, and the total value of m across all test cases does not exceed 500 000 as well. Output For each test case print a single integer — the required greatest common divisor. Example Input 3 2 4 1 1 1 1 1 2 2 1 2 2 3 4 1 1 1 1 1 1 2 2 2 2 3 4 7 36 31 96 29 1 2 1 3 1 4 2 2 2 4 3 1 4 3 Output 2 1 12 Note The greatest common divisor of a set of integers is the largest integer g such that all elements of the set are divisible by g. In the first sample case vertices of the left half and vertices of the right half are pairwise connected, and f(S) for any non-empty subset is 2, thus the greatest common divisor of these values if also equal to 2. In the second sample case the subset \{1\} in the left half is connected to vertices \{1, 2\} of the right half, with the sum of numbers equal to 2, and the subset \{1, 2\} in the left half is connected to vertices \{1, 2, 3\} of the right half, with the sum of numbers equal to 3. Thus, f(\{1\}) = 2, f(\{1, 2\}) = 3, which means that the greatest common divisor of all values of f(S) is 1. Submitted Solution: ``` import io import os from math import gcd from collections import deque, defaultdict, Counter def solve(N, M, C, edges): graph = [[] for i in range(N)] for u, v in edges: graph[u].append(v) assign = [None for i in range(N)] sums = [0 for i in range(N)] sums2 = [0 for i in range(N)] for u in range(N): for v in graph[u]: if assign[v] is None: assign[v] = u sums[u] += C[v] sums2[u] += C[v] g = 0 for v in sums: g = gcd(g, v) for v in sums2: g = gcd(g, v) return g if __name__ == "__main__": input = io.BytesIO(os.read(0, os.fstat(0).st_size)).readline T = int(input()) for t in range(T): N, M = [int(x) for x in input().split()] C = [int(x) for x in input().split()] edges = [[int(x) - 1 for x in input().split()] for i in range(M)] burn = input() ans = solve(N, M, C, edges) print(ans) ```
instruction
0
90,287
13
180,574
No
output
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90,287
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180,575
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. Wu got hungry after an intense training session, and came to a nearby store to buy his favourite instant noodles. After Wu paid for his purchase, the cashier gave him an interesting task. You are given a bipartite graph with positive integers in all vertices of the right half. For a subset S of vertices of the left half we define N(S) as the set of all vertices of the right half adjacent to at least one vertex in S, and f(S) as the sum of all numbers in vertices of N(S). Find the greatest common divisor of f(S) for all possible non-empty subsets S (assume that GCD of empty set is 0). Wu is too tired after his training to solve this problem. Help him! Input The first line contains a single integer t (1 ≤ t ≤ 500 000) — the number of test cases in the given test set. Test case descriptions follow. The first line of each case description contains two integers n and m (1~≤~n,~m~≤~500 000) — the number of vertices in either half of the graph, and the number of edges respectively. The second line contains n integers c_i (1 ≤ c_i ≤ 10^{12}). The i-th number describes the integer in the vertex i of the right half of the graph. Each of the following m lines contains a pair of integers u_i and v_i (1 ≤ u_i, v_i ≤ n), describing an edge between the vertex u_i of the left half and the vertex v_i of the right half. It is guaranteed that the graph does not contain multiple edges. Test case descriptions are separated with empty lines. The total value of n across all test cases does not exceed 500 000, and the total value of m across all test cases does not exceed 500 000 as well. Output For each test case print a single integer — the required greatest common divisor. Example Input 3 2 4 1 1 1 1 1 2 2 1 2 2 3 4 1 1 1 1 1 1 2 2 2 2 3 4 7 36 31 96 29 1 2 1 3 1 4 2 2 2 4 3 1 4 3 Output 2 1 12 Note The greatest common divisor of a set of integers is the largest integer g such that all elements of the set are divisible by g. In the first sample case vertices of the left half and vertices of the right half are pairwise connected, and f(S) for any non-empty subset is 2, thus the greatest common divisor of these values if also equal to 2. In the second sample case the subset \{1\} in the left half is connected to vertices \{1, 2\} of the right half, with the sum of numbers equal to 2, and the subset \{1, 2\} in the left half is connected to vertices \{1, 2, 3\} of the right half, with the sum of numbers equal to 3. Thus, f(\{1\}) = 2, f(\{1, 2\}) = 3, which means that the greatest common divisor of all values of f(S) is 1. Submitted Solution: ``` import io import os from math import gcd from collections import deque, defaultdict, Counter def pack(L): [a, b] = L return (a << 20) + b def unpack(i): a = i >> 20 b = i & ((1 << 20) - 1) return a, b if __name__ == "__main__": input = io.BytesIO(os.read(0, os.fstat(0).st_size)).readline out = [] T = int(input()) for t in range(T): N, M = list(map(int, input().split())) C = list(map(int, input().split())) edges = [pack(map(int, input().split())) for i in range(M)] edges.sort() assign = {} sums = defaultdict(int) # sums2 = defaultdict(int) for uv in edges: u, v = unpack(uv) if v not in assign: assign[v] = u sums[u] += C[v - 1] # sums2[u] += C[v - 1] g = 0 for v in sums.values(): g = gcd(g, v) # for v in sums2.values(): # g = gcd(g, v) out.append(str(g)) burn = input() print("\n".join(out)) ```
instruction
0
90,288
13
180,576
No
output
1
90,288
13
180,577
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. Wu got hungry after an intense training session, and came to a nearby store to buy his favourite instant noodles. After Wu paid for his purchase, the cashier gave him an interesting task. You are given a bipartite graph with positive integers in all vertices of the right half. For a subset S of vertices of the left half we define N(S) as the set of all vertices of the right half adjacent to at least one vertex in S, and f(S) as the sum of all numbers in vertices of N(S). Find the greatest common divisor of f(S) for all possible non-empty subsets S (assume that GCD of empty set is 0). Wu is too tired after his training to solve this problem. Help him! Input The first line contains a single integer t (1 ≤ t ≤ 500 000) — the number of test cases in the given test set. Test case descriptions follow. The first line of each case description contains two integers n and m (1~≤~n,~m~≤~500 000) — the number of vertices in either half of the graph, and the number of edges respectively. The second line contains n integers c_i (1 ≤ c_i ≤ 10^{12}). The i-th number describes the integer in the vertex i of the right half of the graph. Each of the following m lines contains a pair of integers u_i and v_i (1 ≤ u_i, v_i ≤ n), describing an edge between the vertex u_i of the left half and the vertex v_i of the right half. It is guaranteed that the graph does not contain multiple edges. Test case descriptions are separated with empty lines. The total value of n across all test cases does not exceed 500 000, and the total value of m across all test cases does not exceed 500 000 as well. Output For each test case print a single integer — the required greatest common divisor. Example Input 3 2 4 1 1 1 1 1 2 2 1 2 2 3 4 1 1 1 1 1 1 2 2 2 2 3 4 7 36 31 96 29 1 2 1 3 1 4 2 2 2 4 3 1 4 3 Output 2 1 12 Note The greatest common divisor of a set of integers is the largest integer g such that all elements of the set are divisible by g. In the first sample case vertices of the left half and vertices of the right half are pairwise connected, and f(S) for any non-empty subset is 2, thus the greatest common divisor of these values if also equal to 2. In the second sample case the subset \{1\} in the left half is connected to vertices \{1, 2\} of the right half, with the sum of numbers equal to 2, and the subset \{1, 2\} in the left half is connected to vertices \{1, 2, 3\} of the right half, with the sum of numbers equal to 3. Thus, f(\{1\}) = 2, f(\{1, 2\}) = 3, which means that the greatest common divisor of all values of f(S) is 1. Submitted Solution: ``` import sys input = sys.stdin.readline from collections import Counter from math import gcd t=int(input()) for tests in range(t): n,m=map(int,input().split()) C=list(map(int,input().split())) X=[[] for i in range(n+1)] for k in range(m): x,y=map(int,input().split()) X[y].append(x) #print(X) A=Counter() for i in range(n): A[tuple(sorted(X[i+1]))]+=C[i] #print(A) ANS=0 for g in A.values(): ANS=gcd(ANS,g) print(ANS) _=input() ```
instruction
0
90,289
13
180,578
No
output
1
90,289
13
180,579
Provide tags and a correct Python 3 solution for this coding contest problem. You are given a rooted tree with root in vertex 1. Each vertex is coloured in some colour. Let's call colour c dominating in the subtree of vertex v if there are no other colours that appear in the subtree of vertex v more times than colour c. So it's possible that two or more colours will be dominating in the subtree of some vertex. The subtree of vertex v is the vertex v and all other vertices that contains vertex v in each path to the root. For each vertex v find the sum of all dominating colours in the subtree of vertex v. Input The first line contains integer n (1 ≤ n ≤ 105) — the number of vertices in the tree. The second line contains n integers ci (1 ≤ ci ≤ n), ci — the colour of the i-th vertex. Each of the next n - 1 lines contains two integers xj, yj (1 ≤ xj, yj ≤ n) — the edge of the tree. The first vertex is the root of the tree. Output Print n integers — the sums of dominating colours for each vertex. Examples Input 4 1 2 3 4 1 2 2 3 2 4 Output 10 9 3 4 Input 15 1 2 3 1 2 3 3 1 1 3 2 2 1 2 3 1 2 1 3 1 4 1 14 1 15 2 5 2 6 2 7 3 8 3 9 3 10 4 11 4 12 4 13 Output 6 5 4 3 2 3 3 1 1 3 2 2 1 2 3
instruction
0
90,532
13
181,064
Tags: data structures, dfs and similar, dsu, trees Correct Solution: ``` import sys input = sys.stdin.buffer.readline class SegmentTree: def __init__(self, n, op, e): self.n = n self.op = op self.e = e self.size = 2 ** ((n - 1).bit_length()) self.node = [self.e] * (2 * self.size) def __getitem__(self, i): return self.node[i + self.size] def __setitem__(self, i, val): i += self.size self.node[i] = val while i > 1: i >>= 1 self.node[i] = self.op(self.node[i << 1], self.node[(i << 1) + 1]) def build(self, array): for i, val in enumerate(array, self.size): self.node[i] = val for i in range(self.size - 1, 0, -1): self.node[i] = self.op(self.node[i << 1], self.node[(i << 1) + 1]) def all_fold(self): return self.node[1] def fold(self, l, r): l, r = l + self.size, r + self.size vl, vr = self.e, self.e while l < r: if l & 1: vl = self.op(vl, self.node[l]) l += 1 if r & 1: r -= 1 vr = self.op(self.node[r], vr) l, r = l >> 1, r >> 1 return self.op(vl, vr) def topological_sorted(tree, root=None): n = len(tree) par = [-1] * n tp_order = [] for v in range(n): if par[v] != -1 or (root is not None and v != root): continue stack = [v] while stack: v = stack.pop() tp_order.append(v) for nxt_v in tree[v]: if nxt_v == par[v]: continue par[nxt_v] = v stack.append(nxt_v) return tp_order, par def dsu_on_tree(tree, root): n = len(tree) tp_order, par = topological_sorted(tree, root) # 有向木の構築 di_tree = [[] for i in range(n)] for v in range(n): for nxt_v in tree[v]: if nxt_v == par[v]: continue di_tree[v].append(nxt_v) # 部分木サイズの計算 sub_size = [1] * n for v in tp_order[::-1]: for nxt_v in di_tree[v]: sub_size[v] += sub_size[nxt_v] # 有向木のDFS帰りがけ順の構築 di_tree = [sorted(tr, key=lambda v: sub_size[v]) for tr in di_tree] keeps = [0] * n for v in range(n): di_tree[v] = di_tree[v][:-1][::-1] + di_tree[v][-1:] for chi_v in di_tree[v][:-1]: keeps[chi_v] = 1 tp_order, _ = topological_sorted(di_tree, root) # counts = {} def add(sub_root, val): stack = [sub_root] while stack: v = stack.pop() vals = st[colors[v]] st[colors[v]] = (vals[0] + val, vals[1]) # counts[colors[v]] = counts.get(colors[v], 0) + val for chi_v in di_tree[v]: stack.append(chi_v) for v in tp_order[::-1]: for chi_v in di_tree[v]: if keeps[chi_v] == 1: add(chi_v, 1) vals = st[colors[v]] st[colors[v]] = (vals[0] + 1, vals[1]) # counts[colors[v]] = counts.get(colors[v], 0) + 1 ans[v] = st.all_fold()[1] if keeps[v] == 1: add(v, -1) n = int(input()) colors = list(map(int, input().split())) edges = [list(map(int, input().split())) for i in range(n - 1)] tree = [[] for i in range(n)] for u, v in edges: u -= 1 v -= 1 tree[u].append(v) tree[v].append(u) def op(x, y): # x = (max, sum_val) if x[0] == y[0]: return x[0], x[1] + y[1] elif x[0] > y[0]: return x elif x[0] < y[0]: return y e = (0, 0) st = SegmentTree(10 ** 5 + 10, op, e) st.build([(0, i) for i in range(10 ** 5 + 10)]) ans = [0] * n dsu_on_tree(tree, 0) print(*ans) ```
output
1
90,532
13
181,065
Provide tags and a correct Python 3 solution for this coding contest problem. You are given a rooted tree with root in vertex 1. Each vertex is coloured in some colour. Let's call colour c dominating in the subtree of vertex v if there are no other colours that appear in the subtree of vertex v more times than colour c. So it's possible that two or more colours will be dominating in the subtree of some vertex. The subtree of vertex v is the vertex v and all other vertices that contains vertex v in each path to the root. For each vertex v find the sum of all dominating colours in the subtree of vertex v. Input The first line contains integer n (1 ≤ n ≤ 105) — the number of vertices in the tree. The second line contains n integers ci (1 ≤ ci ≤ n), ci — the colour of the i-th vertex. Each of the next n - 1 lines contains two integers xj, yj (1 ≤ xj, yj ≤ n) — the edge of the tree. The first vertex is the root of the tree. Output Print n integers — the sums of dominating colours for each vertex. Examples Input 4 1 2 3 4 1 2 2 3 2 4 Output 10 9 3 4 Input 15 1 2 3 1 2 3 3 1 1 3 2 2 1 2 3 1 2 1 3 1 4 1 14 1 15 2 5 2 6 2 7 3 8 3 9 3 10 4 11 4 12 4 13 Output 6 5 4 3 2 3 3 1 1 3 2 2 1 2 3
instruction
0
90,533
13
181,066
Tags: data structures, dfs and similar, dsu, trees Correct Solution: ``` # dsu on tree # logistics: if the problem asked to compute some value of a subtree # naive method would be for each node, compute the query value which would be O(n^2) because of doing dfs for each node # we want to reuse some information of subtree so that we do not need to recompute it # we can use concept of heavy-light decomposition which we divide the value into light nodes and heavy node # complexity proof: from collections import defaultdict as df from types import GeneratorType def bootstrap(f, stack=[]): def wrappedfunc(*args, **kwargs): if stack: return f(*args, **kwargs) else: to = f(*args, **kwargs) while True: if type(to) is GeneratorType: stack.append(to) to = next(to) else: stack.pop() if not stack: break to = stack[-1].send(to) return to return wrappedfunc timer = 0 @bootstrap def dfs(v, p): global timer tin[v] = timer ver[timer] = v timer += 1 for child in tree[v]: if child != p: yield dfs(child, v) size[v] += size[child] size[v] += 1 tout[v] = timer timer += 1 yield 0 def operation(mx, v, x): ans[cnt[color[v]]] -= color[v] cnt[color[v]] += x ans[cnt[color[v]]] += color[v] mx = max(mx, cnt[color[v]]) return mx @bootstrap def dfs1(v, pa, keep): mx = 0;mx_child = -1; big_child = -1 for child in tree[v]: if child != pa and size[child] > mx_child: mx_child = size[child] big_child = child for child in tree[v]: if child != pa and child != big_child: yield dfs1(child, v, 0) if big_child != -1: temp = yield dfs1(big_child, v, 1) mx = max(temp, mx) for child in tree[v]: if child != pa and child != big_child: for p in range(tin[child], tout[child]): # add operation #cnt[dist[ver[p]]] += 1 mx = operation(mx, ver[p], 1) #add itself mx = operation(mx,v,1) #print(v,mx) res[v - 1] = ans[mx] #put answer above if not keep: for p in range(tin[v], tout[v]): # cancel operation #cnt[dist[ver[p]]] -= 1 mx = operation(mx, ver[p], -1) yield mx if __name__ == '__main__': n = int(input().strip()) #arr = list(map(int, input().split())) color = [0] + list(map(int, input().split())) tree = df(list) for i in range(1,n): u,v = map(int, input().split()) tree[u].append(v) tree[v].append(u) #tree[arr[i - 1]].append(i + 1) #maxn = 100000 cnt = [0 for i in range(n + 1)] size = [0 for i in range(n + 1)] ver = [0 for i in range((n + 1) << 1)] tin = [0 for i in range(n + 1)] tout = [0 for i in range(n + 1)] ans = [0 for i in range(n + 1)] res = [0 for i in range(n)] #dist = [0 for i in range(n + 1)] # query = int(input().strip()) # queries = df(list) # res = df(int) # for i in range(query): # u, d = map(int, input().split()) # queries[u].append((d,i)) dfs(1, 1) dfs1(1,1,1) #res[0] = ans print(' '.join(str(i) for i in res)) ```
output
1
90,533
13
181,067
Provide tags and a correct Python 3 solution for this coding contest problem. You are given a rooted tree with root in vertex 1. Each vertex is coloured in some colour. Let's call colour c dominating in the subtree of vertex v if there are no other colours that appear in the subtree of vertex v more times than colour c. So it's possible that two or more colours will be dominating in the subtree of some vertex. The subtree of vertex v is the vertex v and all other vertices that contains vertex v in each path to the root. For each vertex v find the sum of all dominating colours in the subtree of vertex v. Input The first line contains integer n (1 ≤ n ≤ 105) — the number of vertices in the tree. The second line contains n integers ci (1 ≤ ci ≤ n), ci — the colour of the i-th vertex. Each of the next n - 1 lines contains two integers xj, yj (1 ≤ xj, yj ≤ n) — the edge of the tree. The first vertex is the root of the tree. Output Print n integers — the sums of dominating colours for each vertex. Examples Input 4 1 2 3 4 1 2 2 3 2 4 Output 10 9 3 4 Input 15 1 2 3 1 2 3 3 1 1 3 2 2 1 2 3 1 2 1 3 1 4 1 14 1 15 2 5 2 6 2 7 3 8 3 9 3 10 4 11 4 12 4 13 Output 6 5 4 3 2 3 3 1 1 3 2 2 1 2 3
instruction
0
90,534
13
181,068
Tags: data structures, dfs and similar, dsu, trees Correct Solution: ``` import sys input = sys.stdin.buffer.readline class SegmentTree: def __init__(self, n, op, e): self.n = n self.op = op self.e = e self.size = 2 ** ((n - 1).bit_length()) self.node = [self.e] * (2 * self.size) def __getitem__(self, i): return self.node[i + self.size] def __setitem__(self, i, val): i += self.size self.node[i] = val while i > 1: i >>= 1 self.node[i] = self.op(self.node[i << 1], self.node[(i << 1) + 1]) def build(self, array): for i, val in enumerate(array, self.size): self.node[i] = val for i in range(self.size - 1, 0, -1): self.node[i] = self.op(self.node[i << 1], self.node[(i << 1) + 1]) def all_fold(self): return self.node[1] def fold(self, l, r): l, r = l + self.size, r + self.size vl, vr = self.e, self.e while l < r: if l & 1: vl = self.op(vl, self.node[l]) l += 1 if r & 1: r -= 1 vr = self.op(self.node[r], vr) l, r = l >> 1, r >> 1 return self.op(vl, vr) def topological_sorted(tree, root=None): n = len(tree) par = [-1] * n tp_order = [] for v in range(n): if par[v] != -1 or (root is not None and v != root): continue stack = [v] while stack: v = stack.pop() tp_order.append(v) for nxt_v in tree[v]: if nxt_v == par[v]: continue par[nxt_v] = v stack.append(nxt_v) return tp_order, par def dsu_on_tree(tree, root): n = len(tree) tp_order, par = topological_sorted(tree, root) # 有向木の構築 di_tree = [[] for i in range(n)] for v in range(n): for nxt_v in tree[v]: if nxt_v == par[v]: continue di_tree[v].append(nxt_v) # 部分木サイズの計算 sub_size = [1] * n for v in tp_order[::-1]: for nxt_v in di_tree[v]: sub_size[v] += sub_size[nxt_v] # 有向木のDFS行きがけ順の構築 di_tree = [sorted(tr, key=lambda v: sub_size[v]) for tr in di_tree] keeps = [0] * n for v in range(n): di_tree[v] = di_tree[v][:-1][::-1] + di_tree[v][-1:] for chi_v in di_tree[v][:-1]: keeps[chi_v] = 1 tp_order, _ = topological_sorted(di_tree, root) # 加算もしくは減算の実行 # counts = {} def add(sub_root, val): stack = [sub_root] while stack: v = stack.pop() vals = st[colors[v]] st[colors[v]] = (vals[0] + val, vals[1]) # counts[colors[v]] = counts.get(colors[v], 0) + val for chi_v in di_tree[v]: stack.append(chi_v) # 有向木のDFS帰りがけ順で処理 for v in tp_order[::-1]: for chi_v in di_tree[v]: if keeps[chi_v] == 1: add(chi_v, 1) # ここでクエリを実行する vals = st[colors[v]] st[colors[v]] = (vals[0] + 1, vals[1]) # counts[colors[v]] = counts.get(colors[v], 0) + 1 ans[v] = st.all_fold()[1] if keeps[v] == 1: add(v, -1) n = int(input()) colors = list(map(int, input().split())) edges = [list(map(int, input().split())) for i in range(n - 1)] tree = [[] for i in range(n)] for u, v in edges: u -= 1 v -= 1 tree[u].append(v) tree[v].append(u) def op(x, y): # x = (max, sum_val) if x[0] == y[0]: return x[0], x[1] + y[1] elif x[0] > y[0]: return x elif x[0] < y[0]: return y e = (0, 0) st = SegmentTree(10 ** 5 + 10, op, e) st.build([(0, i) for i in range(10 ** 5 + 10)]) ans = [0] * n dsu_on_tree(tree, 0) print(*ans) ```
output
1
90,534
13
181,069
Provide tags and a correct Python 3 solution for this coding contest problem. You are given a rooted tree with root in vertex 1. Each vertex is coloured in some colour. Let's call colour c dominating in the subtree of vertex v if there are no other colours that appear in the subtree of vertex v more times than colour c. So it's possible that two or more colours will be dominating in the subtree of some vertex. The subtree of vertex v is the vertex v and all other vertices that contains vertex v in each path to the root. For each vertex v find the sum of all dominating colours in the subtree of vertex v. Input The first line contains integer n (1 ≤ n ≤ 105) — the number of vertices in the tree. The second line contains n integers ci (1 ≤ ci ≤ n), ci — the colour of the i-th vertex. Each of the next n - 1 lines contains two integers xj, yj (1 ≤ xj, yj ≤ n) — the edge of the tree. The first vertex is the root of the tree. Output Print n integers — the sums of dominating colours for each vertex. Examples Input 4 1 2 3 4 1 2 2 3 2 4 Output 10 9 3 4 Input 15 1 2 3 1 2 3 3 1 1 3 2 2 1 2 3 1 2 1 3 1 4 1 14 1 15 2 5 2 6 2 7 3 8 3 9 3 10 4 11 4 12 4 13 Output 6 5 4 3 2 3 3 1 1 3 2 2 1 2 3
instruction
0
90,535
13
181,070
Tags: data structures, dfs and similar, dsu, trees Correct Solution: ``` import sys input = sys.stdin.buffer.readline class SegmentTree: def __init__(self, n, op, e): self.n = n self.op = op self.e = e self.size = 2 ** ((n - 1).bit_length()) self.node = [self.e] * (2 * self.size) def __getitem__(self, i): return self.node[i + self.size] def __setitem__(self, i, val): i += self.size self.node[i] = val while i > 1: i >>= 1 self.node[i] = self.op(self.node[i << 1], self.node[(i << 1) + 1]) def build(self, array): for i, val in enumerate(array, self.size): self.node[i] = val for i in range(self.size - 1, 0, -1): self.node[i] = self.op(self.node[i << 1], self.node[(i << 1) + 1]) def all_fold(self): return self.node[1] def fold(self, l, r): l, r = l + self.size, r + self.size vl, vr = self.e, self.e while l < r: if l & 1: vl = self.op(vl, self.node[l]) l += 1 if r & 1: r -= 1 vr = self.op(self.node[r], vr) l, r = l >> 1, r >> 1 return self.op(vl, vr) def topological_sorted(tree, root=None): n = len(tree) par = [-1] * n tp_order = [] for v in range(n): if par[v] != -1 or (root is not None and v != root): continue stack = [v] while stack: v = stack.pop() tp_order.append(v) for nxt_v in tree[v]: if nxt_v == par[v]: continue par[nxt_v] = v stack.append(nxt_v) return tp_order, par def dsu_on_tree(tree, root, add, sub, query): n = len(tree) tp_order, par = topological_sorted(tree, root) # 1.有向木の構築 di_tree = [[] for i in range(n)] for v in range(n): for nxt_v in tree[v]: if nxt_v == par[v]: continue di_tree[v].append(nxt_v) # 2.部分木サイズの計算 sub_size = [1] * n for v in tp_order[::-1]: for nxt_v in di_tree[v]: sub_size[v] += sub_size[nxt_v] # 3.有向木のDFS行きがけ順の構築 di_tree = [sorted(tr, key=lambda v: sub_size[v]) for tr in di_tree] keeps = [0] * n for v in range(n): di_tree[v] = di_tree[v][:-1][::-1] + di_tree[v][-1:] for chi_v in di_tree[v][-1:]: keeps[chi_v] = 1 tp_order, _ = topological_sorted(di_tree, root) # 部分木からの加算もしくは減算 def calc(sub_root, is_add): stack = [sub_root] while stack: v = stack.pop() add(v) if is_add else sub(v) for chi_v in di_tree[v]: stack.append(chi_v) # 4.有向木のDFS帰りがけ順で頂点vの部分木クエリを処理 for v in tp_order[::-1]: for chi_v in di_tree[v]: if keeps[chi_v] == 0: calc(chi_v, 1) add(v) # ここでクエリを実行する query(v) if keeps[v] == 0: calc(v, 0) n = int(input()) colors = list(map(int, input().split())) edges = [list(map(int, input().split())) for i in range(n - 1)] tree = [[] for i in range(n)] for u, v in edges: u -= 1 v -= 1 tree[u].append(v) tree[v].append(u) def op(x, y): # x = (max, sum_val) if x[0] == y[0]: return x[0], x[1] + y[1] elif x[0] > y[0]: return x elif x[0] < y[0]: return y e = (0, 0) st = SegmentTree(10 ** 5 + 10, op, e) st.build([(0, i) for i in range(10 ** 5 + 10)]) def add(v): max_, sum_ = st[colors[v]] st[colors[v]] = (max_ + 1, sum_) def sub(v): max_, sum_ = st[colors[v]] st[colors[v]] = (max_ - 1, sum_) ans = [0] * n def query(v): max_, sum_ = st.all_fold() ans[v] = sum_ dsu_on_tree(tree, 0, add, sub, query) print(*ans) ```
output
1
90,535
13
181,071
Provide tags and a correct Python 3 solution for this coding contest problem. You are given a rooted tree with root in vertex 1. Each vertex is coloured in some colour. Let's call colour c dominating in the subtree of vertex v if there are no other colours that appear in the subtree of vertex v more times than colour c. So it's possible that two or more colours will be dominating in the subtree of some vertex. The subtree of vertex v is the vertex v and all other vertices that contains vertex v in each path to the root. For each vertex v find the sum of all dominating colours in the subtree of vertex v. Input The first line contains integer n (1 ≤ n ≤ 105) — the number of vertices in the tree. The second line contains n integers ci (1 ≤ ci ≤ n), ci — the colour of the i-th vertex. Each of the next n - 1 lines contains two integers xj, yj (1 ≤ xj, yj ≤ n) — the edge of the tree. The first vertex is the root of the tree. Output Print n integers — the sums of dominating colours for each vertex. Examples Input 4 1 2 3 4 1 2 2 3 2 4 Output 10 9 3 4 Input 15 1 2 3 1 2 3 3 1 1 3 2 2 1 2 3 1 2 1 3 1 4 1 14 1 15 2 5 2 6 2 7 3 8 3 9 3 10 4 11 4 12 4 13 Output 6 5 4 3 2 3 3 1 1 3 2 2 1 2 3
instruction
0
90,536
13
181,072
Tags: data structures, dfs and similar, dsu, trees Correct Solution: ``` from collections import defaultdict class SumDefaultdict(defaultdict): def __init__(self, *args, **kwargs) -> None: super().__init__(int, *args, **kwargs) self.mx = max(self.values()) self.mx_sum = sum(c for c, v in self.items() if v == self.mx) def sumadd(self, map): for bb, val in map.items(): if val > 0: self[bb] += val if self[bb] > self.mx: self.mx = self[bb] self.mx_sum = bb elif self[bb] == self.mx: self.mx_sum += bb def go(): n = int(input()) c = list(map(int, input().split())) edges = [[] for _ in range(n)] for _ in range(n - 1): a, b = map(lambda x: int(x) - 1, input().split()) edges[a].append(b) edges[b].append(a) depth = [0] + [None] * (n - 1) parent = [None] * n que = [0] index = 0 while index < len(que): curr = que[index] for b in edges[curr]: if depth[b] is None: depth[b] = depth[curr] + 1 parent[b] = curr que.append(b) index += 1 order = sorted(((depth[i], i) for i in range(n)), reverse=True) cols = [SumDefaultdict({c[i]: 1}) for i in range(n)] answer = [0] * n for d, i in order: children = sorted([cols[b] for b in edges[i] if depth[b] > d], key=len, reverse=True) if children: for j in range(1, len(children)): children[0].sumadd(children[j]) children[0].sumadd({c[i]: 1}) cols[i] = children[0] # max_val = max(cols[i].values()) answer[i] = cols[i].mx_sum print(' '.join(map(str, answer))) go() ```
output
1
90,536
13
181,073
Provide tags and a correct Python 3 solution for this coding contest problem. You are given a rooted tree with root in vertex 1. Each vertex is coloured in some colour. Let's call colour c dominating in the subtree of vertex v if there are no other colours that appear in the subtree of vertex v more times than colour c. So it's possible that two or more colours will be dominating in the subtree of some vertex. The subtree of vertex v is the vertex v and all other vertices that contains vertex v in each path to the root. For each vertex v find the sum of all dominating colours in the subtree of vertex v. Input The first line contains integer n (1 ≤ n ≤ 105) — the number of vertices in the tree. The second line contains n integers ci (1 ≤ ci ≤ n), ci — the colour of the i-th vertex. Each of the next n - 1 lines contains two integers xj, yj (1 ≤ xj, yj ≤ n) — the edge of the tree. The first vertex is the root of the tree. Output Print n integers — the sums of dominating colours for each vertex. Examples Input 4 1 2 3 4 1 2 2 3 2 4 Output 10 9 3 4 Input 15 1 2 3 1 2 3 3 1 1 3 2 2 1 2 3 1 2 1 3 1 4 1 14 1 15 2 5 2 6 2 7 3 8 3 9 3 10 4 11 4 12 4 13 Output 6 5 4 3 2 3 3 1 1 3 2 2 1 2 3
instruction
0
90,537
13
181,074
Tags: data structures, dfs and similar, dsu, trees Correct Solution: ``` import sys from collections import Counter n = int(input()) color = list(map(int, input().split())) adj = [[] for _ in range(n)] for _ in range(n-1): u, v = map(int, sys.stdin.readline().split()) u -= 1 v -= 1 adj[u].append(v) adj[v].append(u) count = [Counter() for _ in range(n)] max_cnt = [0]*n dp = [0]*n stack = [0] par = [-1]*n order = [] while stack: v = stack.pop() order.append(v) for d in adj[v]: if d != par[v]: stack.append(d) par[d] = v for v in reversed(order): child = [i for i in adj[v] if i != par[v]] child.sort(key=lambda v: -len(count[v])) if child: dp[v] = dp[child[0]] max_cnt[v] = max_cnt[child[0]] count[v] = count[child[0]] for d in child[1:]: for k, val in count[d].items(): count[v][k] += val if count[v][k] > max_cnt[v]: dp[v] = k max_cnt[v] = count[v][k] elif count[v][k] == max_cnt[v]: dp[v] += k count[v][color[v]] += 1 if count[v][color[v]] > max_cnt[v]: dp[v] = color[v] max_cnt[v] = count[v][color[v]] elif count[v][color[v]] == max_cnt[v]: dp[v] += color[v] if par[v] != -1: stack.append(par[v]) print(*dp) ```
output
1
90,537
13
181,075
Provide tags and a correct Python 3 solution for this coding contest problem. You are given a rooted tree with root in vertex 1. Each vertex is coloured in some colour. Let's call colour c dominating in the subtree of vertex v if there are no other colours that appear in the subtree of vertex v more times than colour c. So it's possible that two or more colours will be dominating in the subtree of some vertex. The subtree of vertex v is the vertex v and all other vertices that contains vertex v in each path to the root. For each vertex v find the sum of all dominating colours in the subtree of vertex v. Input The first line contains integer n (1 ≤ n ≤ 105) — the number of vertices in the tree. The second line contains n integers ci (1 ≤ ci ≤ n), ci — the colour of the i-th vertex. Each of the next n - 1 lines contains two integers xj, yj (1 ≤ xj, yj ≤ n) — the edge of the tree. The first vertex is the root of the tree. Output Print n integers — the sums of dominating colours for each vertex. Examples Input 4 1 2 3 4 1 2 2 3 2 4 Output 10 9 3 4 Input 15 1 2 3 1 2 3 3 1 1 3 2 2 1 2 3 1 2 1 3 1 4 1 14 1 15 2 5 2 6 2 7 3 8 3 9 3 10 4 11 4 12 4 13 Output 6 5 4 3 2 3 3 1 1 3 2 2 1 2 3
instruction
0
90,538
13
181,076
Tags: data structures, dfs and similar, dsu, trees Correct Solution: ``` def main(): import sys from collections import deque input = sys.stdin.readline N = int(input()) color = list(map(int, input().split())) color.insert(0, 0) adj = [[] for _ in range(N+1)] for _ in range(N-1): a, b = map(int, input().split()) adj[a].append(b) adj[b].append(a) que = deque() que.append(1) seen = [-1] * (N+1) seen[1] = 0 par = [0] * (N+1) child = [[] for _ in range(N+1)] seq = [] while que: v = que.popleft() seq.append(v) for u in adj[v]: if seen[u] == -1: seen[u] = seen[v] + 1 par[u] = v child[v].append(u) que.append(u) seq.reverse() cnt = [{color[i]: 1} for i in range(N+1)] cnt_size = [1] * (N+1) dom_num = [1] * (N+1) ans = [color[i] for i in range(N+1)] for v in seq: big = cnt[v] size_big = cnt_size[v] for u in child[v]: small = cnt[u] size_small = cnt_size[u] if size_big < size_small: small, big = big, small dom_num[v] = dom_num[u] ans[v] = ans[u] size_big += size_small for c in small: if c not in big: big[c] = small[c] else: big[c] += small[c] cnt_size[v] += small[c] if big[c] > dom_num[v]: dom_num[v] = big[c] ans[v] = c elif big[c] == dom_num[v]: ans[v] += c cnt_size[v] = size_big cnt[v] = big print(*ans[1:]) #print(child) #print(cnt) #print(cnt_size) if __name__ == '__main__': main() ```
output
1
90,538
13
181,077
Provide tags and a correct Python 3 solution for this coding contest problem. You are given a rooted tree with root in vertex 1. Each vertex is coloured in some colour. Let's call colour c dominating in the subtree of vertex v if there are no other colours that appear in the subtree of vertex v more times than colour c. So it's possible that two or more colours will be dominating in the subtree of some vertex. The subtree of vertex v is the vertex v and all other vertices that contains vertex v in each path to the root. For each vertex v find the sum of all dominating colours in the subtree of vertex v. Input The first line contains integer n (1 ≤ n ≤ 105) — the number of vertices in the tree. The second line contains n integers ci (1 ≤ ci ≤ n), ci — the colour of the i-th vertex. Each of the next n - 1 lines contains two integers xj, yj (1 ≤ xj, yj ≤ n) — the edge of the tree. The first vertex is the root of the tree. Output Print n integers — the sums of dominating colours for each vertex. Examples Input 4 1 2 3 4 1 2 2 3 2 4 Output 10 9 3 4 Input 15 1 2 3 1 2 3 3 1 1 3 2 2 1 2 3 1 2 1 3 1 4 1 14 1 15 2 5 2 6 2 7 3 8 3 9 3 10 4 11 4 12 4 13 Output 6 5 4 3 2 3 3 1 1 3 2 2 1 2 3
instruction
0
90,539
13
181,078
Tags: data structures, dfs and similar, dsu, trees Correct Solution: ``` import os import sys from io import BytesIO, IOBase _str = str BUFSIZE = 8192 def str(x=b''): return x if type(x) is bytes else _str(x).encode() class FastIO(IOBase): newlines = 0 def __init__(self, file): self._fd = file.fileno() self.buffer = BytesIO() self.writable = 'x' in file.mode or 'r' not in file.mode self.write = self.buffer.write if self.writable else None def read(self): while True: b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE)) if not b: break ptr = self.buffer.tell() self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr) self.newlines = 0 return self.buffer.read() def readline(self): while self.newlines == 0: b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE)) self.newlines = b.count(b'\n') + (not b) ptr = self.buffer.tell() self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr) self.newlines -= 1 return self.buffer.readline() def flush(self): if self.writable: os.write(self._fd, self.buffer.getvalue()) self.buffer.truncate(0), self.buffer.seek(0) class IOWrapper(IOBase): def __init__(self, file): self.buffer = FastIO(file) self.flush = self.buffer.flush self.writable = self.buffer.writable self.write = lambda s: self.buffer.write(s.encode('ascii')) self.read = lambda: self.buffer.read().decode('ascii') self.readline = lambda: self.buffer.readline().decode('ascii') def inp(): return sys.stdin.readline().rstrip() def mpint(): return map(int, inp().split(' ')) def itg(): return int(inp()) # ############################## import # from ACgenerator.Y_Testing import get_code def tree_bfs(tree, flat=True, start=0) -> list: stack = [start] result = [] while stack: new_stack = [] if flat: result.extend(stack) else: result.append(stack) for node in stack: new_stack.extend(tree[node]) stack = new_stack return result def to_tree(graph, root=0): """ graph: [{child, ...}, ...] (undirected) :return directed graph that parent -> children """ stack = [[root]] while stack: if not stack[-1]: del stack[-1] continue parent = stack[-1].pop() for child in graph[parent]: graph[child].discard(parent) stack.append(list(graph[parent])) def tree_postorder(tree, flat=True, root=0): """ children -> parent """ return tree_bfs(tree, flat, root)[::-1] # ############################## main from collections import defaultdict class Counter: def __init__(self, c): self.ans = c self.c_t = defaultdict(lambda: 0) self.mx = self.c_t[c] = 1 self.t_c = defaultdict(set) self.t_c[1] = {c} def merge(self, other): for c, t in other.c_t.items(): self.add(c, t) def add(self, c, t): old_t = self.c_t[c] self.c_t[c] = new_t = old_t + t self.t_c[old_t].discard(c) self.t_c[new_t].add(c) if new_t == self.mx: self.ans += c elif new_t > self.mx: self.mx = new_t self.ans = c def __len__(self): return len(self.c_t) def __repr__(self): return _str(self.ans) def solve(): n = itg() ans = list(map(Counter, mpint())) tree = [set() for _ in range(n)] for _ in range(n - 1): a, b = mpint() a -= 1 b -= 1 tree[a].add(b) tree[b].add(a) to_tree(tree) for parent in tree_postorder(tree): for child in tree[parent]: child_ans = ans[child].ans if len(ans[parent]) < len(ans[child]): ans[parent], ans[child] = ans[child], ans[parent] ans[parent].merge(ans[child]) ans[child] = child_ans return ans def main(): # solve() print(*solve()) # for _ in range(itg()): # print(solve()) # print("YES" if solve() else "NO") # print("yes" if solve() else "no") DEBUG = 0 URL = 'https://codeforces.com/contest/600/problem/E' if __name__ == '__main__': if DEBUG == 1: import requests # ImportError: cannot import name 'md5' from 'sys' (unknown location) from ACgenerator.Y_Test_Case_Runner import TestCaseRunner runner = TestCaseRunner(main, URL) inp = runner.input_stream print = runner.output_stream runner.checking() elif DEBUG == 2: main() else: sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout) main() # Please check! ```
output
1
90,539
13
181,079
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. You are given a rooted tree with root in vertex 1. Each vertex is coloured in some colour. Let's call colour c dominating in the subtree of vertex v if there are no other colours that appear in the subtree of vertex v more times than colour c. So it's possible that two or more colours will be dominating in the subtree of some vertex. The subtree of vertex v is the vertex v and all other vertices that contains vertex v in each path to the root. For each vertex v find the sum of all dominating colours in the subtree of vertex v. Input The first line contains integer n (1 ≤ n ≤ 105) — the number of vertices in the tree. The second line contains n integers ci (1 ≤ ci ≤ n), ci — the colour of the i-th vertex. Each of the next n - 1 lines contains two integers xj, yj (1 ≤ xj, yj ≤ n) — the edge of the tree. The first vertex is the root of the tree. Output Print n integers — the sums of dominating colours for each vertex. Examples Input 4 1 2 3 4 1 2 2 3 2 4 Output 10 9 3 4 Input 15 1 2 3 1 2 3 3 1 1 3 2 2 1 2 3 1 2 1 3 1 4 1 14 1 15 2 5 2 6 2 7 3 8 3 9 3 10 4 11 4 12 4 13 Output 6 5 4 3 2 3 3 1 1 3 2 2 1 2 3 Submitted Solution: ``` import sys import collections import random input = sys.stdin.readline d = collections.defaultdict(list) n = int(input()) col = [int(i) for i in input().split() ] for _ in range(n-1): a, b = map(int, input().split() ) d[a-1].append(b-1) d[b-1].append(a-1) def dfs(parent, node, que, cnt, m): makenew = False for i in d[node]: if i == parent: continue if makenew: q1, c1 = {}, {} dfs(node, i, q1, c1, [0]) for key in c1: #key = color if key in cnt: que[cnt[key]] -= key cnt[key] += c1[key] else: cnt[key] = c1[key] if cnt[key] not in que: que[cnt[key]] = 0 que[cnt[key]] += key if m[0] < cnt[key]: m[0] = cnt[key] continue dfs(node, i, que, cnt, m) makenew = True # leaves finish here: if len(que) == 0: que[1] = col[node] cnt[col[node]] = 1 m[0] = 1 return # nodes accumulating: if col[node] in cnt: que[cnt[col[node]]] -= col[node] cnt[col[node]] += 1 if cnt[col[node]] not in que: que[cnt[col[node]]] = 0 que[cnt[col[node]]] += col[node] if m[0] < cnt[col[node]]: m[0] = cnt[col[node]] else: cnt[col[node]] = 1 if 1 not in que: que[1] = 0 que[1] += col[node] col[node] = que[ m[0] ] return try: dfs(-1, 0, {}, {}, [0]) except RuntimeError as e: print(e) print( " ".join(list(map(str, col )))) ```
instruction
0
90,540
13
181,080
No
output
1
90,540
13
181,081
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. You are given a rooted tree with root in vertex 1. Each vertex is coloured in some colour. Let's call colour c dominating in the subtree of vertex v if there are no other colours that appear in the subtree of vertex v more times than colour c. So it's possible that two or more colours will be dominating in the subtree of some vertex. The subtree of vertex v is the vertex v and all other vertices that contains vertex v in each path to the root. For each vertex v find the sum of all dominating colours in the subtree of vertex v. Input The first line contains integer n (1 ≤ n ≤ 105) — the number of vertices in the tree. The second line contains n integers ci (1 ≤ ci ≤ n), ci — the colour of the i-th vertex. Each of the next n - 1 lines contains two integers xj, yj (1 ≤ xj, yj ≤ n) — the edge of the tree. The first vertex is the root of the tree. Output Print n integers — the sums of dominating colours for each vertex. Examples Input 4 1 2 3 4 1 2 2 3 2 4 Output 10 9 3 4 Input 15 1 2 3 1 2 3 3 1 1 3 2 2 1 2 3 1 2 1 3 1 4 1 14 1 15 2 5 2 6 2 7 3 8 3 9 3 10 4 11 4 12 4 13 Output 6 5 4 3 2 3 3 1 1 3 2 2 1 2 3 Submitted Solution: ``` #600E cin = lambda:map(int,input().split()) n=int(input()) color=list(cin()) D=dict() for i in range(n-1): a,b=cin() if a not in D: D[a]={b} else: D[a].add(b) colorres=[0]*n def myadd(x, y): return list(map(lambda a, b: a + b, x, y)) def maxsum(l): maxc=max(l) res=0 for i in range(n+1): if l[i]==maxc: res+=i return(res) def myf(v): if v not in D: colorres[v-1]=color[v-1] l=[0]*(n+1) l[color[v-1]]=1 return l else: l=[0]*(n+1) l[color[v-1]]+=1 for vc in D[v]: l=myadd(l,myf(vc)) colorres[v-1]=maxsum(l) return(l) myf(1) print(' '.join(map(str, colorres ))) ```
instruction
0
90,541
13
181,082
No
output
1
90,541
13
181,083
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. You are given a rooted tree with root in vertex 1. Each vertex is coloured in some colour. Let's call colour c dominating in the subtree of vertex v if there are no other colours that appear in the subtree of vertex v more times than colour c. So it's possible that two or more colours will be dominating in the subtree of some vertex. The subtree of vertex v is the vertex v and all other vertices that contains vertex v in each path to the root. For each vertex v find the sum of all dominating colours in the subtree of vertex v. Input The first line contains integer n (1 ≤ n ≤ 105) — the number of vertices in the tree. The second line contains n integers ci (1 ≤ ci ≤ n), ci — the colour of the i-th vertex. Each of the next n - 1 lines contains two integers xj, yj (1 ≤ xj, yj ≤ n) — the edge of the tree. The first vertex is the root of the tree. Output Print n integers — the sums of dominating colours for each vertex. Examples Input 4 1 2 3 4 1 2 2 3 2 4 Output 10 9 3 4 Input 15 1 2 3 1 2 3 3 1 1 3 2 2 1 2 3 1 2 1 3 1 4 1 14 1 15 2 5 2 6 2 7 3 8 3 9 3 10 4 11 4 12 4 13 Output 6 5 4 3 2 3 3 1 1 3 2 2 1 2 3 Submitted Solution: ``` import sys sys.setrecursionlimit(100000) input = sys.stdin.readline n = int(input()) vertexes = list(map(int, input().split())) tree_map = {} for i in range(n - 1): a, b = map(int, input().split()) if a in tree_map: tree_map[a].append(b) else: tree_map[a] = [b] freq = [-1 for i in range(n)] result = [-1 for i in range(n)] def sum_dict(a, b): for key in a: if key in b: b[key] += a[key] else: b[key] = a[key] return b def solve(node): if result[node - 1] != -1: return freq[node - 1] if node in tree_map: frequency = {vertexes[node - 1]: 1} for next_node in tree_map[node]: f = solve(next_node) frequency = sum_dict(f, frequency) n = max(frequency.values()) s = 0 for i in frequency: if frequency[i] == n: s += i result[node - 1] = s freq[node - 1] = frequency return frequency else: freq[node - 1] = {vertexes[node - 1]: 1} result[node - 1] = vertexes[node - 1] return freq[node - 1] solve(1) for i, n in enumerate(result): if n == -1: result[i] = vertexes[i] print(*result) ```
instruction
0
90,542
13
181,084
No
output
1
90,542
13
181,085
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. You are given a rooted tree with root in vertex 1. Each vertex is coloured in some colour. Let's call colour c dominating in the subtree of vertex v if there are no other colours that appear in the subtree of vertex v more times than colour c. So it's possible that two or more colours will be dominating in the subtree of some vertex. The subtree of vertex v is the vertex v and all other vertices that contains vertex v in each path to the root. For each vertex v find the sum of all dominating colours in the subtree of vertex v. Input The first line contains integer n (1 ≤ n ≤ 105) — the number of vertices in the tree. The second line contains n integers ci (1 ≤ ci ≤ n), ci — the colour of the i-th vertex. Each of the next n - 1 lines contains two integers xj, yj (1 ≤ xj, yj ≤ n) — the edge of the tree. The first vertex is the root of the tree. Output Print n integers — the sums of dominating colours for each vertex. Examples Input 4 1 2 3 4 1 2 2 3 2 4 Output 10 9 3 4 Input 15 1 2 3 1 2 3 3 1 1 3 2 2 1 2 3 1 2 1 3 1 4 1 14 1 15 2 5 2 6 2 7 3 8 3 9 3 10 4 11 4 12 4 13 Output 6 5 4 3 2 3 3 1 1 3 2 2 1 2 3 Submitted Solution: ``` import sys sys.setrecursionlimit(100000) input = sys.stdin.readline n = int(input()) vertexes = list(map(int, input().split())) tree_map = {} for i in range(n - 1): a, b = map(int, input().split()) if a in tree_map: tree_map[a].append(b) else: tree_map[a] = [b] freq = [-1 for i in range(n)] result = [-1 for i in range(n)] def sum_dict(a, b): for key in a: if key in b: b[key] += a[key] else: b[key] = a[key] return b def solve(node): if result[node - 1] != -1: return freq[node - 1] if node in tree_map: frequency = {vertexes[node - 1]: 1} for next_node in tree_map[node]: f = solve(next_node) frequency = sum_dict(f, frequency) n = max(frequency.values()) s = 0 for i in frequency: if frequency[i] == n: s += i result[node - 1] = s freq[node - 1] = frequency return frequency else: freq[node - 1] = {vertexes[node - 1]: 1} result[node - 1] = vertexes[node - 1] return freq[node - 1] solve(1) if n == 4 or n == 15: print(*result) else: print(tree_map[1]) ```
instruction
0
90,543
13
181,086
No
output
1
90,543
13
181,087