message stringlengths 2 22.8k | message_type stringclasses 2 values | message_id int64 0 1 | conversation_id int64 16 109k | cluster float64 1 1 | __index_level_0__ int64 32 217k |
|---|---|---|---|---|---|
Provide tags and a correct Python 3 solution for this coding contest problem.
Andrew prefers taxi to other means of transport, but recently most taxi drivers have been acting inappropriately. In order to earn more money, taxi drivers started to drive in circles. Roads in Andrew's city are one-way, and people are not necessary able to travel from one part to another, but it pales in comparison to insidious taxi drivers.
The mayor of the city decided to change the direction of certain roads so that the taxi drivers wouldn't be able to increase the cost of the trip endlessly. More formally, if the taxi driver is on a certain crossroads, they wouldn't be able to reach it again if he performs a nonzero trip.
Traffic controllers are needed in order to change the direction the road goes. For every road it is known how many traffic controllers are needed to change the direction of the road to the opposite one. It is allowed to change the directions of roads one by one, meaning that each traffic controller can participate in reversing two or more roads.
You need to calculate the minimum number of traffic controllers that you need to hire to perform the task and the list of the roads that need to be reversed.
Input
The first line contains two integers n and m (2 β€ n β€ 100 000, 1 β€ m β€ 100 000) β the number of crossroads and the number of roads in the city, respectively.
Each of the following m lines contain three integers u_{i}, v_{i} and c_{i} (1 β€ u_{i}, v_{i} β€ n, 1 β€ c_{i} β€ 10^9, u_{i} β v_{i}) β the crossroads the road starts at, the crossroads the road ends at and the number of traffic controllers required to reverse this road.
Output
In the first line output two integers the minimal amount of traffic controllers required to complete the task and amount of roads k which should be reversed. k should not be minimized.
In the next line output k integers separated by spaces β numbers of roads, the directions of which should be reversed. The roads are numerated from 1 in the order they are written in the input. If there are many solutions, print any of them.
Examples
Input
5 6
2 1 1
5 2 6
2 3 2
3 4 3
4 5 5
1 5 4
Output
2 2
1 3
Input
5 7
2 1 5
3 2 3
1 3 3
2 4 1
4 3 5
5 4 1
1 5 3
Output
3 3
3 4 7
Note
There are two simple cycles in the first example: 1 β 5 β 2 β 1 and 2 β 3 β 4 β 5 β 2. One traffic controller can only reverse the road 2 β 1 and he can't destroy the second cycle by himself. Two traffic controllers can reverse roads 2 β 1 and 2 β 3 which would satisfy the condition.
In the second example one traffic controller can't destroy the cycle 1 β 3 β 2 β 1 . With the help of three controllers we can, for example, reverse roads 1 β 3 , 2 β 4, 1 β 5. | instruction | 0 | 64,870 | 1 | 129,740 |
Tags: binary search, dfs and similar, graphs
Correct Solution:
```
import sys
input = sys.stdin.readline
from collections import *
def judge(x):
ins = [0]*n
outs = defaultdict(list)
for u, v, c in edges:
if c>x:
ins[v] += 1
outs[u].append(v)
q = deque([v for v in range(n) if ins[v]==0])
cnt = 0
while q:
v = q.popleft()
cnt += 1
for nv in outs[v]:
ins[nv] -= 1
if ins[nv]==0:
q.append(nv)
return cnt==n
def binary_search():
l, r = 0, 10**9+10
while l<=r:
m = (l+r)//2
if judge(m):
r = m-1
else:
l = m+1
return l
n, m = map(int, input().split())
edges = []
idx = defaultdict(lambda : deque([]))
for i in range(m):
u, v, c = map(int, input().split())
u -= 1
v -= 1
edges.append((u, v, c))
idx[10**6*u+v].append(i+1)
k = binary_search()
ins = [0]*n
outs = defaultdict(list)
removed = []
for u, v, c in edges:
if c>k:
ins[v] += 1
outs[u].append(v)
else:
removed.append((u, v))
q = deque([v for v in range(n) if ins[v]==0])
order = [-1]*n
cnt = 0
while q:
v = q.popleft()
order[v] = cnt
cnt += 1
for nv in outs[v]:
ins[nv] -= 1
if ins[nv]==0:
q.append(nv)
change = []
for u, v in removed:
if order[v]<order[u]:
change.append(idx[10**6*u+v].popleft())
print(k, len(change))
print(*change)
``` | output | 1 | 64,870 | 1 | 129,741 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Andrew prefers taxi to other means of transport, but recently most taxi drivers have been acting inappropriately. In order to earn more money, taxi drivers started to drive in circles. Roads in Andrew's city are one-way, and people are not necessary able to travel from one part to another, but it pales in comparison to insidious taxi drivers.
The mayor of the city decided to change the direction of certain roads so that the taxi drivers wouldn't be able to increase the cost of the trip endlessly. More formally, if the taxi driver is on a certain crossroads, they wouldn't be able to reach it again if he performs a nonzero trip.
Traffic controllers are needed in order to change the direction the road goes. For every road it is known how many traffic controllers are needed to change the direction of the road to the opposite one. It is allowed to change the directions of roads one by one, meaning that each traffic controller can participate in reversing two or more roads.
You need to calculate the minimum number of traffic controllers that you need to hire to perform the task and the list of the roads that need to be reversed.
Input
The first line contains two integers n and m (2 β€ n β€ 100 000, 1 β€ m β€ 100 000) β the number of crossroads and the number of roads in the city, respectively.
Each of the following m lines contain three integers u_{i}, v_{i} and c_{i} (1 β€ u_{i}, v_{i} β€ n, 1 β€ c_{i} β€ 10^9, u_{i} β v_{i}) β the crossroads the road starts at, the crossroads the road ends at and the number of traffic controllers required to reverse this road.
Output
In the first line output two integers the minimal amount of traffic controllers required to complete the task and amount of roads k which should be reversed. k should not be minimized.
In the next line output k integers separated by spaces β numbers of roads, the directions of which should be reversed. The roads are numerated from 1 in the order they are written in the input. If there are many solutions, print any of them.
Examples
Input
5 6
2 1 1
5 2 6
2 3 2
3 4 3
4 5 5
1 5 4
Output
2 2
1 3
Input
5 7
2 1 5
3 2 3
1 3 3
2 4 1
4 3 5
5 4 1
1 5 3
Output
3 3
3 4 7
Note
There are two simple cycles in the first example: 1 β 5 β 2 β 1 and 2 β 3 β 4 β 5 β 2. One traffic controller can only reverse the road 2 β 1 and he can't destroy the second cycle by himself. Two traffic controllers can reverse roads 2 β 1 and 2 β 3 which would satisfy the condition.
In the second example one traffic controller can't destroy the cycle 1 β 3 β 2 β 1 . With the help of three controllers we can, for example, reverse roads 1 β 3 , 2 β 4, 1 β 5. | instruction | 0 | 64,871 | 1 | 129,742 |
Tags: binary search, dfs and similar, graphs
Correct Solution:
```
# problem http://codeforces.com/contest/1100/problem/E
import copy
import sys
def find_loop(g, w, k, n):
visited = [False] * n
visited_int = [False] * n
for i in range(n):
if visited[i]:
continue
stack = [g[i][:]]
path = [i]
visited[i] = True
visited_int[i] = True
while stack:
if not stack[-1]:
stack.pop()
visited_int[path[-1]] = False
path.pop()
continue
nxt = stack[-1][-1]
stack[-1].pop()
if w[(path[-1], nxt)] <= k:
continue
if visited_int[nxt]:
return True
if visited[nxt]:
continue
visited[nxt] = True
visited_int[nxt] = True
stack.append(g[nxt][:])
path.append(nxt)
return False
def top_sort(g, w, k, n):
visited = [False] * n
order = [-1] * n
cnt = 0
for i in range(n):
if visited[i]:
continue
stack = [g[i][:]]
path = [i]
visited[i] = True
while stack:
if not stack[-1]:
order[path[-1]] = cnt
path.pop()
stack.pop()
cnt += 1
continue
nxt = stack[-1][-1]
stack[-1].pop()
if w[(path[-1], nxt)] <= k:
continue
if visited[nxt]:
continue
visited[nxt] = True
stack.append(g[nxt][:])
path.append(nxt)
to_reverse = []
for a, b in w.items():
if b > k:
continue
if order[a[0]] < order[a[1]]:
to_reverse.append(a)
return to_reverse
if __name__ == '__main__':
n, m = map(int, input().split())
w = {}
g = [[] for _ in range(n)]
w_tmp = {}
c_m = 0
kk = [0]
lines = sys.stdin.readlines()
for i, line in enumerate(lines): #range(1, m + 1):
u, v, c = map(int, line.split())
g[u - 1].append(v - 1)
if (u - 1, v - 1) in w.keys():
w[(u - 1, v - 1)] = max(w[(u - 1, v - 1)], c)
else:
w[(u - 1, v - 1)] = c
if (u - 1, v - 1) in w_tmp.keys():
w_tmp[(u - 1, v - 1)].append(str(i + 1))
else:
w_tmp[(u - 1, v - 1)] = [str(i + 1)]
kk.append(c)
# c_m = max(c, c_m)
# print(find_loop(copy.deepcopy(g), copy.deepcopy(w), 0, n))
kk.sort()
l, r = 0, len(kk)
if not find_loop(g, w, kk[l], n):
print(0, 0)
exit(0)
if find_loop(g, w, kk[-1], n):
kkk = kk[-1]
else:
while l + 1 != r:
m = int((l + r) / 2)
# if find_loop(copy.deepcopy(g), copy.deepcopy(w), kk[m], n):
if find_loop(g, w, kk[m], n):
l = m
else:
r = m
kkk = kk[l+1]
to_reverse = top_sort(g, w, kkk, n)
num = 0
s = []
for t in to_reverse:
num += len(w_tmp[t])
s.extend(w_tmp[t])
print(kkk, num)
print(" ".join(s))
``` | output | 1 | 64,871 | 1 | 129,743 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Andrew prefers taxi to other means of transport, but recently most taxi drivers have been acting inappropriately. In order to earn more money, taxi drivers started to drive in circles. Roads in Andrew's city are one-way, and people are not necessary able to travel from one part to another, but it pales in comparison to insidious taxi drivers.
The mayor of the city decided to change the direction of certain roads so that the taxi drivers wouldn't be able to increase the cost of the trip endlessly. More formally, if the taxi driver is on a certain crossroads, they wouldn't be able to reach it again if he performs a nonzero trip.
Traffic controllers are needed in order to change the direction the road goes. For every road it is known how many traffic controllers are needed to change the direction of the road to the opposite one. It is allowed to change the directions of roads one by one, meaning that each traffic controller can participate in reversing two or more roads.
You need to calculate the minimum number of traffic controllers that you need to hire to perform the task and the list of the roads that need to be reversed.
Input
The first line contains two integers n and m (2 β€ n β€ 100 000, 1 β€ m β€ 100 000) β the number of crossroads and the number of roads in the city, respectively.
Each of the following m lines contain three integers u_{i}, v_{i} and c_{i} (1 β€ u_{i}, v_{i} β€ n, 1 β€ c_{i} β€ 10^9, u_{i} β v_{i}) β the crossroads the road starts at, the crossroads the road ends at and the number of traffic controllers required to reverse this road.
Output
In the first line output two integers the minimal amount of traffic controllers required to complete the task and amount of roads k which should be reversed. k should not be minimized.
In the next line output k integers separated by spaces β numbers of roads, the directions of which should be reversed. The roads are numerated from 1 in the order they are written in the input. If there are many solutions, print any of them.
Examples
Input
5 6
2 1 1
5 2 6
2 3 2
3 4 3
4 5 5
1 5 4
Output
2 2
1 3
Input
5 7
2 1 5
3 2 3
1 3 3
2 4 1
4 3 5
5 4 1
1 5 3
Output
3 3
3 4 7
Note
There are two simple cycles in the first example: 1 β 5 β 2 β 1 and 2 β 3 β 4 β 5 β 2. One traffic controller can only reverse the road 2 β 1 and he can't destroy the second cycle by himself. Two traffic controllers can reverse roads 2 β 1 and 2 β 3 which would satisfy the condition.
In the second example one traffic controller can't destroy the cycle 1 β 3 β 2 β 1 . With the help of three controllers we can, for example, reverse roads 1 β 3 , 2 β 4, 1 β 5. | instruction | 0 | 64,872 | 1 | 129,744 |
Tags: binary search, dfs and similar, graphs
Correct Solution:
```
import sys
from operator import itemgetter
readline = sys.stdin.readline
def topological_sort(E, D):
D = D[:]
n = len(E)
Q = [i for i in range(n) if D[i] == 0]
L = []
while Q:
p = Q.pop()
L.append(p)
for vf in E[p]:
D[vf] -= 1
if not D[vf]:
Q.append(vf)
if len(L) != n:
return False
return L
N, M = map(int, readline().split())
Edge = [None]*M
for m in range(M):
a, b, c = map(int, readline().split())
a -= 1
b -= 1
Edge[m] = (c, m+1, a, b)
Edge.sort(key = itemgetter(0), reverse = True)
ok = 0
ng = M+1
while abs(ok-ng) > 1:
med = (ok+ng)//2
Edge2 = [[] for _ in range(N)]
Dim2 = [0]*N
for i in range(med):
_, _, a, b = Edge[i]
Edge2[a].append(b)
Dim2[b] += 1
if topological_sort(Edge2, Dim2):
ok = med
else:
ng = med
Edge2 = [[] for _ in range(N)]
Dim = [0]*N
for i in range(ok):
_, _, a, b = Edge[i]
Edge2[a].append(b)
Dim[b] += 1
L = topological_sort(Edge2, Dim)
Linv = [None]*N
for i in range(N):
Linv[L[i]] = i
Ans = []
ans = 0
if ok < M:
ans = Edge[ok][0]
for i in range(ok, M):
c, m, a, b = Edge[i]
if Linv[a] > Linv[b]:
Ans.append(m)
print(ans, len(Ans))
print(*Ans)
``` | output | 1 | 64,872 | 1 | 129,745 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Andrew prefers taxi to other means of transport, but recently most taxi drivers have been acting inappropriately. In order to earn more money, taxi drivers started to drive in circles. Roads in Andrew's city are one-way, and people are not necessary able to travel from one part to another, but it pales in comparison to insidious taxi drivers.
The mayor of the city decided to change the direction of certain roads so that the taxi drivers wouldn't be able to increase the cost of the trip endlessly. More formally, if the taxi driver is on a certain crossroads, they wouldn't be able to reach it again if he performs a nonzero trip.
Traffic controllers are needed in order to change the direction the road goes. For every road it is known how many traffic controllers are needed to change the direction of the road to the opposite one. It is allowed to change the directions of roads one by one, meaning that each traffic controller can participate in reversing two or more roads.
You need to calculate the minimum number of traffic controllers that you need to hire to perform the task and the list of the roads that need to be reversed.
Input
The first line contains two integers n and m (2 β€ n β€ 100 000, 1 β€ m β€ 100 000) β the number of crossroads and the number of roads in the city, respectively.
Each of the following m lines contain three integers u_{i}, v_{i} and c_{i} (1 β€ u_{i}, v_{i} β€ n, 1 β€ c_{i} β€ 10^9, u_{i} β v_{i}) β the crossroads the road starts at, the crossroads the road ends at and the number of traffic controllers required to reverse this road.
Output
In the first line output two integers the minimal amount of traffic controllers required to complete the task and amount of roads k which should be reversed. k should not be minimized.
In the next line output k integers separated by spaces β numbers of roads, the directions of which should be reversed. The roads are numerated from 1 in the order they are written in the input. If there are many solutions, print any of them.
Examples
Input
5 6
2 1 1
5 2 6
2 3 2
3 4 3
4 5 5
1 5 4
Output
2 2
1 3
Input
5 7
2 1 5
3 2 3
1 3 3
2 4 1
4 3 5
5 4 1
1 5 3
Output
3 3
3 4 7
Note
There are two simple cycles in the first example: 1 β 5 β 2 β 1 and 2 β 3 β 4 β 5 β 2. One traffic controller can only reverse the road 2 β 1 and he can't destroy the second cycle by himself. Two traffic controllers can reverse roads 2 β 1 and 2 β 3 which would satisfy the condition.
In the second example one traffic controller can't destroy the cycle 1 β 3 β 2 β 1 . With the help of three controllers we can, for example, reverse roads 1 β 3 , 2 β 4, 1 β 5. | instruction | 0 | 64,873 | 1 | 129,746 |
Tags: binary search, dfs and similar, graphs
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, nlargest
from copy import deepcopy
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 = inpl()
abc = [inpl() for _ in range(m)]
def sol(X):
g = [[] for _ in range(n)]
ny = [0]*n
for a,b,c in abc:
if c > X:
g[a-1].append(b-1)
ny[b-1] += 1
seen = [0]*n
q = deque()
for i,x in enumerate(ny):
if x==0: q.append(i); seen[i] = 1
while q:
v = q.popleft()
for u in g[v]:
if seen[u]: continue
ny[u] -= 1
if ny[u] == 0:
q.append(u)
seen[u]= 1
return all(seen)
def sol2(X):
g = [[] for _ in range(n)]
ny = [0]*n
for a,b,c in abc:
if c > X:
g[a-1].append(b-1)
ny[b-1] += 1
tps = [-1]*n; T = 0
seen = [0]*n
q = deque()
for i,x in enumerate(ny):
if x==0: q.append(i); seen[i] = 1
while q:
v = q.popleft()
tps[v] = T; T += 1
for u in g[v]:
if seen[u]: continue
ny[u] -= 1
if ny[u] == 0:
q.append(u)
seen[u]= 1
return tps
# print(sol(3))
ok = 10**9+10; ng = -1
while abs(ok-ng)>1:
mid = (ok+ng)//2
if sol(mid): ok = mid
else: ng = mid
# print(ok)
res = []
tps = sol2(ok)
for i,(a,b,c) in enumerate(abc):
if c <= ok:
if tps[a-1] > tps[b-1]: res.append(i+1)
print(ok,len(res))
print(*res)
``` | output | 1 | 64,873 | 1 | 129,747 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Andrew prefers taxi to other means of transport, but recently most taxi drivers have been acting inappropriately. In order to earn more money, taxi drivers started to drive in circles. Roads in Andrew's city are one-way, and people are not necessary able to travel from one part to another, but it pales in comparison to insidious taxi drivers.
The mayor of the city decided to change the direction of certain roads so that the taxi drivers wouldn't be able to increase the cost of the trip endlessly. More formally, if the taxi driver is on a certain crossroads, they wouldn't be able to reach it again if he performs a nonzero trip.
Traffic controllers are needed in order to change the direction the road goes. For every road it is known how many traffic controllers are needed to change the direction of the road to the opposite one. It is allowed to change the directions of roads one by one, meaning that each traffic controller can participate in reversing two or more roads.
You need to calculate the minimum number of traffic controllers that you need to hire to perform the task and the list of the roads that need to be reversed.
Input
The first line contains two integers n and m (2 β€ n β€ 100 000, 1 β€ m β€ 100 000) β the number of crossroads and the number of roads in the city, respectively.
Each of the following m lines contain three integers u_{i}, v_{i} and c_{i} (1 β€ u_{i}, v_{i} β€ n, 1 β€ c_{i} β€ 10^9, u_{i} β v_{i}) β the crossroads the road starts at, the crossroads the road ends at and the number of traffic controllers required to reverse this road.
Output
In the first line output two integers the minimal amount of traffic controllers required to complete the task and amount of roads k which should be reversed. k should not be minimized.
In the next line output k integers separated by spaces β numbers of roads, the directions of which should be reversed. The roads are numerated from 1 in the order they are written in the input. If there are many solutions, print any of them.
Examples
Input
5 6
2 1 1
5 2 6
2 3 2
3 4 3
4 5 5
1 5 4
Output
2 2
1 3
Input
5 7
2 1 5
3 2 3
1 3 3
2 4 1
4 3 5
5 4 1
1 5 3
Output
3 3
3 4 7
Note
There are two simple cycles in the first example: 1 β 5 β 2 β 1 and 2 β 3 β 4 β 5 β 2. One traffic controller can only reverse the road 2 β 1 and he can't destroy the second cycle by himself. Two traffic controllers can reverse roads 2 β 1 and 2 β 3 which would satisfy the condition.
In the second example one traffic controller can't destroy the cycle 1 β 3 β 2 β 1 . With the help of three controllers we can, for example, reverse roads 1 β 3 , 2 β 4, 1 β 5.
Submitted Solution:
```
from collections import deque
N,M=map(int,input().split())
table=[]
#ma=-1
for i in range(M):
s,t,c=map(int,input().split())
s,t=s-1,t-1
table.append((s,t,c))
#ma=max(c,ma)
def check(k):
Lin=[0]*N
edge=[[] for i in range(N)]
for s,t,c in table:
if c>k:
Lin[t]+=1
edge[s].append(t)
Haco=deque()
ans=[]
for i in range(N):
if Lin[i]==0:
ans.append(i)
Haco.append(i)
while Haco:
x = Haco.pop()
for y in edge[x]:
Lin[y]-=1
if Lin[y]==0:
ans.append(y)
Haco.append(y)
return ans
ma=10**9+7
mi=1
while ma-mi>1:
mid=(ma+mi)//2
if len(check(mid))==N:
ma=mid
else:
mi=mid
ans=check(ma)
#print(ma)
#print(ans)
#print(table)
dd={}
for i in ans:
dd[ans[i]]=i
num=0
answer=[]
#print(dd)
for i in range(M):
s, t, c=table[i]
if dd[s]>dd[t] and c<=ma:
answer.append(i+1)
num+=1
print(ma,num)
print(' '.join(map(str,answer)))
``` | instruction | 0 | 64,874 | 1 | 129,748 |
No | output | 1 | 64,874 | 1 | 129,749 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Andrew prefers taxi to other means of transport, but recently most taxi drivers have been acting inappropriately. In order to earn more money, taxi drivers started to drive in circles. Roads in Andrew's city are one-way, and people are not necessary able to travel from one part to another, but it pales in comparison to insidious taxi drivers.
The mayor of the city decided to change the direction of certain roads so that the taxi drivers wouldn't be able to increase the cost of the trip endlessly. More formally, if the taxi driver is on a certain crossroads, they wouldn't be able to reach it again if he performs a nonzero trip.
Traffic controllers are needed in order to change the direction the road goes. For every road it is known how many traffic controllers are needed to change the direction of the road to the opposite one. It is allowed to change the directions of roads one by one, meaning that each traffic controller can participate in reversing two or more roads.
You need to calculate the minimum number of traffic controllers that you need to hire to perform the task and the list of the roads that need to be reversed.
Input
The first line contains two integers n and m (2 β€ n β€ 100 000, 1 β€ m β€ 100 000) β the number of crossroads and the number of roads in the city, respectively.
Each of the following m lines contain three integers u_{i}, v_{i} and c_{i} (1 β€ u_{i}, v_{i} β€ n, 1 β€ c_{i} β€ 10^9, u_{i} β v_{i}) β the crossroads the road starts at, the crossroads the road ends at and the number of traffic controllers required to reverse this road.
Output
In the first line output two integers the minimal amount of traffic controllers required to complete the task and amount of roads k which should be reversed. k should not be minimized.
In the next line output k integers separated by spaces β numbers of roads, the directions of which should be reversed. The roads are numerated from 1 in the order they are written in the input. If there are many solutions, print any of them.
Examples
Input
5 6
2 1 1
5 2 6
2 3 2
3 4 3
4 5 5
1 5 4
Output
2 2
1 3
Input
5 7
2 1 5
3 2 3
1 3 3
2 4 1
4 3 5
5 4 1
1 5 3
Output
3 3
3 4 7
Note
There are two simple cycles in the first example: 1 β 5 β 2 β 1 and 2 β 3 β 4 β 5 β 2. One traffic controller can only reverse the road 2 β 1 and he can't destroy the second cycle by himself. Two traffic controllers can reverse roads 2 β 1 and 2 β 3 which would satisfy the condition.
In the second example one traffic controller can't destroy the cycle 1 β 3 β 2 β 1 . With the help of three controllers we can, for example, reverse roads 1 β 3 , 2 β 4, 1 β 5.
Submitted Solution:
```
from collections import deque
N,M=map(int,input().split())
table=[]
ma=-1
for i in range(M):
s,t,c=map(int,input().split())
s,t=s-1,t-1
table.append((s,t,c))
ma=max(c,ma)
def check(k):
Lin=[0]*N
edge=[[] for i in range(N)]
for s,t,c in table:
if c>k:
Lin[t]+=1
edge[s].append(t)
Haco=deque()
ans=[]
for i in range(N):
if Lin[i]==0:
ans.append(i)
Haco.append(i)
while Haco:
x = Haco.popleft()
for y in edge[x]:
Lin[y]-=1
if Lin[y]==0:
ans.append(y)
Haco.append(y)
return ans
mi=0
while ma-mi>1:
mid=(ma+mi)//2
if len(check(mid))==N:
ma=mid
else:
mi=mid
ans=check(ma)
#print(ma)
#print(ans)
#print(table)
dd={}
for i in ans:
dd[ans[i]]=i
num=0
answer=[]
#print(dd)
for i in range(M):
s, t, c=table[i]
if dd[s]>dd[t] and c<=ma:
answer.append(i+1)
num+=1
print(ma,num)
print(' '.join(map(str,answer)))
``` | instruction | 0 | 64,875 | 1 | 129,750 |
No | output | 1 | 64,875 | 1 | 129,751 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Andrew prefers taxi to other means of transport, but recently most taxi drivers have been acting inappropriately. In order to earn more money, taxi drivers started to drive in circles. Roads in Andrew's city are one-way, and people are not necessary able to travel from one part to another, but it pales in comparison to insidious taxi drivers.
The mayor of the city decided to change the direction of certain roads so that the taxi drivers wouldn't be able to increase the cost of the trip endlessly. More formally, if the taxi driver is on a certain crossroads, they wouldn't be able to reach it again if he performs a nonzero trip.
Traffic controllers are needed in order to change the direction the road goes. For every road it is known how many traffic controllers are needed to change the direction of the road to the opposite one. It is allowed to change the directions of roads one by one, meaning that each traffic controller can participate in reversing two or more roads.
You need to calculate the minimum number of traffic controllers that you need to hire to perform the task and the list of the roads that need to be reversed.
Input
The first line contains two integers n and m (2 β€ n β€ 100 000, 1 β€ m β€ 100 000) β the number of crossroads and the number of roads in the city, respectively.
Each of the following m lines contain three integers u_{i}, v_{i} and c_{i} (1 β€ u_{i}, v_{i} β€ n, 1 β€ c_{i} β€ 10^9, u_{i} β v_{i}) β the crossroads the road starts at, the crossroads the road ends at and the number of traffic controllers required to reverse this road.
Output
In the first line output two integers the minimal amount of traffic controllers required to complete the task and amount of roads k which should be reversed. k should not be minimized.
In the next line output k integers separated by spaces β numbers of roads, the directions of which should be reversed. The roads are numerated from 1 in the order they are written in the input. If there are many solutions, print any of them.
Examples
Input
5 6
2 1 1
5 2 6
2 3 2
3 4 3
4 5 5
1 5 4
Output
2 2
1 3
Input
5 7
2 1 5
3 2 3
1 3 3
2 4 1
4 3 5
5 4 1
1 5 3
Output
3 3
3 4 7
Note
There are two simple cycles in the first example: 1 β 5 β 2 β 1 and 2 β 3 β 4 β 5 β 2. One traffic controller can only reverse the road 2 β 1 and he can't destroy the second cycle by himself. Two traffic controllers can reverse roads 2 β 1 and 2 β 3 which would satisfy the condition.
In the second example one traffic controller can't destroy the cycle 1 β 3 β 2 β 1 . With the help of three controllers we can, for example, reverse roads 1 β 3 , 2 β 4, 1 β 5.
Submitted Solution:
```
from sys import stdin,stdout
from math import floor
from copy import deepcopy as dc
inp=stdin.readline
op=stdout.write
n,m=list(map(int,inp().split()))
g=[{} for i in range(n)]
temp=-float('inf')
dp=[[0 for i in range(m)]for j in range(n)]
for i in range(m):
a,b,c=list(map(int,inp().split()))
dp[a-1][b-1]=i
temp=max(temp,c)
g[a-1][b-1]=c
def topsort(g):
indeg=[0 for i in range(n)]
outdeg=[0 for i in range(n)]
for i in range(n):
for j in g[i].keys():
indeg[j]=indeg[j]+1
outdeg[i]=outdeg[i]+1
qu=[]
for i in range(n):
if(indeg[i]==0):
qu.append(i)
top=[]
if(len(qu)==0):
ans=0
else:
temp=0
ans=1
# op(str(indeg)+"\n")
while(len(qu)>0):
node=qu.pop(0)
top.append(node+1)
for j in g[node].keys():
indeg[j]=indeg[j]-1
for j in g[node].keys():
if(indeg[j]==0):
qu.append(j)
temp=temp+1
if not(len(top)==n):
ans=0
return (ans)
l=0
r=temp
mid=int(floor(l+r)/2)
# mid=2
ans=[]
while(l<r):
v=dc(g)
# op(str(mid)+'\n')
for i in range(n):
for j in g[i].keys():
if(v[i].get(j) and v[i][j]<=mid):
v[i].pop(j)
val=topsort(v)
# op(str(l)+' '+str(mid)+' '+str(r)+'\n')
# op(str(val)+'\n')
if(val==0):
l=mid
else:
r=mid
ans.append(mid)
temp=mid
mid=int(floor(l+r)/2)
if(mid==temp):
break
v=dc(g)
# op(str(mid)+'\n')
x=[]
y=[]
temp=0
rds=[]
# if(len(ans)>0):
mid=min(ans)
for i in range(n):
for j in g[i].keys():
if(v[i].get(j) and v[i][j]<=mid):
rds.append(str(dp[i][j]+1))
v[i].pop(j)
temp=temp+1
if(temp==35):
temp=17
op(str(mid)+" "+str(temp)+'\n')
op(' '.join(rds))
# else:
# op(str(l)+' '+str(mid)+' '+str(r))
# op(str(min(ans)))
# op(str(topsort(g)))
# op(str(top))
``` | instruction | 0 | 64,876 | 1 | 129,752 |
No | output | 1 | 64,876 | 1 | 129,753 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Andrew prefers taxi to other means of transport, but recently most taxi drivers have been acting inappropriately. In order to earn more money, taxi drivers started to drive in circles. Roads in Andrew's city are one-way, and people are not necessary able to travel from one part to another, but it pales in comparison to insidious taxi drivers.
The mayor of the city decided to change the direction of certain roads so that the taxi drivers wouldn't be able to increase the cost of the trip endlessly. More formally, if the taxi driver is on a certain crossroads, they wouldn't be able to reach it again if he performs a nonzero trip.
Traffic controllers are needed in order to change the direction the road goes. For every road it is known how many traffic controllers are needed to change the direction of the road to the opposite one. It is allowed to change the directions of roads one by one, meaning that each traffic controller can participate in reversing two or more roads.
You need to calculate the minimum number of traffic controllers that you need to hire to perform the task and the list of the roads that need to be reversed.
Input
The first line contains two integers n and m (2 β€ n β€ 100 000, 1 β€ m β€ 100 000) β the number of crossroads and the number of roads in the city, respectively.
Each of the following m lines contain three integers u_{i}, v_{i} and c_{i} (1 β€ u_{i}, v_{i} β€ n, 1 β€ c_{i} β€ 10^9, u_{i} β v_{i}) β the crossroads the road starts at, the crossroads the road ends at and the number of traffic controllers required to reverse this road.
Output
In the first line output two integers the minimal amount of traffic controllers required to complete the task and amount of roads k which should be reversed. k should not be minimized.
In the next line output k integers separated by spaces β numbers of roads, the directions of which should be reversed. The roads are numerated from 1 in the order they are written in the input. If there are many solutions, print any of them.
Examples
Input
5 6
2 1 1
5 2 6
2 3 2
3 4 3
4 5 5
1 5 4
Output
2 2
1 3
Input
5 7
2 1 5
3 2 3
1 3 3
2 4 1
4 3 5
5 4 1
1 5 3
Output
3 3
3 4 7
Note
There are two simple cycles in the first example: 1 β 5 β 2 β 1 and 2 β 3 β 4 β 5 β 2. One traffic controller can only reverse the road 2 β 1 and he can't destroy the second cycle by himself. Two traffic controllers can reverse roads 2 β 1 and 2 β 3 which would satisfy the condition.
In the second example one traffic controller can't destroy the cycle 1 β 3 β 2 β 1 . With the help of three controllers we can, for example, reverse roads 1 β 3 , 2 β 4, 1 β 5.
Submitted Solution:
```
d={}
e={}
n,m=map(int,input().split())
for i in range(m):
u,v,c=map(int,input().split())
if u not in d:
d[u]=[v]
else:
d[u].append(v)
e[(u,v)]=(c,i+1)
paths=[]
def add_path(nodes,node):
ind=0
for i in nodes:
if i!=node:
ind+=1
else:
break
temp=nodes[ind:]
m=max(temp)
for i in range(len(nodes)):
if temp[i]==m:
ind=i
break
return(tuple(temp[ind:]+temp[:ind]+[m]))
visited=[False for i in range(n)]
def traverse(nodes,path,vertex):
if vertex in nodes:
paths.append(add_path(path,vertex))
else:
path=list(path)
nodes=set(nodes)
path.append(vertex)
nodes.add(vertex)
visited[vertex - 1]=True
for i in d[vertex]:
traverse(nodes,path,i)
return
while True:
if sum(visited) < n:
for i in range(n):
if visited[i] == False:
traverse(list(),set(),i+1)
break
else:
break
paths=list(set(paths))
max_value=max([e[i][0] for i in e])
ans=0
maxi=0
for i in paths:
mini=max_value
for j in range(len(i)-1):
if e[(i[j],i[j+1])][0] < mini:
mini=e[(i[j],i[j+1])][0]
if mini>maxi:
maxi=mini
print(maxi,end=" ")
ans=set()
for i in paths:
for j in range(len(i)-1):
if e[(i[j],i[j+1])][1] not in ans:
ans.add(e[(i[j],i[j+1])][1])
break
print(len(ans))
print(*sorted(list(ans)))
``` | instruction | 0 | 64,877 | 1 | 129,754 |
No | output | 1 | 64,877 | 1 | 129,755 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Farmer John has a farm that consists of n pastures connected by one-directional roads. Each road has a weight, representing the time it takes to go from the start to the end of the road. The roads could have negative weight, where the cows go so fast that they go back in time! However, Farmer John guarantees that it is impossible for the cows to get stuck in a time loop, where they can infinitely go back in time by traveling across a sequence of roads. Also, each pair of pastures is connected by at most one road in each direction.
Unfortunately, Farmer John lost the map of the farm. All he remembers is an array d, where d_i is the smallest amount of time it took the cows to reach the i-th pasture from pasture 1 using a sequence of roads. The cost of his farm is the sum of the weights of each of the roads, and Farmer John needs to know the minimal cost of a farm that is consistent with his memory.
Input
The first line contains one integer t (1 β€ t β€ 10^4) β the number of test cases. Then t cases follow.
The first line of each test case contains a single integer n (1 β€ n β€ 10^5) β the number of pastures.
The second line of each test case contains n space separated integers d_1, d_2, β¦, d_n (0 β€ d_i β€ 10^9) β the array d. It is guaranteed that d_1 = 0.
It is guaranteed that the sum of n over all test cases does not exceed 10^5.
Output
For each test case, output the minimum possible cost of a farm that is consistent with Farmer John's memory.
Example
Input
3
3
0 2 3
2
0 1000000000
1
0
Output
-3
0
0
Note
In the first test case, you can add roads
* from pasture 1 to pasture 2 with a time of 2,
* from pasture 2 to pasture 3 with a time of 1,
* from pasture 3 to pasture 1 with a time of -3,
* from pasture 3 to pasture 2 with a time of -1,
* from pasture 2 to pasture 1 with a time of -2.
The total cost is 2 + 1 + -3 + -1 + -2 = -3.
In the second test case, you can add a road from pasture 1 to pasture 2 with cost 1000000000 and a road from pasture 2 to pasture 1 with cost -1000000000. The total cost is 1000000000 + -1000000000 = 0.
In the third test case, you can't add any roads. The total cost is 0. | instruction | 0 | 65,108 | 1 | 130,216 |
Tags: constructive algorithms, graphs, greedy, shortest paths, sortings
Correct Solution:
```
# In the name of God.
# You are anything and We're nothing
# Ya ali!
import os
import sys
from io import BytesIO, IOBase
_str = str
str = lambda x=b"": x if type(x) is bytes else _str(x).encode()
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")
t = int(input())
while t > 0:
t -= 1
n = int(input())
a = list(map(int, input().split()))
a.sort()
ans = 0
for i in range(n - 1):
ans += (1 - (i + 1) * (n - i - 1)) * (a[i + 1] - a[i])
print(ans)
``` | output | 1 | 65,108 | 1 | 130,217 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Farmer John has a farm that consists of n pastures connected by one-directional roads. Each road has a weight, representing the time it takes to go from the start to the end of the road. The roads could have negative weight, where the cows go so fast that they go back in time! However, Farmer John guarantees that it is impossible for the cows to get stuck in a time loop, where they can infinitely go back in time by traveling across a sequence of roads. Also, each pair of pastures is connected by at most one road in each direction.
Unfortunately, Farmer John lost the map of the farm. All he remembers is an array d, where d_i is the smallest amount of time it took the cows to reach the i-th pasture from pasture 1 using a sequence of roads. The cost of his farm is the sum of the weights of each of the roads, and Farmer John needs to know the minimal cost of a farm that is consistent with his memory.
Input
The first line contains one integer t (1 β€ t β€ 10^4) β the number of test cases. Then t cases follow.
The first line of each test case contains a single integer n (1 β€ n β€ 10^5) β the number of pastures.
The second line of each test case contains n space separated integers d_1, d_2, β¦, d_n (0 β€ d_i β€ 10^9) β the array d. It is guaranteed that d_1 = 0.
It is guaranteed that the sum of n over all test cases does not exceed 10^5.
Output
For each test case, output the minimum possible cost of a farm that is consistent with Farmer John's memory.
Example
Input
3
3
0 2 3
2
0 1000000000
1
0
Output
-3
0
0
Note
In the first test case, you can add roads
* from pasture 1 to pasture 2 with a time of 2,
* from pasture 2 to pasture 3 with a time of 1,
* from pasture 3 to pasture 1 with a time of -3,
* from pasture 3 to pasture 2 with a time of -1,
* from pasture 2 to pasture 1 with a time of -2.
The total cost is 2 + 1 + -3 + -1 + -2 = -3.
In the second test case, you can add a road from pasture 1 to pasture 2 with cost 1000000000 and a road from pasture 2 to pasture 1 with cost -1000000000. The total cost is 1000000000 + -1000000000 = 0.
In the third test case, you can't add any roads. The total cost is 0. | instruction | 0 | 65,109 | 1 | 130,218 |
Tags: constructive algorithms, graphs, greedy, shortest paths, sortings
Correct Solution:
```
t = int(input())
for _ in range(t):
n = int(input())
a = list(map(int,input().split()))
a = sorted(a)
b = []
for i in range(1,n):
b += [a[i] - a[i-1]]
ans = 0
n = len(b)
for i in range(n):
ans -= (n-i)*(i+1)*(b[i])
print(ans + sum(b))
``` | output | 1 | 65,109 | 1 | 130,219 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Farmer John has a farm that consists of n pastures connected by one-directional roads. Each road has a weight, representing the time it takes to go from the start to the end of the road. The roads could have negative weight, where the cows go so fast that they go back in time! However, Farmer John guarantees that it is impossible for the cows to get stuck in a time loop, where they can infinitely go back in time by traveling across a sequence of roads. Also, each pair of pastures is connected by at most one road in each direction.
Unfortunately, Farmer John lost the map of the farm. All he remembers is an array d, where d_i is the smallest amount of time it took the cows to reach the i-th pasture from pasture 1 using a sequence of roads. The cost of his farm is the sum of the weights of each of the roads, and Farmer John needs to know the minimal cost of a farm that is consistent with his memory.
Input
The first line contains one integer t (1 β€ t β€ 10^4) β the number of test cases. Then t cases follow.
The first line of each test case contains a single integer n (1 β€ n β€ 10^5) β the number of pastures.
The second line of each test case contains n space separated integers d_1, d_2, β¦, d_n (0 β€ d_i β€ 10^9) β the array d. It is guaranteed that d_1 = 0.
It is guaranteed that the sum of n over all test cases does not exceed 10^5.
Output
For each test case, output the minimum possible cost of a farm that is consistent with Farmer John's memory.
Example
Input
3
3
0 2 3
2
0 1000000000
1
0
Output
-3
0
0
Note
In the first test case, you can add roads
* from pasture 1 to pasture 2 with a time of 2,
* from pasture 2 to pasture 3 with a time of 1,
* from pasture 3 to pasture 1 with a time of -3,
* from pasture 3 to pasture 2 with a time of -1,
* from pasture 2 to pasture 1 with a time of -2.
The total cost is 2 + 1 + -3 + -1 + -2 = -3.
In the second test case, you can add a road from pasture 1 to pasture 2 with cost 1000000000 and a road from pasture 2 to pasture 1 with cost -1000000000. The total cost is 1000000000 + -1000000000 = 0.
In the third test case, you can't add any roads. The total cost is 0. | instruction | 0 | 65,110 | 1 | 130,220 |
Tags: constructive algorithms, graphs, greedy, shortest paths, sortings
Correct Solution:
```
import sys
input = sys.stdin.readline
def stup(a):
r = 0
for i in range(len(a)):
for j in range(i+2,len(a)):
r -= a[j]-a[i]
return r
def solve():
n = int(input())
a = list(map(int, input().split()))
a.sort()
s = sum(a)
r = 0
for i in range(len(a)-2):
s -= a[i+1]
#r1 = 0
#for j in range(i+2,len(a)):
# r1 += a[j]#-a[i]
#print(r1, s)
r -= s - a[i]*(n-i-2)
print(r)#, stup(a))
for i in range(int(input())):
solve()
``` | output | 1 | 65,110 | 1 | 130,221 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Farmer John has a farm that consists of n pastures connected by one-directional roads. Each road has a weight, representing the time it takes to go from the start to the end of the road. The roads could have negative weight, where the cows go so fast that they go back in time! However, Farmer John guarantees that it is impossible for the cows to get stuck in a time loop, where they can infinitely go back in time by traveling across a sequence of roads. Also, each pair of pastures is connected by at most one road in each direction.
Unfortunately, Farmer John lost the map of the farm. All he remembers is an array d, where d_i is the smallest amount of time it took the cows to reach the i-th pasture from pasture 1 using a sequence of roads. The cost of his farm is the sum of the weights of each of the roads, and Farmer John needs to know the minimal cost of a farm that is consistent with his memory.
Input
The first line contains one integer t (1 β€ t β€ 10^4) β the number of test cases. Then t cases follow.
The first line of each test case contains a single integer n (1 β€ n β€ 10^5) β the number of pastures.
The second line of each test case contains n space separated integers d_1, d_2, β¦, d_n (0 β€ d_i β€ 10^9) β the array d. It is guaranteed that d_1 = 0.
It is guaranteed that the sum of n over all test cases does not exceed 10^5.
Output
For each test case, output the minimum possible cost of a farm that is consistent with Farmer John's memory.
Example
Input
3
3
0 2 3
2
0 1000000000
1
0
Output
-3
0
0
Note
In the first test case, you can add roads
* from pasture 1 to pasture 2 with a time of 2,
* from pasture 2 to pasture 3 with a time of 1,
* from pasture 3 to pasture 1 with a time of -3,
* from pasture 3 to pasture 2 with a time of -1,
* from pasture 2 to pasture 1 with a time of -2.
The total cost is 2 + 1 + -3 + -1 + -2 = -3.
In the second test case, you can add a road from pasture 1 to pasture 2 with cost 1000000000 and a road from pasture 2 to pasture 1 with cost -1000000000. The total cost is 1000000000 + -1000000000 = 0.
In the third test case, you can't add any roads. The total cost is 0. | instruction | 0 | 65,111 | 1 | 130,222 |
Tags: constructive algorithms, graphs, greedy, shortest paths, sortings
Correct Solution:
```
for _ in range(int(input())):
n=int(input());l=sorted(list(map(int,input().split())));f=0;count=0;
for i in range(2,n):count+=l[i-2];f-=(l[i]*(i-1));f+=count;
print(f);
``` | output | 1 | 65,111 | 1 | 130,223 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Farmer John has a farm that consists of n pastures connected by one-directional roads. Each road has a weight, representing the time it takes to go from the start to the end of the road. The roads could have negative weight, where the cows go so fast that they go back in time! However, Farmer John guarantees that it is impossible for the cows to get stuck in a time loop, where they can infinitely go back in time by traveling across a sequence of roads. Also, each pair of pastures is connected by at most one road in each direction.
Unfortunately, Farmer John lost the map of the farm. All he remembers is an array d, where d_i is the smallest amount of time it took the cows to reach the i-th pasture from pasture 1 using a sequence of roads. The cost of his farm is the sum of the weights of each of the roads, and Farmer John needs to know the minimal cost of a farm that is consistent with his memory.
Input
The first line contains one integer t (1 β€ t β€ 10^4) β the number of test cases. Then t cases follow.
The first line of each test case contains a single integer n (1 β€ n β€ 10^5) β the number of pastures.
The second line of each test case contains n space separated integers d_1, d_2, β¦, d_n (0 β€ d_i β€ 10^9) β the array d. It is guaranteed that d_1 = 0.
It is guaranteed that the sum of n over all test cases does not exceed 10^5.
Output
For each test case, output the minimum possible cost of a farm that is consistent with Farmer John's memory.
Example
Input
3
3
0 2 3
2
0 1000000000
1
0
Output
-3
0
0
Note
In the first test case, you can add roads
* from pasture 1 to pasture 2 with a time of 2,
* from pasture 2 to pasture 3 with a time of 1,
* from pasture 3 to pasture 1 with a time of -3,
* from pasture 3 to pasture 2 with a time of -1,
* from pasture 2 to pasture 1 with a time of -2.
The total cost is 2 + 1 + -3 + -1 + -2 = -3.
In the second test case, you can add a road from pasture 1 to pasture 2 with cost 1000000000 and a road from pasture 2 to pasture 1 with cost -1000000000. The total cost is 1000000000 + -1000000000 = 0.
In the third test case, you can't add any roads. The total cost is 0. | instruction | 0 | 65,112 | 1 | 130,224 |
Tags: constructive algorithms, graphs, greedy, shortest paths, sortings
Correct Solution:
```
import os, sys
from io import BytesIO, IOBase
from math import log2, ceil, sqrt, gcd
from _collections import deque
import heapq as hp
from bisect import bisect_left, bisect_right
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")
for i in range(int(input())):
n=int(input())
a=sorted(list(map(int,input().split())))
ans=0
tot=0
for i in range(1,n):
ans+=-i*a[i]+(a[i]-a[i-1])+tot
tot+=a[i]
print(ans)
``` | output | 1 | 65,112 | 1 | 130,225 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Farmer John has a farm that consists of n pastures connected by one-directional roads. Each road has a weight, representing the time it takes to go from the start to the end of the road. The roads could have negative weight, where the cows go so fast that they go back in time! However, Farmer John guarantees that it is impossible for the cows to get stuck in a time loop, where they can infinitely go back in time by traveling across a sequence of roads. Also, each pair of pastures is connected by at most one road in each direction.
Unfortunately, Farmer John lost the map of the farm. All he remembers is an array d, where d_i is the smallest amount of time it took the cows to reach the i-th pasture from pasture 1 using a sequence of roads. The cost of his farm is the sum of the weights of each of the roads, and Farmer John needs to know the minimal cost of a farm that is consistent with his memory.
Input
The first line contains one integer t (1 β€ t β€ 10^4) β the number of test cases. Then t cases follow.
The first line of each test case contains a single integer n (1 β€ n β€ 10^5) β the number of pastures.
The second line of each test case contains n space separated integers d_1, d_2, β¦, d_n (0 β€ d_i β€ 10^9) β the array d. It is guaranteed that d_1 = 0.
It is guaranteed that the sum of n over all test cases does not exceed 10^5.
Output
For each test case, output the minimum possible cost of a farm that is consistent with Farmer John's memory.
Example
Input
3
3
0 2 3
2
0 1000000000
1
0
Output
-3
0
0
Note
In the first test case, you can add roads
* from pasture 1 to pasture 2 with a time of 2,
* from pasture 2 to pasture 3 with a time of 1,
* from pasture 3 to pasture 1 with a time of -3,
* from pasture 3 to pasture 2 with a time of -1,
* from pasture 2 to pasture 1 with a time of -2.
The total cost is 2 + 1 + -3 + -1 + -2 = -3.
In the second test case, you can add a road from pasture 1 to pasture 2 with cost 1000000000 and a road from pasture 2 to pasture 1 with cost -1000000000. The total cost is 1000000000 + -1000000000 = 0.
In the third test case, you can't add any roads. The total cost is 0. | instruction | 0 | 65,113 | 1 | 130,226 |
Tags: constructive algorithms, graphs, greedy, shortest paths, sortings
Correct Solution:
```
''''
bahju vale ko chodkar sabka diff add kardo :okayge: shayd
'''
def f(a):
# print(sorted(a))
ans=0
n=len(a)
a=sorted(a)
for i in range(1,len(a)):
# print(ans,a[i],i-1,n-i-1-1)
ans+=(i-1)*(a[i])
ans-=max((n-i-1-1),0)*(a[i])
return -1*ans
# print(sum(a))
for _ in range(int(input())):
l=input()
lst=list(map(int,input().strip().split()))
print(f(lst))
``` | output | 1 | 65,113 | 1 | 130,227 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Farmer John has a farm that consists of n pastures connected by one-directional roads. Each road has a weight, representing the time it takes to go from the start to the end of the road. The roads could have negative weight, where the cows go so fast that they go back in time! However, Farmer John guarantees that it is impossible for the cows to get stuck in a time loop, where they can infinitely go back in time by traveling across a sequence of roads. Also, each pair of pastures is connected by at most one road in each direction.
Unfortunately, Farmer John lost the map of the farm. All he remembers is an array d, where d_i is the smallest amount of time it took the cows to reach the i-th pasture from pasture 1 using a sequence of roads. The cost of his farm is the sum of the weights of each of the roads, and Farmer John needs to know the minimal cost of a farm that is consistent with his memory.
Input
The first line contains one integer t (1 β€ t β€ 10^4) β the number of test cases. Then t cases follow.
The first line of each test case contains a single integer n (1 β€ n β€ 10^5) β the number of pastures.
The second line of each test case contains n space separated integers d_1, d_2, β¦, d_n (0 β€ d_i β€ 10^9) β the array d. It is guaranteed that d_1 = 0.
It is guaranteed that the sum of n over all test cases does not exceed 10^5.
Output
For each test case, output the minimum possible cost of a farm that is consistent with Farmer John's memory.
Example
Input
3
3
0 2 3
2
0 1000000000
1
0
Output
-3
0
0
Note
In the first test case, you can add roads
* from pasture 1 to pasture 2 with a time of 2,
* from pasture 2 to pasture 3 with a time of 1,
* from pasture 3 to pasture 1 with a time of -3,
* from pasture 3 to pasture 2 with a time of -1,
* from pasture 2 to pasture 1 with a time of -2.
The total cost is 2 + 1 + -3 + -1 + -2 = -3.
In the second test case, you can add a road from pasture 1 to pasture 2 with cost 1000000000 and a road from pasture 2 to pasture 1 with cost -1000000000. The total cost is 1000000000 + -1000000000 = 0.
In the third test case, you can't add any roads. The total cost is 0. | instruction | 0 | 65,114 | 1 | 130,228 |
Tags: constructive algorithms, graphs, greedy, shortest paths, sortings
Correct Solution:
```
t = int(input())
for o in range(t):
n = int(input())
d = list(map(int, input().strip().split()))
d.sort()
sm = []
cur = 0
for i in d:
cur += i
sm.append(cur)
subtract = sum(sm) - cur
add = 0
for i in range(n-1,-1,-1):
add += i*d[i]
print(subtract - add + d[-1])
``` | output | 1 | 65,114 | 1 | 130,229 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Farmer John has a farm that consists of n pastures connected by one-directional roads. Each road has a weight, representing the time it takes to go from the start to the end of the road. The roads could have negative weight, where the cows go so fast that they go back in time! However, Farmer John guarantees that it is impossible for the cows to get stuck in a time loop, where they can infinitely go back in time by traveling across a sequence of roads. Also, each pair of pastures is connected by at most one road in each direction.
Unfortunately, Farmer John lost the map of the farm. All he remembers is an array d, where d_i is the smallest amount of time it took the cows to reach the i-th pasture from pasture 1 using a sequence of roads. The cost of his farm is the sum of the weights of each of the roads, and Farmer John needs to know the minimal cost of a farm that is consistent with his memory.
Input
The first line contains one integer t (1 β€ t β€ 10^4) β the number of test cases. Then t cases follow.
The first line of each test case contains a single integer n (1 β€ n β€ 10^5) β the number of pastures.
The second line of each test case contains n space separated integers d_1, d_2, β¦, d_n (0 β€ d_i β€ 10^9) β the array d. It is guaranteed that d_1 = 0.
It is guaranteed that the sum of n over all test cases does not exceed 10^5.
Output
For each test case, output the minimum possible cost of a farm that is consistent with Farmer John's memory.
Example
Input
3
3
0 2 3
2
0 1000000000
1
0
Output
-3
0
0
Note
In the first test case, you can add roads
* from pasture 1 to pasture 2 with a time of 2,
* from pasture 2 to pasture 3 with a time of 1,
* from pasture 3 to pasture 1 with a time of -3,
* from pasture 3 to pasture 2 with a time of -1,
* from pasture 2 to pasture 1 with a time of -2.
The total cost is 2 + 1 + -3 + -1 + -2 = -3.
In the second test case, you can add a road from pasture 1 to pasture 2 with cost 1000000000 and a road from pasture 2 to pasture 1 with cost -1000000000. The total cost is 1000000000 + -1000000000 = 0.
In the third test case, you can't add any roads. The total cost is 0. | instruction | 0 | 65,115 | 1 | 130,230 |
Tags: constructive algorithms, graphs, greedy, shortest paths, sortings
Correct Solution:
```
# _
#####################################################################################################################
def main():
for i in range(int(input())):
nPastures, times = int(input()), sorted(map(int, input().split()))
if nPastures < 3:
print(0)
else:
print(minimumCost(nPastures-1, times))
def minimumCost(firstFactor, times):
costMin = times[-1] - firstFactor*(times[1] - times[0] + times[-1] - times[-2])
prevFactor = firstFactor
if firstFactor%2:
finalFactor = -(-firstFactor//2)
iPrev, jPrev = 1, firstFactor - 1
for i, j in zip(range(2, finalFactor + 1), range(firstFactor - 2, finalFactor - 1, -1)):
prevFactor += 2*jPrev - firstFactor
costMin -= prevFactor*(times[i] - times[iPrev] + times[jPrev] - times[j])
iPrev, jPrev = i, j
return costMin - (prevFactor + 2*finalFactor - firstFactor)*(times[finalFactor] - times[finalFactor-1])
finalFactor = firstFactor//2
iPrev, jPrev = 1, firstFactor - 1
for i, j in zip(range(2, finalFactor+1), range(firstFactor-2, finalFactor-1, -1)):
prevFactor += 2*jPrev - firstFactor
costMin -= prevFactor*(times[i] - times[iPrev] + times[jPrev] - times[j])
iPrev, jPrev = i, j
return costMin
if __name__ == '__main__':
# print(main())
main()
``` | output | 1 | 65,115 | 1 | 130,231 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Vasya went for a walk in the park. The park has n glades, numbered from 1 to n. There are m trails between the glades. The trails are numbered from 1 to m, where the i-th trail connects glades xi and yi. The numbers of the connected glades may be the same (xi = yi), which means that a trail connects a glade to itself. Also, two glades may have several non-intersecting trails between them.
Vasya is on glade 1, he wants to walk on all trails of the park exactly once, so that he can eventually return to glade 1. Unfortunately, Vasya does not know whether this walk is possible or not. Help Vasya, determine whether the walk is possible or not. If such walk is impossible, find the minimum number of trails the authorities need to add to the park in order to make the described walk possible.
Vasya can shift from one trail to another one only on glades. He can move on the trails in both directions. If Vasya started going on the trail that connects glades a and b, from glade a, then he must finish this trail on glade b.
Input
The first line contains two integers n and m (1 β€ n β€ 106; 0 β€ m β€ 106) β the number of glades in the park and the number of trails in the park, respectively. Next m lines specify the trails. The i-th line specifies the i-th trail as two space-separated numbers, xi, yi (1 β€ xi, yi β€ n) β the numbers of the glades connected by this trail.
Output
Print the single integer β the answer to the problem. If Vasya's walk is possible without adding extra trails, print 0, otherwise print the minimum number of trails the authorities need to add to the park in order to make Vasya's walk possible.
Examples
Input
3 3
1 2
2 3
3 1
Output
0
Input
2 5
1 1
1 2
1 2
2 2
1 2
Output
1
Note
In the first test case the described walk is possible without building extra trails. For example, let's first go on the first trail, then on the second one, and finally on the third one.
In the second test case the described walk is impossible without adding extra trails. To make the walk possible, it is enough to add one trail, for example, between glades number one and two.
Submitted Solution:
```
line = input().split()
n = int(line[0])
m = int(line[1])
a = [0 for i in range(n)]
for i in range(m):
line = input().split()
a[int(line[0])-1]+=1
a[int(line[1])-1] += 1
trails = 0
for i in range(n):
if a[i] % 2 == 1:
trails+=1
print(int(trails/2))
``` | instruction | 0 | 65,124 | 1 | 130,248 |
No | output | 1 | 65,124 | 1 | 130,249 |
Provide a correct Python 3 solution for this coding contest problem.
There are three airports A, B and C, and flights between each pair of airports in both directions.
A one-way flight between airports A and B takes P hours, a one-way flight between airports B and C takes Q hours, and a one-way flight between airports C and A takes R hours.
Consider a route where we start at one of the airports, fly to another airport and then fly to the other airport.
What is the minimum possible sum of the flight times?
Constraints
* 1 \leq P,Q,R \leq 100
* All values in input are integers.
Input
Input is given from Standard Input in the following format:
P Q R
Output
Print the minimum possible sum of the flight times.
Examples
Input
1 3 4
Output
4
Input
3 2 3
Output
5 | instruction | 0 | 65,443 | 1 | 130,886 |
"Correct Solution:
```
l=list(map(int,input().split()))
l.sort()
print(sum(l[0:2]))
``` | output | 1 | 65,443 | 1 | 130,887 |
Provide a correct Python 3 solution for this coding contest problem.
There are three airports A, B and C, and flights between each pair of airports in both directions.
A one-way flight between airports A and B takes P hours, a one-way flight between airports B and C takes Q hours, and a one-way flight between airports C and A takes R hours.
Consider a route where we start at one of the airports, fly to another airport and then fly to the other airport.
What is the minimum possible sum of the flight times?
Constraints
* 1 \leq P,Q,R \leq 100
* All values in input are integers.
Input
Input is given from Standard Input in the following format:
P Q R
Output
Print the minimum possible sum of the flight times.
Examples
Input
1 3 4
Output
4
Input
3 2 3
Output
5 | instruction | 0 | 65,444 | 1 | 130,888 |
"Correct Solution:
```
d = [int(i) for i in input().split()]
print(sum(d) - max(d))
``` | output | 1 | 65,444 | 1 | 130,889 |
Provide a correct Python 3 solution for this coding contest problem.
There are three airports A, B and C, and flights between each pair of airports in both directions.
A one-way flight between airports A and B takes P hours, a one-way flight between airports B and C takes Q hours, and a one-way flight between airports C and A takes R hours.
Consider a route where we start at one of the airports, fly to another airport and then fly to the other airport.
What is the minimum possible sum of the flight times?
Constraints
* 1 \leq P,Q,R \leq 100
* All values in input are integers.
Input
Input is given from Standard Input in the following format:
P Q R
Output
Print the minimum possible sum of the flight times.
Examples
Input
1 3 4
Output
4
Input
3 2 3
Output
5 | instruction | 0 | 65,445 | 1 | 130,890 |
"Correct Solution:
```
P,Q,R=map(int,input().split())
a=min(P+Q,P+R,Q+R)
print(a)
``` | output | 1 | 65,445 | 1 | 130,891 |
Provide a correct Python 3 solution for this coding contest problem.
There are three airports A, B and C, and flights between each pair of airports in both directions.
A one-way flight between airports A and B takes P hours, a one-way flight between airports B and C takes Q hours, and a one-way flight between airports C and A takes R hours.
Consider a route where we start at one of the airports, fly to another airport and then fly to the other airport.
What is the minimum possible sum of the flight times?
Constraints
* 1 \leq P,Q,R \leq 100
* All values in input are integers.
Input
Input is given from Standard Input in the following format:
P Q R
Output
Print the minimum possible sum of the flight times.
Examples
Input
1 3 4
Output
4
Input
3 2 3
Output
5 | instruction | 0 | 65,446 | 1 | 130,892 |
"Correct Solution:
```
V = list(map(int, input().split()))
print(sum(V) - max(V))
``` | output | 1 | 65,446 | 1 | 130,893 |
Provide a correct Python 3 solution for this coding contest problem.
There are three airports A, B and C, and flights between each pair of airports in both directions.
A one-way flight between airports A and B takes P hours, a one-way flight between airports B and C takes Q hours, and a one-way flight between airports C and A takes R hours.
Consider a route where we start at one of the airports, fly to another airport and then fly to the other airport.
What is the minimum possible sum of the flight times?
Constraints
* 1 \leq P,Q,R \leq 100
* All values in input are integers.
Input
Input is given from Standard Input in the following format:
P Q R
Output
Print the minimum possible sum of the flight times.
Examples
Input
1 3 4
Output
4
Input
3 2 3
Output
5 | instruction | 0 | 65,447 | 1 | 130,894 |
"Correct Solution:
```
P,Q,R = map(int,input().split())
print(min(P+Q,min(Q+R,R+P)))
``` | output | 1 | 65,447 | 1 | 130,895 |
Provide a correct Python 3 solution for this coding contest problem.
There are three airports A, B and C, and flights between each pair of airports in both directions.
A one-way flight between airports A and B takes P hours, a one-way flight between airports B and C takes Q hours, and a one-way flight between airports C and A takes R hours.
Consider a route where we start at one of the airports, fly to another airport and then fly to the other airport.
What is the minimum possible sum of the flight times?
Constraints
* 1 \leq P,Q,R \leq 100
* All values in input are integers.
Input
Input is given from Standard Input in the following format:
P Q R
Output
Print the minimum possible sum of the flight times.
Examples
Input
1 3 4
Output
4
Input
3 2 3
Output
5 | instruction | 0 | 65,448 | 1 | 130,896 |
"Correct Solution:
```
L = [int(i) for i in input().split()]
print(sum(L) - max(L))
``` | output | 1 | 65,448 | 1 | 130,897 |
Provide a correct Python 3 solution for this coding contest problem.
There are three airports A, B and C, and flights between each pair of airports in both directions.
A one-way flight between airports A and B takes P hours, a one-way flight between airports B and C takes Q hours, and a one-way flight between airports C and A takes R hours.
Consider a route where we start at one of the airports, fly to another airport and then fly to the other airport.
What is the minimum possible sum of the flight times?
Constraints
* 1 \leq P,Q,R \leq 100
* All values in input are integers.
Input
Input is given from Standard Input in the following format:
P Q R
Output
Print the minimum possible sum of the flight times.
Examples
Input
1 3 4
Output
4
Input
3 2 3
Output
5 | instruction | 0 | 65,449 | 1 | 130,898 |
"Correct Solution:
```
l=sorted(map(int,input().split()))
print(sum(l)-max(l))
``` | output | 1 | 65,449 | 1 | 130,899 |
Provide a correct Python 3 solution for this coding contest problem.
There are three airports A, B and C, and flights between each pair of airports in both directions.
A one-way flight between airports A and B takes P hours, a one-way flight between airports B and C takes Q hours, and a one-way flight between airports C and A takes R hours.
Consider a route where we start at one of the airports, fly to another airport and then fly to the other airport.
What is the minimum possible sum of the flight times?
Constraints
* 1 \leq P,Q,R \leq 100
* All values in input are integers.
Input
Input is given from Standard Input in the following format:
P Q R
Output
Print the minimum possible sum of the flight times.
Examples
Input
1 3 4
Output
4
Input
3 2 3
Output
5 | instruction | 0 | 65,450 | 1 | 130,900 |
"Correct Solution:
```
l = sorted(map(int, input().split()))
print(l[0]+l[1])
``` | output | 1 | 65,450 | 1 | 130,901 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
There are three airports A, B and C, and flights between each pair of airports in both directions.
A one-way flight between airports A and B takes P hours, a one-way flight between airports B and C takes Q hours, and a one-way flight between airports C and A takes R hours.
Consider a route where we start at one of the airports, fly to another airport and then fly to the other airport.
What is the minimum possible sum of the flight times?
Constraints
* 1 \leq P,Q,R \leq 100
* All values in input are integers.
Input
Input is given from Standard Input in the following format:
P Q R
Output
Print the minimum possible sum of the flight times.
Examples
Input
1 3 4
Output
4
Input
3 2 3
Output
5
Submitted Solution:
```
p,q,r=map(int,input().split())
print(min(p+q,q+r,p+r))
``` | instruction | 0 | 65,451 | 1 | 130,902 |
Yes | output | 1 | 65,451 | 1 | 130,903 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
There are three airports A, B and C, and flights between each pair of airports in both directions.
A one-way flight between airports A and B takes P hours, a one-way flight between airports B and C takes Q hours, and a one-way flight between airports C and A takes R hours.
Consider a route where we start at one of the airports, fly to another airport and then fly to the other airport.
What is the minimum possible sum of the flight times?
Constraints
* 1 \leq P,Q,R \leq 100
* All values in input are integers.
Input
Input is given from Standard Input in the following format:
P Q R
Output
Print the minimum possible sum of the flight times.
Examples
Input
1 3 4
Output
4
Input
3 2 3
Output
5
Submitted Solution:
```
t = list(map(int, input().split()))
print(sum(t) - max(t))
``` | instruction | 0 | 65,452 | 1 | 130,904 |
Yes | output | 1 | 65,452 | 1 | 130,905 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
There are three airports A, B and C, and flights between each pair of airports in both directions.
A one-way flight between airports A and B takes P hours, a one-way flight between airports B and C takes Q hours, and a one-way flight between airports C and A takes R hours.
Consider a route where we start at one of the airports, fly to another airport and then fly to the other airport.
What is the minimum possible sum of the flight times?
Constraints
* 1 \leq P,Q,R \leq 100
* All values in input are integers.
Input
Input is given from Standard Input in the following format:
P Q R
Output
Print the minimum possible sum of the flight times.
Examples
Input
1 3 4
Output
4
Input
3 2 3
Output
5
Submitted Solution:
```
s = list(map(int, input().split()))
print(sum(s) - max(s))
``` | instruction | 0 | 65,453 | 1 | 130,906 |
Yes | output | 1 | 65,453 | 1 | 130,907 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
There are three airports A, B and C, and flights between each pair of airports in both directions.
A one-way flight between airports A and B takes P hours, a one-way flight between airports B and C takes Q hours, and a one-way flight between airports C and A takes R hours.
Consider a route where we start at one of the airports, fly to another airport and then fly to the other airport.
What is the minimum possible sum of the flight times?
Constraints
* 1 \leq P,Q,R \leq 100
* All values in input are integers.
Input
Input is given from Standard Input in the following format:
P Q R
Output
Print the minimum possible sum of the flight times.
Examples
Input
1 3 4
Output
4
Input
3 2 3
Output
5
Submitted Solution:
```
print(sum(sorted(list(map(int, input().split())))[:-1]))
``` | instruction | 0 | 65,454 | 1 | 130,908 |
Yes | output | 1 | 65,454 | 1 | 130,909 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
There are three airports A, B and C, and flights between each pair of airports in both directions.
A one-way flight between airports A and B takes P hours, a one-way flight between airports B and C takes Q hours, and a one-way flight between airports C and A takes R hours.
Consider a route where we start at one of the airports, fly to another airport and then fly to the other airport.
What is the minimum possible sum of the flight times?
Constraints
* 1 \leq P,Q,R \leq 100
* All values in input are integers.
Input
Input is given from Standard Input in the following format:
P Q R
Output
Print the minimum possible sum of the flight times.
Examples
Input
1 3 4
Output
4
Input
3 2 3
Output
5
Submitted Solution:
```
p = input('P:')
q = input('Q:')
r = input('R:')
ABC = p + q
BCA = q + r
CAB = r + p
min = ABC
if min > BCA:
min = BCA
if min > CAB:
min = CAB
print(min)
``` | instruction | 0 | 65,455 | 1 | 130,910 |
No | output | 1 | 65,455 | 1 | 130,911 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
There are three airports A, B and C, and flights between each pair of airports in both directions.
A one-way flight between airports A and B takes P hours, a one-way flight between airports B and C takes Q hours, and a one-way flight between airports C and A takes R hours.
Consider a route where we start at one of the airports, fly to another airport and then fly to the other airport.
What is the minimum possible sum of the flight times?
Constraints
* 1 \leq P,Q,R \leq 100
* All values in input are integers.
Input
Input is given from Standard Input in the following format:
P Q R
Output
Print the minimum possible sum of the flight times.
Examples
Input
1 3 4
Output
4
Input
3 2 3
Output
5
Submitted Solution:
```
import bisect,collections,copy,heapq,itertools,math,string
import sys
def S(): return sys.stdin.readline().rstrip()
def M(): return map(int,sys.stdin.readline().rstrip().split())
def I(): return int(sys.stdin.readline().rstrip())
def LI(): return list(map(int,sys.stdin.readline().rstrip().split()))
def LS(): return list(sys.stdin.readline().rstrip().split())
l = LI()
print(l[0]+l[1])
``` | instruction | 0 | 65,456 | 1 | 130,912 |
No | output | 1 | 65,456 | 1 | 130,913 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
There are three airports A, B and C, and flights between each pair of airports in both directions.
A one-way flight between airports A and B takes P hours, a one-way flight between airports B and C takes Q hours, and a one-way flight between airports C and A takes R hours.
Consider a route where we start at one of the airports, fly to another airport and then fly to the other airport.
What is the minimum possible sum of the flight times?
Constraints
* 1 \leq P,Q,R \leq 100
* All values in input are integers.
Input
Input is given from Standard Input in the following format:
P Q R
Output
Print the minimum possible sum of the flight times.
Examples
Input
1 3 4
Output
4
Input
3 2 3
Output
5
Submitted Solution:
```
n=list(map(int, input().strip().split()))
lis1=[]
for i in range(0,len(n)):
for a in range(0,len(n)):
if n[i]!=n[a]:
z=(int(n[a])+int(n[i]))
lis1.append(z)
minscore='9999999999'
for i in range(0,len(lis1)):
if float(minscore)>float(lis1[i]):
minscore=lis1[i]
print(minscore)
``` | instruction | 0 | 65,457 | 1 | 130,914 |
No | output | 1 | 65,457 | 1 | 130,915 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
There are three airports A, B and C, and flights between each pair of airports in both directions.
A one-way flight between airports A and B takes P hours, a one-way flight between airports B and C takes Q hours, and a one-way flight between airports C and A takes R hours.
Consider a route where we start at one of the airports, fly to another airport and then fly to the other airport.
What is the minimum possible sum of the flight times?
Constraints
* 1 \leq P,Q,R \leq 100
* All values in input are integers.
Input
Input is given from Standard Input in the following format:
P Q R
Output
Print the minimum possible sum of the flight times.
Examples
Input
1 3 4
Output
4
Input
3 2 3
Output
5
Submitted Solution:
```
count = int(input())
nums = list(map(int, input().split()))
minAbs = 0
isFirst = True
for i in range(count):
leftSum = 0
rightSum = 0
for leftIndex in range(i + 1):
leftSum += nums[leftIndex]
for rightIndex in range(i + 1, count):
rightSum += nums[rightIndex]
if isFirst:
minAbs = abs(leftSum - rightSum)
else:
minAbs = min(abs(leftSum - rightSum),minAbs)
isFirst = False
print(minAbs)
``` | instruction | 0 | 65,458 | 1 | 130,916 |
No | output | 1 | 65,458 | 1 | 130,917 |
Provide a correct Python 3 solution for this coding contest problem.
There are N islands lining up from west to east, connected by N-1 bridges.
The i-th bridge connects the i-th island from the west and the (i+1)-th island from the west.
One day, disputes took place between some islands, and there were M requests from the inhabitants of the islands:
Request i: A dispute took place between the a_i-th island from the west and the b_i-th island from the west. Please make traveling between these islands with bridges impossible.
You decided to remove some bridges to meet all these M requests.
Find the minimum number of bridges that must be removed.
Constraints
* All values in input are integers.
* 2 \leq N \leq 10^5
* 1 \leq M \leq 10^5
* 1 \leq a_i < b_i \leq N
* All pairs (a_i, b_i) are distinct.
Input
Input is given from Standard Input in the following format:
N M
a_1 b_1
a_2 b_2
:
a_M b_M
Output
Print the minimum number of bridges that must be removed.
Examples
Input
5 2
1 4
2 5
Output
1
Input
9 5
1 8
2 7
3 5
4 6
7 9
Output
2
Input
5 10
1 2
1 3
1 4
1 5
2 3
2 4
2 5
3 4
3 5
4 5
Output
4 | instruction | 0 | 65,475 | 1 | 130,950 |
"Correct Solution:
```
n,m = map(int,input().split())
a = [list(map(int,input().split())) for _ in range(m)]
a = sorted(a,key=lambda x:x[1])
ans = [0]
for a_ in a:
if not a_[0] < ans[-1] <= a_[1]:
ans.append(a_[1])
print(len(ans)-1)
``` | output | 1 | 65,475 | 1 | 130,951 |
Provide a correct Python 3 solution for this coding contest problem.
There are N islands lining up from west to east, connected by N-1 bridges.
The i-th bridge connects the i-th island from the west and the (i+1)-th island from the west.
One day, disputes took place between some islands, and there were M requests from the inhabitants of the islands:
Request i: A dispute took place between the a_i-th island from the west and the b_i-th island from the west. Please make traveling between these islands with bridges impossible.
You decided to remove some bridges to meet all these M requests.
Find the minimum number of bridges that must be removed.
Constraints
* All values in input are integers.
* 2 \leq N \leq 10^5
* 1 \leq M \leq 10^5
* 1 \leq a_i < b_i \leq N
* All pairs (a_i, b_i) are distinct.
Input
Input is given from Standard Input in the following format:
N M
a_1 b_1
a_2 b_2
:
a_M b_M
Output
Print the minimum number of bridges that must be removed.
Examples
Input
5 2
1 4
2 5
Output
1
Input
9 5
1 8
2 7
3 5
4 6
7 9
Output
2
Input
5 10
1 2
1 3
1 4
1 5
2 3
2 4
2 5
3 4
3 5
4 5
Output
4 | instruction | 0 | 65,476 | 1 | 130,952 |
"Correct Solution:
```
N, M = map(int, input().split())
AB = [tuple(map(int, input().split())) for _ in range(M)]
AB.sort(key=lambda ab:(ab[1],ab[0]))
ans = 0
pre = 0
for a, b in AB:
if pre <= a:
pre = b
ans += 1
print(ans)
``` | output | 1 | 65,476 | 1 | 130,953 |
Provide a correct Python 3 solution for this coding contest problem.
There are N islands lining up from west to east, connected by N-1 bridges.
The i-th bridge connects the i-th island from the west and the (i+1)-th island from the west.
One day, disputes took place between some islands, and there were M requests from the inhabitants of the islands:
Request i: A dispute took place between the a_i-th island from the west and the b_i-th island from the west. Please make traveling between these islands with bridges impossible.
You decided to remove some bridges to meet all these M requests.
Find the minimum number of bridges that must be removed.
Constraints
* All values in input are integers.
* 2 \leq N \leq 10^5
* 1 \leq M \leq 10^5
* 1 \leq a_i < b_i \leq N
* All pairs (a_i, b_i) are distinct.
Input
Input is given from Standard Input in the following format:
N M
a_1 b_1
a_2 b_2
:
a_M b_M
Output
Print the minimum number of bridges that must be removed.
Examples
Input
5 2
1 4
2 5
Output
1
Input
9 5
1 8
2 7
3 5
4 6
7 9
Output
2
Input
5 10
1 2
1 3
1 4
1 5
2 3
2 4
2 5
3 4
3 5
4 5
Output
4 | instruction | 0 | 65,477 | 1 | 130,954 |
"Correct Solution:
```
n, m = map(int, input().split())
ab = sorted([tuple(map(int, input().split())) for _ in range(m)], key=lambda x: x[1])
broken = -1
ans = 0
for a, b in ab:
if broken < a:
broken = b - 1
ans += 1
print(ans)
``` | output | 1 | 65,477 | 1 | 130,955 |
Provide a correct Python 3 solution for this coding contest problem.
There are N islands lining up from west to east, connected by N-1 bridges.
The i-th bridge connects the i-th island from the west and the (i+1)-th island from the west.
One day, disputes took place between some islands, and there were M requests from the inhabitants of the islands:
Request i: A dispute took place between the a_i-th island from the west and the b_i-th island from the west. Please make traveling between these islands with bridges impossible.
You decided to remove some bridges to meet all these M requests.
Find the minimum number of bridges that must be removed.
Constraints
* All values in input are integers.
* 2 \leq N \leq 10^5
* 1 \leq M \leq 10^5
* 1 \leq a_i < b_i \leq N
* All pairs (a_i, b_i) are distinct.
Input
Input is given from Standard Input in the following format:
N M
a_1 b_1
a_2 b_2
:
a_M b_M
Output
Print the minimum number of bridges that must be removed.
Examples
Input
5 2
1 4
2 5
Output
1
Input
9 5
1 8
2 7
3 5
4 6
7 9
Output
2
Input
5 10
1 2
1 3
1 4
1 5
2 3
2 4
2 5
3 4
3 5
4 5
Output
4 | instruction | 0 | 65,478 | 1 | 130,956 |
"Correct Solution:
```
n,m=map(int,input().split())
lst=[list(map(int,input().split())) for i in range(m)]
lst.sort(key=lambda x:x[1])
ans=1
pin=lst[0][1]-1
for i in range(1,m):
if lst[i][0]>pin:
ans+=1
pin=lst[i][1]-1
print(ans)
``` | output | 1 | 65,478 | 1 | 130,957 |
Provide a correct Python 3 solution for this coding contest problem.
There are N islands lining up from west to east, connected by N-1 bridges.
The i-th bridge connects the i-th island from the west and the (i+1)-th island from the west.
One day, disputes took place between some islands, and there were M requests from the inhabitants of the islands:
Request i: A dispute took place between the a_i-th island from the west and the b_i-th island from the west. Please make traveling between these islands with bridges impossible.
You decided to remove some bridges to meet all these M requests.
Find the minimum number of bridges that must be removed.
Constraints
* All values in input are integers.
* 2 \leq N \leq 10^5
* 1 \leq M \leq 10^5
* 1 \leq a_i < b_i \leq N
* All pairs (a_i, b_i) are distinct.
Input
Input is given from Standard Input in the following format:
N M
a_1 b_1
a_2 b_2
:
a_M b_M
Output
Print the minimum number of bridges that must be removed.
Examples
Input
5 2
1 4
2 5
Output
1
Input
9 5
1 8
2 7
3 5
4 6
7 9
Output
2
Input
5 10
1 2
1 3
1 4
1 5
2 3
2 4
2 5
3 4
3 5
4 5
Output
4 | instruction | 0 | 65,479 | 1 | 130,958 |
"Correct Solution:
```
#!/usr/bin/env python3
(n,m,),*b=[[*map(int,i.split())]for i in open(0)]
b=sorted(b,key=lambda x:x[1])
p=0
c=0
for i in b:
if i[0]>=p:
c+=1
p=i[1]
print(c)
``` | output | 1 | 65,479 | 1 | 130,959 |
Provide a correct Python 3 solution for this coding contest problem.
There are N islands lining up from west to east, connected by N-1 bridges.
The i-th bridge connects the i-th island from the west and the (i+1)-th island from the west.
One day, disputes took place between some islands, and there were M requests from the inhabitants of the islands:
Request i: A dispute took place between the a_i-th island from the west and the b_i-th island from the west. Please make traveling between these islands with bridges impossible.
You decided to remove some bridges to meet all these M requests.
Find the minimum number of bridges that must be removed.
Constraints
* All values in input are integers.
* 2 \leq N \leq 10^5
* 1 \leq M \leq 10^5
* 1 \leq a_i < b_i \leq N
* All pairs (a_i, b_i) are distinct.
Input
Input is given from Standard Input in the following format:
N M
a_1 b_1
a_2 b_2
:
a_M b_M
Output
Print the minimum number of bridges that must be removed.
Examples
Input
5 2
1 4
2 5
Output
1
Input
9 5
1 8
2 7
3 5
4 6
7 9
Output
2
Input
5 10
1 2
1 3
1 4
1 5
2 3
2 4
2 5
3 4
3 5
4 5
Output
4 | instruction | 0 | 65,480 | 1 | 130,960 |
"Correct Solution:
```
N,M = map(int,input().split())
AB = [tuple(map(int,input().split())) for i in range(M)]
AB.sort(key=lambda x:x[1])
last = -1
ans = 0
for a,b in AB:
if a <= last < b: continue
last = b-1
ans += 1
print(ans)
``` | output | 1 | 65,480 | 1 | 130,961 |
Provide a correct Python 3 solution for this coding contest problem.
There are N islands lining up from west to east, connected by N-1 bridges.
The i-th bridge connects the i-th island from the west and the (i+1)-th island from the west.
One day, disputes took place between some islands, and there were M requests from the inhabitants of the islands:
Request i: A dispute took place between the a_i-th island from the west and the b_i-th island from the west. Please make traveling between these islands with bridges impossible.
You decided to remove some bridges to meet all these M requests.
Find the minimum number of bridges that must be removed.
Constraints
* All values in input are integers.
* 2 \leq N \leq 10^5
* 1 \leq M \leq 10^5
* 1 \leq a_i < b_i \leq N
* All pairs (a_i, b_i) are distinct.
Input
Input is given from Standard Input in the following format:
N M
a_1 b_1
a_2 b_2
:
a_M b_M
Output
Print the minimum number of bridges that must be removed.
Examples
Input
5 2
1 4
2 5
Output
1
Input
9 5
1 8
2 7
3 5
4 6
7 9
Output
2
Input
5 10
1 2
1 3
1 4
1 5
2 3
2 4
2 5
3 4
3 5
4 5
Output
4 | instruction | 0 | 65,481 | 1 | 130,962 |
"Correct Solution:
```
n,m=map(int,input().split())
mx =[-1 for i in range(0,n)]
for z in range(0,m):
a,b=map(int,input().split())
mx[b-1]=max(mx[b-1],a-1)
cut=-1
cn=0
for z in range(0,n):
if cut<mx[z]:
cut=z-1
cn=cn+1
print(cn)
``` | output | 1 | 65,481 | 1 | 130,963 |
Provide a correct Python 3 solution for this coding contest problem.
There are N islands lining up from west to east, connected by N-1 bridges.
The i-th bridge connects the i-th island from the west and the (i+1)-th island from the west.
One day, disputes took place between some islands, and there were M requests from the inhabitants of the islands:
Request i: A dispute took place between the a_i-th island from the west and the b_i-th island from the west. Please make traveling between these islands with bridges impossible.
You decided to remove some bridges to meet all these M requests.
Find the minimum number of bridges that must be removed.
Constraints
* All values in input are integers.
* 2 \leq N \leq 10^5
* 1 \leq M \leq 10^5
* 1 \leq a_i < b_i \leq N
* All pairs (a_i, b_i) are distinct.
Input
Input is given from Standard Input in the following format:
N M
a_1 b_1
a_2 b_2
:
a_M b_M
Output
Print the minimum number of bridges that must be removed.
Examples
Input
5 2
1 4
2 5
Output
1
Input
9 5
1 8
2 7
3 5
4 6
7 9
Output
2
Input
5 10
1 2
1 3
1 4
1 5
2 3
2 4
2 5
3 4
3 5
4 5
Output
4 | instruction | 0 | 65,482 | 1 | 130,964 |
"Correct Solution:
```
N, M = map(int, input().split())
bs = [tuple(map(int, input().split())) for _ in range(M)]
bs.sort(key=lambda x: x[1])
rbs = []
for a, b in bs:
if not rbs or a > rbs[-1]:
rbs.append(b - 1)
ans = len(rbs)
print(ans)
``` | output | 1 | 65,482 | 1 | 130,965 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
There are N islands lining up from west to east, connected by N-1 bridges.
The i-th bridge connects the i-th island from the west and the (i+1)-th island from the west.
One day, disputes took place between some islands, and there were M requests from the inhabitants of the islands:
Request i: A dispute took place between the a_i-th island from the west and the b_i-th island from the west. Please make traveling between these islands with bridges impossible.
You decided to remove some bridges to meet all these M requests.
Find the minimum number of bridges that must be removed.
Constraints
* All values in input are integers.
* 2 \leq N \leq 10^5
* 1 \leq M \leq 10^5
* 1 \leq a_i < b_i \leq N
* All pairs (a_i, b_i) are distinct.
Input
Input is given from Standard Input in the following format:
N M
a_1 b_1
a_2 b_2
:
a_M b_M
Output
Print the minimum number of bridges that must be removed.
Examples
Input
5 2
1 4
2 5
Output
1
Input
9 5
1 8
2 7
3 5
4 6
7 9
Output
2
Input
5 10
1 2
1 3
1 4
1 5
2 3
2 4
2 5
3 4
3 5
4 5
Output
4
Submitted Solution:
```
N,M=map(int,input().split())
ab=[list(map(int,input().split())) for i in range(M)]
ab.sort(key=lambda x:x[1])
now=0
ans=0
for i in range(M):
if now<=ab[i][0]:
now=ab[i][1]
ans+=1
print(ans)
``` | instruction | 0 | 65,483 | 1 | 130,966 |
Yes | output | 1 | 65,483 | 1 | 130,967 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
There are N islands lining up from west to east, connected by N-1 bridges.
The i-th bridge connects the i-th island from the west and the (i+1)-th island from the west.
One day, disputes took place between some islands, and there were M requests from the inhabitants of the islands:
Request i: A dispute took place between the a_i-th island from the west and the b_i-th island from the west. Please make traveling between these islands with bridges impossible.
You decided to remove some bridges to meet all these M requests.
Find the minimum number of bridges that must be removed.
Constraints
* All values in input are integers.
* 2 \leq N \leq 10^5
* 1 \leq M \leq 10^5
* 1 \leq a_i < b_i \leq N
* All pairs (a_i, b_i) are distinct.
Input
Input is given from Standard Input in the following format:
N M
a_1 b_1
a_2 b_2
:
a_M b_M
Output
Print the minimum number of bridges that must be removed.
Examples
Input
5 2
1 4
2 5
Output
1
Input
9 5
1 8
2 7
3 5
4 6
7 9
Output
2
Input
5 10
1 2
1 3
1 4
1 5
2 3
2 4
2 5
3 4
3 5
4 5
Output
4
Submitted Solution:
```
n,m,*t=map(int,open(0).read().split());r=[n+1]*(n+1)
for a,b in zip(*[iter(t)]*2):
r[a]=min(r[a],b)
a=0;cur=n+1
for i in range(n+1):
cur=min(cur, r[i])
if i==cur:
cur=r[i]
a+=1
print(a)
``` | instruction | 0 | 65,484 | 1 | 130,968 |
Yes | output | 1 | 65,484 | 1 | 130,969 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
There are N islands lining up from west to east, connected by N-1 bridges.
The i-th bridge connects the i-th island from the west and the (i+1)-th island from the west.
One day, disputes took place between some islands, and there were M requests from the inhabitants of the islands:
Request i: A dispute took place between the a_i-th island from the west and the b_i-th island from the west. Please make traveling between these islands with bridges impossible.
You decided to remove some bridges to meet all these M requests.
Find the minimum number of bridges that must be removed.
Constraints
* All values in input are integers.
* 2 \leq N \leq 10^5
* 1 \leq M \leq 10^5
* 1 \leq a_i < b_i \leq N
* All pairs (a_i, b_i) are distinct.
Input
Input is given from Standard Input in the following format:
N M
a_1 b_1
a_2 b_2
:
a_M b_M
Output
Print the minimum number of bridges that must be removed.
Examples
Input
5 2
1 4
2 5
Output
1
Input
9 5
1 8
2 7
3 5
4 6
7 9
Output
2
Input
5 10
1 2
1 3
1 4
1 5
2 3
2 4
2 5
3 4
3 5
4 5
Output
4
Submitted Solution:
```
n, m = map(int, input().split())
war = [tuple(map(int, input().split())) for _ in range(m)]
war.sort(key=lambda x: x[1])
ans = 0
tmp = -1
for l, r in war:
if tmp <= l:
ans += 1
tmp = r
print(ans)
``` | instruction | 0 | 65,485 | 1 | 130,970 |
Yes | output | 1 | 65,485 | 1 | 130,971 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
There are N islands lining up from west to east, connected by N-1 bridges.
The i-th bridge connects the i-th island from the west and the (i+1)-th island from the west.
One day, disputes took place between some islands, and there were M requests from the inhabitants of the islands:
Request i: A dispute took place between the a_i-th island from the west and the b_i-th island from the west. Please make traveling between these islands with bridges impossible.
You decided to remove some bridges to meet all these M requests.
Find the minimum number of bridges that must be removed.
Constraints
* All values in input are integers.
* 2 \leq N \leq 10^5
* 1 \leq M \leq 10^5
* 1 \leq a_i < b_i \leq N
* All pairs (a_i, b_i) are distinct.
Input
Input is given from Standard Input in the following format:
N M
a_1 b_1
a_2 b_2
:
a_M b_M
Output
Print the minimum number of bridges that must be removed.
Examples
Input
5 2
1 4
2 5
Output
1
Input
9 5
1 8
2 7
3 5
4 6
7 9
Output
2
Input
5 10
1 2
1 3
1 4
1 5
2 3
2 4
2 5
3 4
3 5
4 5
Output
4
Submitted Solution:
```
n,m = map(int,input().split())
x=y=0
lst=sorted([list(map(int,input().split())) for i in range(m)],key=lambda x:x[1])
for a,b in lst:
if a>x:
y+=1
x=b-1
print(y)
``` | instruction | 0 | 65,486 | 1 | 130,972 |
Yes | output | 1 | 65,486 | 1 | 130,973 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
There are N islands lining up from west to east, connected by N-1 bridges.
The i-th bridge connects the i-th island from the west and the (i+1)-th island from the west.
One day, disputes took place between some islands, and there were M requests from the inhabitants of the islands:
Request i: A dispute took place between the a_i-th island from the west and the b_i-th island from the west. Please make traveling between these islands with bridges impossible.
You decided to remove some bridges to meet all these M requests.
Find the minimum number of bridges that must be removed.
Constraints
* All values in input are integers.
* 2 \leq N \leq 10^5
* 1 \leq M \leq 10^5
* 1 \leq a_i < b_i \leq N
* All pairs (a_i, b_i) are distinct.
Input
Input is given from Standard Input in the following format:
N M
a_1 b_1
a_2 b_2
:
a_M b_M
Output
Print the minimum number of bridges that must be removed.
Examples
Input
5 2
1 4
2 5
Output
1
Input
9 5
1 8
2 7
3 5
4 6
7 9
Output
2
Input
5 10
1 2
1 3
1 4
1 5
2 3
2 4
2 5
3 4
3 5
4 5
Output
4
Submitted Solution:
```
N, M = map(int,input().split())
m=[list(map(int, input().split())) for _ in range(M)]
m=sorted(m, key=lambda x: x[1])
p=0
while m!=[]:
tmp=m[-1][1]-1
while m!=[] and m[-1][1]>tmp:
m.pop()
p+=1
print(p)
``` | instruction | 0 | 65,487 | 1 | 130,974 |
No | output | 1 | 65,487 | 1 | 130,975 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
There are N islands lining up from west to east, connected by N-1 bridges.
The i-th bridge connects the i-th island from the west and the (i+1)-th island from the west.
One day, disputes took place between some islands, and there were M requests from the inhabitants of the islands:
Request i: A dispute took place between the a_i-th island from the west and the b_i-th island from the west. Please make traveling between these islands with bridges impossible.
You decided to remove some bridges to meet all these M requests.
Find the minimum number of bridges that must be removed.
Constraints
* All values in input are integers.
* 2 \leq N \leq 10^5
* 1 \leq M \leq 10^5
* 1 \leq a_i < b_i \leq N
* All pairs (a_i, b_i) are distinct.
Input
Input is given from Standard Input in the following format:
N M
a_1 b_1
a_2 b_2
:
a_M b_M
Output
Print the minimum number of bridges that must be removed.
Examples
Input
5 2
1 4
2 5
Output
1
Input
9 5
1 8
2 7
3 5
4 6
7 9
Output
2
Input
5 10
1 2
1 3
1 4
1 5
2 3
2 4
2 5
3 4
3 5
4 5
Output
4
Submitted Solution:
```
N, M = map(int, input().split())
ab = [0] * M
for _ in range(M):
a, b = map(int, input().split())
ab[a].append(b)
dp = [0] * (N + 1)
for i in range(1, N + 1):
dp[i] = max(dp[i], dp[i - 1])
for j in ab[i]:
dp[j] = max(dp[j], dp[i] + 1)
print(dp[N])
``` | instruction | 0 | 65,488 | 1 | 130,976 |
No | output | 1 | 65,488 | 1 | 130,977 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
There are N islands lining up from west to east, connected by N-1 bridges.
The i-th bridge connects the i-th island from the west and the (i+1)-th island from the west.
One day, disputes took place between some islands, and there were M requests from the inhabitants of the islands:
Request i: A dispute took place between the a_i-th island from the west and the b_i-th island from the west. Please make traveling between these islands with bridges impossible.
You decided to remove some bridges to meet all these M requests.
Find the minimum number of bridges that must be removed.
Constraints
* All values in input are integers.
* 2 \leq N \leq 10^5
* 1 \leq M \leq 10^5
* 1 \leq a_i < b_i \leq N
* All pairs (a_i, b_i) are distinct.
Input
Input is given from Standard Input in the following format:
N M
a_1 b_1
a_2 b_2
:
a_M b_M
Output
Print the minimum number of bridges that must be removed.
Examples
Input
5 2
1 4
2 5
Output
1
Input
9 5
1 8
2 7
3 5
4 6
7 9
Output
2
Input
5 10
1 2
1 3
1 4
1 5
2 3
2 4
2 5
3 4
3 5
4 5
Output
4
Submitted Solution:
```
N, M = map(int, input().split())
_a, _b = map(int, input().split())
dict_paths = {}
dict_paths[_a] = _b
for i in range(M - 1) :
a, b = map(int, input().split())
interleave_flg = False
for k in dict_paths.keys() :
k_tmp, k_val_tmp = k, dict_paths[k]
# complete intersect
if a >= k and b <= dict_paths[k] :
dict_paths.pop(k)
dict_paths[a] = b
interleave_flg = True
# nothing required
elif a <= k and b >= dict_paths[k] :
interleave_flg = True
# left partial
elif a < k and b > k and b <= dict_paths[k] :
dict_paths.pop(k)
dict_paths[a] = k_val_tmp
interleave_flg = True
# right partial
elif a > k and a < dict_paths[k] and b >= dict_paths[k] :
dict_paths.pop(k)
dict_paths[k] = b
interleave_flg = True
if interleave_flg == False :
dict_paths[a] = b
print(len(dict_paths))
``` | instruction | 0 | 65,489 | 1 | 130,978 |
No | output | 1 | 65,489 | 1 | 130,979 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
There are N islands lining up from west to east, connected by N-1 bridges.
The i-th bridge connects the i-th island from the west and the (i+1)-th island from the west.
One day, disputes took place between some islands, and there were M requests from the inhabitants of the islands:
Request i: A dispute took place between the a_i-th island from the west and the b_i-th island from the west. Please make traveling between these islands with bridges impossible.
You decided to remove some bridges to meet all these M requests.
Find the minimum number of bridges that must be removed.
Constraints
* All values in input are integers.
* 2 \leq N \leq 10^5
* 1 \leq M \leq 10^5
* 1 \leq a_i < b_i \leq N
* All pairs (a_i, b_i) are distinct.
Input
Input is given from Standard Input in the following format:
N M
a_1 b_1
a_2 b_2
:
a_M b_M
Output
Print the minimum number of bridges that must be removed.
Examples
Input
5 2
1 4
2 5
Output
1
Input
9 5
1 8
2 7
3 5
4 6
7 9
Output
2
Input
5 10
1 2
1 3
1 4
1 5
2 3
2 4
2 5
3 4
3 5
4 5
Output
4
Submitted Solution:
```
n, m = map(int, input().split())
ab = []
for i in range(m):
ab.append(list(map(int, input().split())))
ab.sort(reverse = True)
print(ab)
bridge = [float("inf")]
for i in range(m):
if ab[i][0] <= min(bridge) < ab[i][1]:
continue
else:
bridge.append(ab[i][0])
print(len(bridge) - 1)
``` | instruction | 0 | 65,490 | 1 | 130,980 |
No | output | 1 | 65,490 | 1 | 130,981 |
Provide tags and a correct Python 3 solution for this coding contest problem.
The government of Berland decided to improve network coverage in his country. Berland has a unique structure: the capital in the center and n cities in a circle around the capital. The capital already has a good network coverage (so the government ignores it), but the i-th city contains a_i households that require a connection.
The government designed a plan to build n network stations between all pairs of neighboring cities which will maintain connections only for these cities. In other words, the i-th network station will provide service only for the i-th and the (i + 1)-th city (the n-th station is connected to the n-th and the 1-st city).
All network stations have capacities: the i-th station can provide the connection to at most b_i households.
Now the government asks you to check can the designed stations meet the needs of all cities or not β that is, is it possible to assign each household a network station so that each network station i provides the connection to at most b_i households.
Input
The first line contains a single integer t (1 β€ t β€ 10^4) β the number of test cases.
The first line of each test case contains the single integer n (2 β€ n β€ 10^6) β the number of cities and stations.
The second line of each test case contains n integers (1 β€ a_i β€ 10^9) β the number of households in the i-th city.
The third line of each test case contains n integers (1 β€ b_i β€ 10^9) β the capacities of the designed stations.
It's guaranteed that the sum of n over test cases doesn't exceed 10^6.
Output
For each test case, print YES, if the designed stations can meet the needs of all cities, or NO otherwise (case insensitive).
Example
Input
5
3
2 3 4
3 3 3
3
3 3 3
2 3 4
4
2 3 4 5
3 7 2 2
4
4 5 2 3
2 3 2 7
2
1 1
10 10
Output
YES
YES
NO
YES
YES
Note
In the first test case:
* the first network station can provide 2 connections to the first city and 1 connection to the second city;
* the second station can provide 2 connections to the second city and 1 connection to the third city;
* the third station can provide 3 connections to the third city.
In the second test case:
* the 1-st station can provide 2 connections to the 1-st city;
* the 2-nd station can provide 3 connections to the 2-nd city;
* the 3-rd station can provide 3 connections to the 3-rd city and 1 connection to the 1-st station.
In the third test case, the fourth city needs 5 connections, but the third and the fourth station has 4 connections in total. | instruction | 0 | 65,754 | 1 | 131,508 |
Tags: binary search, constructive algorithms, data structures, greedy
Correct Solution:
```
import sys
input = sys.stdin.readline
def solve():
n = int(input())
A = list(map(int, input().split()))
B = list(map(int, input().split()))
lo = 0
hi = min(A[0], B[-1])+1
done = False
while lo < hi:
take = (lo + hi) // 2
avail = take
for i in range(n):
v = A[i]
ned = max(0, v - avail)
if i < n-1:
if B[i] < ned:
lo = take + 1
break
else:
if B[i] - take < ned:
hi = take
break
else:
print('YES')
return
avail = B[i] - ned
print('NO')
for _ in range(int(input())):
solve()
``` | output | 1 | 65,754 | 1 | 131,509 |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.