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Provide tags and a correct Python 3 solution for this coding contest problem. You are given an array of n integers a_1, a_2, ..., a_n, and a set b of k distinct integers from 1 to n. In one operation, you may choose two integers i and x (1 ≀ i ≀ n, x can be any integer) and assign a_i := x. This operation can be done only if i does not belong to the set b. Calculate the minimum number of operations you should perform so the array a is increasing (that is, a_1 < a_2 < a_3 < ... < a_n), or report that it is impossible. Input The first line contains two integers n and k (1 ≀ n ≀ 5 β‹… 10^5, 0 ≀ k ≀ n) β€” the size of the array a and the set b, respectively. The second line contains n integers a_1, a_2, ..., a_n (1 ≀ a_i ≀ 10^9). Then, if k β‰  0, the third line follows, containing k integers b_1, b_2, ..., b_k (1 ≀ b_1 < b_2 < ... < b_k ≀ n). If k = 0, this line is skipped. Output If it is impossible to make the array a increasing using the given operations, print -1. Otherwise, print one integer β€” the minimum number of operations you have to perform. Examples Input 7 2 1 2 1 1 3 5 1 3 5 Output 4 Input 3 3 1 3 2 1 2 3 Output -1 Input 5 0 4 3 1 2 3 Output 2 Input 10 3 1 3 5 6 12 9 8 10 13 15 2 4 9 Output 3
instruction
0
102,240
12
204,480
Tags: binary search, constructive algorithms, data structures, dp, implementation Correct Solution: ``` import bisect def mat(arr): n = len(arr) a = [] arr = [(arr[i] - i) for i in range(n)] for i in range(n): if (arr[i] < arr[0] or arr[i] > arr[n - 1]): continue k = bisect.bisect_right(a, arr[i]) if k == len(a): a.append(arr[i]) else: a[k] = arr[i] res = n - len(a) return res n, m = map(int, input().split()) num1 = list(map(int, input().split())) if m == 0: num2 = [] else: num2 = list(map(int, input().split())) num1 = [-10 ** 10] + num1 + [10 ** 10] num2 = [0] + num2 + [n + 1] sum = 0 ddd = 1 num = num1[0] tmp = num2[0] for i in num2[1:]: if i - tmp > num1[i] - num: ddd = 0 break sum += mat(num1[tmp:i + 1]) num = num1[i] tmp= i if ddd: print(sum) else: print(-1) ```
output
1
102,240
12
204,481
Provide tags and a correct Python 3 solution for this coding contest problem. You are given an array of n integers a_1, a_2, ..., a_n, and a set b of k distinct integers from 1 to n. In one operation, you may choose two integers i and x (1 ≀ i ≀ n, x can be any integer) and assign a_i := x. This operation can be done only if i does not belong to the set b. Calculate the minimum number of operations you should perform so the array a is increasing (that is, a_1 < a_2 < a_3 < ... < a_n), or report that it is impossible. Input The first line contains two integers n and k (1 ≀ n ≀ 5 β‹… 10^5, 0 ≀ k ≀ n) β€” the size of the array a and the set b, respectively. The second line contains n integers a_1, a_2, ..., a_n (1 ≀ a_i ≀ 10^9). Then, if k β‰  0, the third line follows, containing k integers b_1, b_2, ..., b_k (1 ≀ b_1 < b_2 < ... < b_k ≀ n). If k = 0, this line is skipped. Output If it is impossible to make the array a increasing using the given operations, print -1. Otherwise, print one integer β€” the minimum number of operations you have to perform. Examples Input 7 2 1 2 1 1 3 5 1 3 5 Output 4 Input 3 3 1 3 2 1 2 3 Output -1 Input 5 0 4 3 1 2 3 Output 2 Input 10 3 1 3 5 6 12 9 8 10 13 15 2 4 9 Output 3
instruction
0
102,241
12
204,482
Tags: binary search, constructive algorithms, data structures, dp, implementation Correct Solution: ``` from bisect import bisect_right INF = 10**9+1 n, k = map(int, input().split()) a = [-INF] + [ ai - i for i, ai in enumerate(map(int, input().split())) ] + [INF] b = [0] + (list(map(int, input().split())) if k else list()) + [n+1] ans = 0 for j in range(k+1): l = b[j] r = b[j+1] if a[r] < a[l]: print("-1") exit() lis = list() for ai in a[l+1:r]: if a[l] <= ai <= a[r]: pos = bisect_right(lis, ai) if pos == len(lis): lis.append(ai) else: lis[pos] = ai ans += r - l - 1 - len(lis) print(ans) ```
output
1
102,241
12
204,483
Provide tags and a correct Python 3 solution for this coding contest problem. You are given an array of n integers a_1, a_2, ..., a_n, and a set b of k distinct integers from 1 to n. In one operation, you may choose two integers i and x (1 ≀ i ≀ n, x can be any integer) and assign a_i := x. This operation can be done only if i does not belong to the set b. Calculate the minimum number of operations you should perform so the array a is increasing (that is, a_1 < a_2 < a_3 < ... < a_n), or report that it is impossible. Input The first line contains two integers n and k (1 ≀ n ≀ 5 β‹… 10^5, 0 ≀ k ≀ n) β€” the size of the array a and the set b, respectively. The second line contains n integers a_1, a_2, ..., a_n (1 ≀ a_i ≀ 10^9). Then, if k β‰  0, the third line follows, containing k integers b_1, b_2, ..., b_k (1 ≀ b_1 < b_2 < ... < b_k ≀ n). If k = 0, this line is skipped. Output If it is impossible to make the array a increasing using the given operations, print -1. Otherwise, print one integer β€” the minimum number of operations you have to perform. Examples Input 7 2 1 2 1 1 3 5 1 3 5 Output 4 Input 3 3 1 3 2 1 2 3 Output -1 Input 5 0 4 3 1 2 3 Output 2 Input 10 3 1 3 5 6 12 9 8 10 13 15 2 4 9 Output 3
instruction
0
102,242
12
204,484
Tags: binary search, constructive algorithms, data structures, dp, implementation Correct Solution: ``` import bisect def fun(arr): arr = [(arr[i] - i) for i in range(len(arr))] a = [] for i in range(len(arr)): if (arr[i] < arr[0] or arr[i] > arr[len(arr) - 1]): continue k = bisect.bisect_right(a, arr[i]) if k == len(a): a.append(arr[i]) else: a[k] = arr[i] result = len(arr) - len(a) return result n, k = map(int, input().split()) a = list(map(int, input().split())) if k == 0: b = [] else: b = list(map(int, input().split())) a = [-10 ** 10] + a + [10 ** 10] b = [0] + b + [n + 1] result = 0 flag = True t, temp = b[0], a[0] for i in b[1:]: if i - t > a[i] - temp: flag = False break result += fun(a[t:i + 1]) t, temp = i, a[i] if flag: print(result) else: print(-1) ```
output
1
102,242
12
204,485
Provide tags and a correct Python 3 solution for this coding contest problem. You are given an array of n integers a_1, a_2, ..., a_n, and a set b of k distinct integers from 1 to n. In one operation, you may choose two integers i and x (1 ≀ i ≀ n, x can be any integer) and assign a_i := x. This operation can be done only if i does not belong to the set b. Calculate the minimum number of operations you should perform so the array a is increasing (that is, a_1 < a_2 < a_3 < ... < a_n), or report that it is impossible. Input The first line contains two integers n and k (1 ≀ n ≀ 5 β‹… 10^5, 0 ≀ k ≀ n) β€” the size of the array a and the set b, respectively. The second line contains n integers a_1, a_2, ..., a_n (1 ≀ a_i ≀ 10^9). Then, if k β‰  0, the third line follows, containing k integers b_1, b_2, ..., b_k (1 ≀ b_1 < b_2 < ... < b_k ≀ n). If k = 0, this line is skipped. Output If it is impossible to make the array a increasing using the given operations, print -1. Otherwise, print one integer β€” the minimum number of operations you have to perform. Examples Input 7 2 1 2 1 1 3 5 1 3 5 Output 4 Input 3 3 1 3 2 1 2 3 Output -1 Input 5 0 4 3 1 2 3 Output 2 Input 10 3 1 3 5 6 12 9 8 10 13 15 2 4 9 Output 3
instruction
0
102,243
12
204,486
Tags: binary search, constructive algorithms, data structures, dp, implementation Correct Solution: ``` import bisect def calculate(num): aa=[] bb=[] n = len(num) num = [(num[i] - i) for i in range(0,n)] for i in range(0,n): if (num[i] > num[n - 1] or num[i] < num[0] ): continue kk = bisect.bisect_right(aa, num[i]) if kk != len(aa): aa[kk] = num[i] else: aa.append(num[i]) return (n - len(aa)) outt =1 n, k = map(int, input().split()) a1=[] a1 = list(map(int, input().split())) if k != 0: a2 = list(map(int, input().split())) else: a2 = [] a1 = [-10**10] + a1 + [10**10] a2 = [0]+ a2 + [n + 1] aa1= a1[0] aa2= a2[0] outt=0 flag = True for j in a2[1:]: if (j + aa1 > a1[j]+ aa2): flag = False break outt = outt+calculate(a1[aa2:j + 1]) aa1 =a1[j] aa2=j if (flag==False): print(-1) else: print(outt) ```
output
1
102,243
12
204,487
Provide tags and a correct Python 3 solution for this coding contest problem. You are given an array of n integers a_1, a_2, ..., a_n, and a set b of k distinct integers from 1 to n. In one operation, you may choose two integers i and x (1 ≀ i ≀ n, x can be any integer) and assign a_i := x. This operation can be done only if i does not belong to the set b. Calculate the minimum number of operations you should perform so the array a is increasing (that is, a_1 < a_2 < a_3 < ... < a_n), or report that it is impossible. Input The first line contains two integers n and k (1 ≀ n ≀ 5 β‹… 10^5, 0 ≀ k ≀ n) β€” the size of the array a and the set b, respectively. The second line contains n integers a_1, a_2, ..., a_n (1 ≀ a_i ≀ 10^9). Then, if k β‰  0, the third line follows, containing k integers b_1, b_2, ..., b_k (1 ≀ b_1 < b_2 < ... < b_k ≀ n). If k = 0, this line is skipped. Output If it is impossible to make the array a increasing using the given operations, print -1. Otherwise, print one integer β€” the minimum number of operations you have to perform. Examples Input 7 2 1 2 1 1 3 5 1 3 5 Output 4 Input 3 3 1 3 2 1 2 3 Output -1 Input 5 0 4 3 1 2 3 Output 2 Input 10 3 1 3 5 6 12 9 8 10 13 15 2 4 9 Output 3
instruction
0
102,244
12
204,488
Tags: binary search, constructive algorithms, data structures, dp, implementation Correct Solution: ``` import bisect def TSort(): one=False zero=False flag=True for i in range(0,n): if i<n-1: if a[i+1]<a[i]: flag=False if b[i]==0: one=True else: zero=True if flag or (one and zero): print("Yes") else: print("No") def snynb(arr): n = len(arr) a = [] arr = [(arr[i] - i) for i in range(n)] for i in range(n): if (arr[i] < arr[0] or arr[i] > arr[n - 1]): continue k = bisect.bisect_right(a, arr[i]) if k == len(a): a.append(arr[i]) else: a[k] = arr[i] x = n - len(a) return x def okk(mid): global n,shuzu,k,m m=0 zonghe=0 cnt=0 for i in range (n): if zonghe+shuzu[i]>=mid: if zonghe>m: m=zonghe zonghe=shuzu[i] cnt=cnt+1 else: zonghe=zonghe+shuzu[i] return cnt<k n, m = map(int, input().split()) num1 = list(map(int, input().split())) if m == 0: num2 = [] else: num2 = list(map(int, input().split())) num1 = [-10 ** 10] + num1 + [10 ** 10] num2 = [0] + num2 + [n + 1] sum = 0 sny = 1 num = num1[0] t = num2[0] for i in num2[1:]: if i - t > num1[i] - num: sny = 0 break sum += snynb(num1[t:i + 1]) num = num1[i] t = i if sny: print(sum) else: print(-1) ```
output
1
102,244
12
204,489
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. You are given an array of n integers a_1, a_2, ..., a_n, and a set b of k distinct integers from 1 to n. In one operation, you may choose two integers i and x (1 ≀ i ≀ n, x can be any integer) and assign a_i := x. This operation can be done only if i does not belong to the set b. Calculate the minimum number of operations you should perform so the array a is increasing (that is, a_1 < a_2 < a_3 < ... < a_n), or report that it is impossible. Input The first line contains two integers n and k (1 ≀ n ≀ 5 β‹… 10^5, 0 ≀ k ≀ n) β€” the size of the array a and the set b, respectively. The second line contains n integers a_1, a_2, ..., a_n (1 ≀ a_i ≀ 10^9). Then, if k β‰  0, the third line follows, containing k integers b_1, b_2, ..., b_k (1 ≀ b_1 < b_2 < ... < b_k ≀ n). If k = 0, this line is skipped. Output If it is impossible to make the array a increasing using the given operations, print -1. Otherwise, print one integer β€” the minimum number of operations you have to perform. Examples Input 7 2 1 2 1 1 3 5 1 3 5 Output 4 Input 3 3 1 3 2 1 2 3 Output -1 Input 5 0 4 3 1 2 3 Output 2 Input 10 3 1 3 5 6 12 9 8 10 13 15 2 4 9 Output 3 Submitted Solution: ``` import sys import math from bisect import bisect_right def II(): return int(sys.stdin.readline()) def LI(): return list(map(int, sys.stdin.readline().split())) def MI(): return map(int, sys.stdin.readline().split()) def SI(): return sys.stdin.readline().strip() n,k = MI() a = LI() a = [float('-inf')]+a+[float('inf')] b = [] if k!=0: b = LI() b = [0]+b+[n+1] ans = n-k for i in range(k+1): l = b[i] r = b[i+1] if a[l]-l>a[r]-r: print(-1) exit(0) lis = [] for j in range(l+1,r): if not a[l]-l<=a[j]-j<=a[r]-r: continue ind = bisect_right(lis,a[j]-j) if ind == len(lis): lis.append(a[j]-j) else: lis[ind] = a[j]-j ans-=len(lis) print(ans) ```
instruction
0
102,247
12
204,494
Yes
output
1
102,247
12
204,495
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. You are given an array of n integers a_1, a_2, ..., a_n, and a set b of k distinct integers from 1 to n. In one operation, you may choose two integers i and x (1 ≀ i ≀ n, x can be any integer) and assign a_i := x. This operation can be done only if i does not belong to the set b. Calculate the minimum number of operations you should perform so the array a is increasing (that is, a_1 < a_2 < a_3 < ... < a_n), or report that it is impossible. Input The first line contains two integers n and k (1 ≀ n ≀ 5 β‹… 10^5, 0 ≀ k ≀ n) β€” the size of the array a and the set b, respectively. The second line contains n integers a_1, a_2, ..., a_n (1 ≀ a_i ≀ 10^9). Then, if k β‰  0, the third line follows, containing k integers b_1, b_2, ..., b_k (1 ≀ b_1 < b_2 < ... < b_k ≀ n). If k = 0, this line is skipped. Output If it is impossible to make the array a increasing using the given operations, print -1. Otherwise, print one integer β€” the minimum number of operations you have to perform. Examples Input 7 2 1 2 1 1 3 5 1 3 5 Output 4 Input 3 3 1 3 2 1 2 3 Output -1 Input 5 0 4 3 1 2 3 Output 2 Input 10 3 1 3 5 6 12 9 8 10 13 15 2 4 9 Output 3 Submitted Solution: ``` import bisect def solve(numss): n = len(numss) a = [] numss = [(numss[i] - i) for i in range(n)] for i in range(n): if (numss[i] < numss[0] or numss[i] > numss[n - 1]): continue k = bisect.bisect_right(a, numss[i]) if k == len(a): a.append(numss[i]) else: a[k] = numss[i] res = n - len(a) return res def main(): n, k = map(int, input().split()) a = list(map(int, input().split())) if k == 0: b = [] else: b = list(map(int, input().split())) a = [-10 ** 10] + a + [10 ** 10] b = [0] + b + [n + 1] res = 0 ok = True t, tp = b[0], a[0] for i in b[1:]: if i - t > a[i] - tp: ok = False break res += solve(a[t:i + 1]) t, tp = i, a[i] if ok: print(res) else: print(-1) if __name__ == '__main__': main() ```
instruction
0
102,248
12
204,496
Yes
output
1
102,248
12
204,497
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. You are given an array of n integers a_1, a_2, ..., a_n, and a set b of k distinct integers from 1 to n. In one operation, you may choose two integers i and x (1 ≀ i ≀ n, x can be any integer) and assign a_i := x. This operation can be done only if i does not belong to the set b. Calculate the minimum number of operations you should perform so the array a is increasing (that is, a_1 < a_2 < a_3 < ... < a_n), or report that it is impossible. Input The first line contains two integers n and k (1 ≀ n ≀ 5 β‹… 10^5, 0 ≀ k ≀ n) β€” the size of the array a and the set b, respectively. The second line contains n integers a_1, a_2, ..., a_n (1 ≀ a_i ≀ 10^9). Then, if k β‰  0, the third line follows, containing k integers b_1, b_2, ..., b_k (1 ≀ b_1 < b_2 < ... < b_k ≀ n). If k = 0, this line is skipped. Output If it is impossible to make the array a increasing using the given operations, print -1. Otherwise, print one integer β€” the minimum number of operations you have to perform. Examples Input 7 2 1 2 1 1 3 5 1 3 5 Output 4 Input 3 3 1 3 2 1 2 3 Output -1 Input 5 0 4 3 1 2 3 Output 2 Input 10 3 1 3 5 6 12 9 8 10 13 15 2 4 9 Output 3 Submitted Solution: ``` import sys,os,io input = sys.stdin.readline from bisect import bisect_right N, K = map(int, input().split()) A = [-float('inf')]+list(map(int, input().split()))+[float('inf')] if K: B = [0]+list(map(int, input().split()))+[N+1] else: B = [0,N+1] ans = N-K for k in range(K+1): left, right = B[k], B[k+1] if A[left]>=A[right]: print(-1) break lis = [] for i in range(left+1,right): if not A[left]-left<=A[i]-i<=A[right]-right: continue ind = bisect_right(lis,A[i]-i) if ind == len(lis): lis.append(A[i]-i) else: lis[ind] = A[i]-i ans -= len(lis) else: print(ans) ```
instruction
0
102,249
12
204,498
No
output
1
102,249
12
204,499
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. You are given an array of n integers a_1, a_2, ..., a_n, and a set b of k distinct integers from 1 to n. In one operation, you may choose two integers i and x (1 ≀ i ≀ n, x can be any integer) and assign a_i := x. This operation can be done only if i does not belong to the set b. Calculate the minimum number of operations you should perform so the array a is increasing (that is, a_1 < a_2 < a_3 < ... < a_n), or report that it is impossible. Input The first line contains two integers n and k (1 ≀ n ≀ 5 β‹… 10^5, 0 ≀ k ≀ n) β€” the size of the array a and the set b, respectively. The second line contains n integers a_1, a_2, ..., a_n (1 ≀ a_i ≀ 10^9). Then, if k β‰  0, the third line follows, containing k integers b_1, b_2, ..., b_k (1 ≀ b_1 < b_2 < ... < b_k ≀ n). If k = 0, this line is skipped. Output If it is impossible to make the array a increasing using the given operations, print -1. Otherwise, print one integer β€” the minimum number of operations you have to perform. Examples Input 7 2 1 2 1 1 3 5 1 3 5 Output 4 Input 3 3 1 3 2 1 2 3 Output -1 Input 5 0 4 3 1 2 3 Output 2 Input 10 3 1 3 5 6 12 9 8 10 13 15 2 4 9 Output 3 Submitted Solution: ``` import bisect one, two = map(int, input().split()) arr = list(map(int, input().split())) if two == 0: second = list() else: second = list(map(int, input().split())) res = 0 second = [0] + second + [one + 1] count = second[0] num = arr[0] arr = [-10 ** 10] + arr + [10 ** 10] flag = 1 def judge(num): n = len(num) ls = list() num = [(num[i] - i) for i in range(n)] for i in range(n): if (num[i] < num[0] or num[i] > num[n - 1]): continue k = bisect.bisect_right(ls, num[i]) if k == len(ls): ls.append(num[i]) else: ls[k] = num[i] ans = n - len(ls) return ans for j in second[1:]: if j - count > arr[j] - num: flag = 0 break res += judge(arr[count:j + 1]) count, num = j, arr[j] if flag: print(res) else: print(-1) ```
instruction
0
102,251
12
204,502
No
output
1
102,251
12
204,503
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. You are given an array of n integers a_1, a_2, ..., a_n, and a set b of k distinct integers from 1 to n. In one operation, you may choose two integers i and x (1 ≀ i ≀ n, x can be any integer) and assign a_i := x. This operation can be done only if i does not belong to the set b. Calculate the minimum number of operations you should perform so the array a is increasing (that is, a_1 < a_2 < a_3 < ... < a_n), or report that it is impossible. Input The first line contains two integers n and k (1 ≀ n ≀ 5 β‹… 10^5, 0 ≀ k ≀ n) β€” the size of the array a and the set b, respectively. The second line contains n integers a_1, a_2, ..., a_n (1 ≀ a_i ≀ 10^9). Then, if k β‰  0, the third line follows, containing k integers b_1, b_2, ..., b_k (1 ≀ b_1 < b_2 < ... < b_k ≀ n). If k = 0, this line is skipped. Output If it is impossible to make the array a increasing using the given operations, print -1. Otherwise, print one integer β€” the minimum number of operations you have to perform. Examples Input 7 2 1 2 1 1 3 5 1 3 5 Output 4 Input 3 3 1 3 2 1 2 3 Output -1 Input 5 0 4 3 1 2 3 Output 2 Input 10 3 1 3 5 6 12 9 8 10 13 15 2 4 9 Output 3 Submitted Solution: ``` import sys, math import io, os #data = io.BytesIO(os.read(0,os.fstat(0).st_size)).readline from bisect import bisect_left as bl, bisect_right as br, insort from heapq import heapify, heappush, heappop from collections import defaultdict as dd, deque, Counter from itertools import permutations,combinations def data(): return sys.stdin.readline().strip() def mdata(): return list(map(int, data().split())) def outl(var) : sys.stdout.write(' '.join(map(str, var))+'\n') def out(var) : sys.stdout.write(str(var)+'\n') #from decimal import Decimal #from fractions import Fraction #sys.setrecursionlimit(100000) INF = 10**9 mod = int(1e9)+7 def CeilIndex(A, l, r, key): while (r - l > 1): m = l + (r - l) // 2 if (A[m] >= key): r = m else: l = m return r def LongestIncreasingSubsequenceLength(A, size, s, e): tailTable = [0 for i in range(e-s+1)] ind = [0 for i in range(e-s+1)] len = 0 tailTable[0] = A[s] ind[0] = s len = 1 for i in range(s+1, e): if A[s]+i-s<=A[i]<=A[e]+i-e : if (A[i] > tailTable[len - 1]): if i-ind[len-1]<=A[i]-tailTable[len - 1]: tailTable[len] = A[i] ind[len] = i len += 1 else: ind1=CeilIndex(tailTable, -1, len - 1, A[i]) if i-ind[ind1]<=A[i]-tailTable[ind1 - 1]: tailTable[ind1] = A[i] ind[ind1]=i return len-1 n,k=mdata() a=[-INF]+mdata()+[INF] b=[0] if k: b+=sorted(mdata()) b+=[n+1] for i in range(k+1): if a[b[i+1]]-a[b[i]]<b[i+1]-b[i]: out(-1) exit() ans=0 for i in range(k+1): ans+=b[i+1]-b[i]-1-LongestIncreasingSubsequenceLength(a,n+2,b[i],b[i+1]) out(ans) ```
instruction
0
102,252
12
204,504
No
output
1
102,252
12
204,505
Provide tags and a correct Python 3 solution for this coding contest problem. Jeff's friends know full well that the boy likes to get sequences and arrays for his birthday. Thus, Jeff got sequence p1, p2, ..., pn for his birthday. Jeff hates inversions in sequences. An inversion in sequence a1, a2, ..., an is a pair of indexes i, j (1 ≀ i < j ≀ n), such that an inequality ai > aj holds. Jeff can multiply some numbers of the sequence p by -1. At that, he wants the number of inversions in the sequence to be minimum. Help Jeff and find the minimum number of inversions he manages to get. Input The first line contains integer n (1 ≀ n ≀ 2000). The next line contains n integers β€” sequence p1, p2, ..., pn (|pi| ≀ 105). The numbers are separated by spaces. Output In a single line print the answer to the problem β€” the minimum number of inversions Jeff can get. Examples Input 2 2 1 Output 0 Input 9 -2 0 -1 0 -1 2 1 0 -1 Output 6
instruction
0
102,399
12
204,798
Tags: greedy Correct Solution: ``` n = int(input()) inp = input() seq = inp.split(' ') seq = [ abs(int(x)) for x in seq ] Max = max(seq) nxt = [0] * n cnt = [0] * n pos = [n] * (Max+1) for i in range(n-1, -1, -1): nxt[i] = pos[seq[i]] pos[seq[i]] = i for i in range(0, Max+1): j = pos[i] while(j<n): front = sum(cnt[0:j]) back = sum(cnt[j+1:n]) if(front < back): seq[j] = 0 - seq[j] j = nxt[j] j = pos[i] while(j < n): cnt[j] = 1 j = nxt[j] #for i in range(0, n-1): # print(seq[i], sep=' ') #print(seq[n-1]) inv = 0 for i in range(len(seq)): for j in range(i+1, len(seq)): if(seq[i] > seq[j]): inv += 1 print(inv) ```
output
1
102,399
12
204,799
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. Jeff's friends know full well that the boy likes to get sequences and arrays for his birthday. Thus, Jeff got sequence p1, p2, ..., pn for his birthday. Jeff hates inversions in sequences. An inversion in sequence a1, a2, ..., an is a pair of indexes i, j (1 ≀ i < j ≀ n), such that an inequality ai > aj holds. Jeff can multiply some numbers of the sequence p by -1. At that, he wants the number of inversions in the sequence to be minimum. Help Jeff and find the minimum number of inversions he manages to get. Input The first line contains integer n (1 ≀ n ≀ 2000). The next line contains n integers β€” sequence p1, p2, ..., pn (|pi| ≀ 105). The numbers are separated by spaces. Output In a single line print the answer to the problem β€” the minimum number of inversions Jeff can get. Examples Input 2 2 1 Output 0 Input 9 -2 0 -1 0 -1 2 1 0 -1 Output 6 Submitted Solution: ``` print("QUE TE CACHEN PROBLEMA E(DIV1)") print("By: GUillermo Montanez Sosa - Guillermo_0114") ```
instruction
0
102,400
12
204,800
No
output
1
102,400
12
204,801
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. Jeff's friends know full well that the boy likes to get sequences and arrays for his birthday. Thus, Jeff got sequence p1, p2, ..., pn for his birthday. Jeff hates inversions in sequences. An inversion in sequence a1, a2, ..., an is a pair of indexes i, j (1 ≀ i < j ≀ n), such that an inequality ai > aj holds. Jeff can multiply some numbers of the sequence p by -1. At that, he wants the number of inversions in the sequence to be minimum. Help Jeff and find the minimum number of inversions he manages to get. Input The first line contains integer n (1 ≀ n ≀ 2000). The next line contains n integers β€” sequence p1, p2, ..., pn (|pi| ≀ 105). The numbers are separated by spaces. Output In a single line print the answer to the problem β€” the minimum number of inversions Jeff can get. Examples Input 2 2 1 Output 0 Input 9 -2 0 -1 0 -1 2 1 0 -1 Output 6 Submitted Solution: ``` n = int(input()) inp = input() seq = inp.split(' ') seq = [ abs(int(x)) for x in seq ] Max = max(seq) nxt = [0] * n cnt = [0] * n pos = [n] * (Max+1) for i in range(n-1, -1, -1): nxt[i] = pos[seq[i]] pos[seq[i]] = i for i in range(0, Max+1): j = pos[i] while(j<n): front = sum(cnt[0:j]) back = sum(cnt[j+1:n]) if(front < back): seq[j] = 0 - seq[j] cnt[j] = 1 j = nxt[j] #for i in range(0, n-1): # print(seq[i], sep=' ') #print(seq[n-1]) inv = 0 for i in range(len(seq)): for j in range(i+1, len(seq)): if(seq[i] > seq[j]): inv += 1 print(inv) ```
instruction
0
102,401
12
204,802
No
output
1
102,401
12
204,803
Provide tags and a correct Python 3 solution for this coding contest problem. For a sequence a of n integers between 1 and m, inclusive, denote f(a) as the number of distinct subsequences of a (including the empty subsequence). You are given two positive integers n and m. Let S be the set of all sequences of length n consisting of numbers from 1 to m. Compute the sum f(a) over all a in S modulo 109 + 7. Input The only line contains two integers n and m (1 ≀ n, m ≀ 106) β€” the number of elements in arrays and the upper bound for elements. Output Print the only integer c β€” the desired sum modulo 109 + 7. Examples Input 1 3 Output 6 Input 2 2 Output 14 Input 3 3 Output 174
instruction
0
102,522
12
205,044
Tags: combinatorics Correct Solution: ``` p = 10**9+7 n, m = map(int, input().split()) print (n+1 if m == 1 else pow(m, n, p)*(1+(pow(2*m-1, n, p)*pow(m, p-1-n, p) - 1)*m*pow(m-1, p-2, p))%p) ```
output
1
102,522
12
205,045
Provide tags and a correct Python 3 solution for this coding contest problem. For a sequence a of n integers between 1 and m, inclusive, denote f(a) as the number of distinct subsequences of a (including the empty subsequence). You are given two positive integers n and m. Let S be the set of all sequences of length n consisting of numbers from 1 to m. Compute the sum f(a) over all a in S modulo 109 + 7. Input The only line contains two integers n and m (1 ≀ n, m ≀ 106) β€” the number of elements in arrays and the upper bound for elements. Output Print the only integer c β€” the desired sum modulo 109 + 7. Examples Input 1 3 Output 6 Input 2 2 Output 14 Input 3 3 Output 174
instruction
0
102,523
12
205,046
Tags: combinatorics Correct Solution: ``` #### IMPORTANT LIBRARY #### ############################ ### DO NOT USE import random --> 250ms to load the library ############################ ### In case of extra libraries: https://github.com/cheran-senthil/PyRival ###################### ####### IMPORT ####### ###################### from functools import cmp_to_key from collections import deque, Counter from heapq import heappush, heappop from math import log, ceil ###################### #### STANDARD I/O #### ###################### import sys import os from io import BytesIO, IOBase 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") if sys.version_info[0] < 3: sys.stdin, sys.stdout = FastIO(sys.stdin), FastIO(sys.stdout) else: sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout) def print(*args, **kwargs): sep, file = kwargs.pop("sep", " "), kwargs.pop("file", sys.stdout) at_start = True for x in args: if not at_start: file.write(sep) file.write(str(x)) at_start = False file.write(kwargs.pop("end", "\n")) if kwargs.pop("flush", False): file.flush() def inp(): return sys.stdin.readline().rstrip("\r\n") # for fast input def ii(): return int(inp()) def si(): return str(inp()) def li(lag = 0): l = list(map(int, inp().split())) if lag != 0: for i in range(len(l)): l[i] += lag return l def mi(lag = 0): matrix = list() for i in range(n): matrix.append(li(lag)) return matrix def lsi(): #string list return list(map(str, inp().split())) def print_list(lista, space = " "): print(space.join(map(str, lista))) ###################### ### BISECT METHODS ### ###################### def bisect_left(a, x): """i tale che a[i] >= x e a[i-1] < x""" left = 0 right = len(a) while left < right: mid = (left+right)//2 if a[mid] < x: left = mid+1 else: right = mid return left def bisect_right(a, x): """i tale che a[i] > x e a[i-1] <= x""" left = 0 right = len(a) while left < right: mid = (left+right)//2 if a[mid] > x: right = mid else: left = mid+1 return left def bisect_elements(a, x): """elementi pari a x nell'Γ‘rray sortato""" return bisect_right(a, x) - bisect_left(a, x) ###################### ### MOD OPERATION #### ###################### MOD = 10**9 + 7 maxN = 5 FACT = [0] * maxN INV_FACT = [0] * maxN def add(x, y): return (x+y) % MOD def multiply(x, y): return (x*y) % MOD def power(x, y): if y == 0: return 1 elif y % 2: return multiply(x, power(x, y-1)) else: a = power(x, y//2) return multiply(a, a) def inverse(x): return power(x, MOD-2) def divide(x, y): return multiply(x, inverse(y)) def allFactorials(): FACT[0] = 1 for i in range(1, maxN): FACT[i] = multiply(i, FACT[i-1]) def inverseFactorials(): n = len(INV_FACT) INV_FACT[n-1] = inverse(FACT[n-1]) for i in range(n-2, -1, -1): INV_FACT[i] = multiply(INV_FACT[i+1], i+1) def coeffBinom(n, k): if n < k: return 0 return multiply(FACT[n], multiply(INV_FACT[k], INV_FACT[n-k])) ###################### #### GRAPH ALGOS ##### ###################### # ZERO BASED GRAPH def create_graph(n, m, undirected = 1, unweighted = 1): graph = [[] for i in range(n)] if unweighted: for i in range(m): [x, y] = li(lag = -1) graph[x].append(y) if undirected: graph[y].append(x) else: for i in range(m): [x, y, w] = li(lag = -1) w += 1 graph[x].append([y,w]) if undirected: graph[y].append([x,w]) return graph def create_tree(n, unweighted = 1): children = [[] for i in range(n)] if unweighted: for i in range(n-1): [x, y] = li(lag = -1) children[x].append(y) children[y].append(x) else: for i in range(n-1): [x, y, w] = li(lag = -1) w += 1 children[x].append([y, w]) children[y].append([x, w]) return children def dist(tree, n, A, B = -1): s = [[A, 0]] massimo, massimo_nodo = 0, 0 distanza = -1 v = [-1] * n while s: el, dis = s.pop() if dis > massimo: massimo = dis massimo_nodo = el if el == B: distanza = dis for child in tree[el]: if v[child] == -1: v[child] = 1 s.append([child, dis+1]) return massimo, massimo_nodo, distanza def diameter(tree): _, foglia, _ = dist(tree, n, 0) diam, _, _ = dist(tree, n, foglia) return diam def dfs(graph, n, A): v = [-1] * n s = [[A, 0]] v[A] = 0 while s: el, dis = s.pop() for child in graph[el]: if v[child] == -1: v[child] = dis + 1 s.append([child, dis + 1]) return v #visited: -1 if not visited, otherwise v[B] is the distance in terms of edges def bfs(graph, n, A): v = [-1] * n s = deque() s.append([A, 0]) v[A] = 0 while s: el, dis = s.popleft() for child in graph[el]: if v[child] == -1: v[child] = dis + 1 s.append([child, dis + 1]) return v #visited: -1 if not visited, otherwise v[B] is the distance in terms of edges #FROM A GIVEN ROOT, RECOVER THE STRUCTURE def parents_children_root_unrooted_tree(tree, n, root = 0): q = deque() visited = [0] * n parent = [-1] * n children = [[] for i in range(n)] q.append(root) while q: all_done = 1 visited[q[0]] = 1 for child in tree[q[0]]: if not visited[child]: all_done = 0 q.appendleft(child) if all_done: for child in tree[q[0]]: if parent[child] == -1: parent[q[0]] = child children[child].append(q[0]) q.popleft() return parent, children # CALCULATING LONGEST PATH FOR ALL THE NODES def all_longest_path_passing_from_node(parent, children, n): q = deque() visited = [len(children[i]) for i in range(n)] downwards = [[0,0] for i in range(n)] upward = [1] * n longest_path = [1] * n for i in range(n): if not visited[i]: q.append(i) downwards[i] = [1,0] while q: node = q.popleft() if parent[node] != -1: visited[parent[node]] -= 1 if not visited[parent[node]]: q.append(parent[node]) else: root = node for child in children[node]: downwards[node] = sorted([downwards[node][0], downwards[node][1], downwards[child][0] + 1], reverse = True)[0:2] s = [node] while s: node = s.pop() if parent[node] != -1: if downwards[parent[node]][0] == downwards[node][0] + 1: upward[node] = 1 + max(upward[parent[node]], downwards[parent[node]][1]) else: upward[node] = 1 + max(upward[parent[node]], downwards[parent[node]][0]) longest_path[node] = downwards[node][0] + downwards[node][1] + upward[node] - min([downwards[node][0], downwards[node][1], upward[node]]) - 1 for child in children[node]: s.append(child) return longest_path ### TBD SUCCESSOR GRAPH 7.5 ### TBD TREE QUERIES 10.2 da 2 a 4 ### TBD ADVANCED TREE 10.3 ### TBD GRAPHS AND MATRICES 11.3.3 e 11.4.3 e 11.5.3 (ON GAMES) ###################### ## END OF LIBRARIES ## ###################### n,m = li() s = power(m, n) A = [m] B = [1] for i in range(n-1): A.append(multiply(A[-1], m)) B.append(multiply(B[-1], 2*m-1)) A.reverse() for i in range(n): k = multiply(A[i], B[i]) s = add(s, k) print(s) ```
output
1
102,523
12
205,047
Provide tags and a correct Python 3 solution for this coding contest problem. For a sequence a of n integers between 1 and m, inclusive, denote f(a) as the number of distinct subsequences of a (including the empty subsequence). You are given two positive integers n and m. Let S be the set of all sequences of length n consisting of numbers from 1 to m. Compute the sum f(a) over all a in S modulo 109 + 7. Input The only line contains two integers n and m (1 ≀ n, m ≀ 106) β€” the number of elements in arrays and the upper bound for elements. Output Print the only integer c β€” the desired sum modulo 109 + 7. Examples Input 1 3 Output 6 Input 2 2 Output 14 Input 3 3 Output 174
instruction
0
102,524
12
205,048
Tags: combinatorics Correct Solution: ``` import sys from array import array n, m = map(int, input().split()) dp = [array('i', [0])*(n+1) for _ in range(2)] dp[0][0] = dp[1][0] = 1 mod = 10**9 + 7 for i in range(1, n+1): dp[0][i] = (dp[0][i-1] * m + dp[0][i-1] * (m-1)) % mod dp[1][i] = (dp[0][i-1] * m + dp[1][i-1] * m) % mod print(dp[1][-1]) ```
output
1
102,524
12
205,049
Provide tags and a correct Python 3 solution for this coding contest problem. For a sequence a of n integers between 1 and m, inclusive, denote f(a) as the number of distinct subsequences of a (including the empty subsequence). You are given two positive integers n and m. Let S be the set of all sequences of length n consisting of numbers from 1 to m. Compute the sum f(a) over all a in S modulo 109 + 7. Input The only line contains two integers n and m (1 ≀ n, m ≀ 106) β€” the number of elements in arrays and the upper bound for elements. Output Print the only integer c β€” the desired sum modulo 109 + 7. Examples Input 1 3 Output 6 Input 2 2 Output 14 Input 3 3 Output 174
instruction
0
102,525
12
205,050
Tags: combinatorics Correct Solution: ``` n, m = map(int, input().split()) M = 1000000007 if m == 1: print(n + 1) else: print((m * pow(2 * m - 1, n, M) - pow(m, n, M)) * pow(m - 1, M - 2, M) % M) ```
output
1
102,525
12
205,051
Provide tags and a correct Python 3 solution for this coding contest problem. For a sequence a of n integers between 1 and m, inclusive, denote f(a) as the number of distinct subsequences of a (including the empty subsequence). You are given two positive integers n and m. Let S be the set of all sequences of length n consisting of numbers from 1 to m. Compute the sum f(a) over all a in S modulo 109 + 7. Input The only line contains two integers n and m (1 ≀ n, m ≀ 106) β€” the number of elements in arrays and the upper bound for elements. Output Print the only integer c β€” the desired sum modulo 109 + 7. Examples Input 1 3 Output 6 Input 2 2 Output 14 Input 3 3 Output 174
instruction
0
102,526
12
205,052
Tags: combinatorics Correct Solution: ``` n,m=map(int,input().split()) x,y,M=0,1,10**9+7 while n>0: x,y,n=(2*m*x-x+y)%M,y*m%M,n-1 print((y+m*x)%M) ```
output
1
102,526
12
205,053
Provide tags and a correct Python 3 solution for this coding contest problem. For a sequence a of n integers between 1 and m, inclusive, denote f(a) as the number of distinct subsequences of a (including the empty subsequence). You are given two positive integers n and m. Let S be the set of all sequences of length n consisting of numbers from 1 to m. Compute the sum f(a) over all a in S modulo 109 + 7. Input The only line contains two integers n and m (1 ≀ n, m ≀ 106) β€” the number of elements in arrays and the upper bound for elements. Output Print the only integer c β€” the desired sum modulo 109 + 7. Examples Input 1 3 Output 6 Input 2 2 Output 14 Input 3 3 Output 174
instruction
0
102,527
12
205,054
Tags: combinatorics Correct Solution: ``` n,m=map(int,input().split()) x,y,M=0,1,1000000007 for i in range(n): x=((2*m-1)*x+y)%M;y=y*m%M print((y+m*x)%M) ```
output
1
102,527
12
205,055
Provide tags and a correct Python 3 solution for this coding contest problem. For a sequence a of n integers between 1 and m, inclusive, denote f(a) as the number of distinct subsequences of a (including the empty subsequence). You are given two positive integers n and m. Let S be the set of all sequences of length n consisting of numbers from 1 to m. Compute the sum f(a) over all a in S modulo 109 + 7. Input The only line contains two integers n and m (1 ≀ n, m ≀ 106) β€” the number of elements in arrays and the upper bound for elements. Output Print the only integer c β€” the desired sum modulo 109 + 7. Examples Input 1 3 Output 6 Input 2 2 Output 14 Input 3 3 Output 174
instruction
0
102,528
12
205,056
Tags: combinatorics Correct Solution: ``` P = 10**9 + 7 n, k = map(int, input().split()) print(n + 1 if k == 1 else (k * pow(2 * k - 1, n, P) - pow(k, n, P)) * pow(k - 1, P - 2, P) % P) ```
output
1
102,528
12
205,057
Provide tags and a correct Python 3 solution for this coding contest problem. For a sequence a of n integers between 1 and m, inclusive, denote f(a) as the number of distinct subsequences of a (including the empty subsequence). You are given two positive integers n and m. Let S be the set of all sequences of length n consisting of numbers from 1 to m. Compute the sum f(a) over all a in S modulo 109 + 7. Input The only line contains two integers n and m (1 ≀ n, m ≀ 106) β€” the number of elements in arrays and the upper bound for elements. Output Print the only integer c β€” the desired sum modulo 109 + 7. Examples Input 1 3 Output 6 Input 2 2 Output 14 Input 3 3 Output 174
instruction
0
102,529
12
205,058
Tags: combinatorics Correct Solution: ``` import math def euclid_algorithm(a, b): t1, t2 = abs(a), abs(b) #saving equalities: #t1 == x1 * a + y1 * b, #t2 == x2 * a + y2 * b. x1, y1, x2, y2 = int(math.copysign(1, a)), 0, 0, int(math.copysign(1, b)) if t1 < t2: t1, t2 = t2, t1 x1, y1, x2, y2 = x2, y2, x1, y1 while t2 > 0: k = int(t1 // t2) t1, t2 = t2, t1 % t2 #t1 - k * t2 == (x1 - k * x2) * a + (y1 - k * y2) * b x1, y1, x2, y2 = x2, y2, x1 - k * x2, y1 - k * y2 return t1, x1, y1 def opposite_element(x, p): gcd, k, l = euclid_algorithm(x, p) if gcd != 1: return -1 return k % p def solve(n, m, p): if (m-1) % p == 0: return (n + 1) * pow(m, n, p) % p else: S = pow(m, n, p) k = opposite_element(m, p) l = (2*m - 1) * k % p q = opposite_element(l - 1, p) S += pow(m, n, p) * (pow(l, n, p) - 1) * q S %= p return S p = 10 ** 9 + 7 n, m = [int(x) for x in input().split()] print(solve(n, m, p)) ```
output
1
102,529
12
205,059
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. For a sequence a of n integers between 1 and m, inclusive, denote f(a) as the number of distinct subsequences of a (including the empty subsequence). You are given two positive integers n and m. Let S be the set of all sequences of length n consisting of numbers from 1 to m. Compute the sum f(a) over all a in S modulo 109 + 7. Input The only line contains two integers n and m (1 ≀ n, m ≀ 106) β€” the number of elements in arrays and the upper bound for elements. Output Print the only integer c β€” the desired sum modulo 109 + 7. Examples Input 1 3 Output 6 Input 2 2 Output 14 Input 3 3 Output 174 Submitted Solution: ``` import math def euclid_algorithm(a, b): t1, t2 = abs(a), abs(b) #saving equalities: #t1 == x1 * a + y1 * b, #t2 == x2 * a + y2 * b. x1, y1, x2, y2 = int(math.copysign(1, a)), 0, 0, int(math.copysign(1, b)) if t1 < t2: t1, t2 = t2, t1 x1, y1, x2, y2 = x2, y2, x1, y1 while t2 > 0: k = int(t1 // t2) t1, t2 = t2, t1 % t2 #t1 - k * t2 == (x1 - k * x2) * a + (y1 - k * y2) * b x1, y1, x2, y2 = x2, y2, x1 - k * x2, y1 - k * y2 return t1, x1, y1 def opposite_element(x, p): gcd, k, l = euclid_algorithm(x, p) if gcd != 1: return -1 return k % p p = 10 ** 9 + 7 n, m = [int(x) for x in input().split()] S = pow(m, n, p) k = opposite_element(m, p) l = (2*m - 1) * k % p q = opposite_element(l - 1, p) S += pow(m, n, p) * (pow(l, n, p) - 1) * q S %= p print(S) ```
instruction
0
102,530
12
205,060
No
output
1
102,530
12
205,061
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. For a sequence a of n integers between 1 and m, inclusive, denote f(a) as the number of distinct subsequences of a (including the empty subsequence). You are given two positive integers n and m. Let S be the set of all sequences of length n consisting of numbers from 1 to m. Compute the sum f(a) over all a in S modulo 109 + 7. Input The only line contains two integers n and m (1 ≀ n, m ≀ 106) β€” the number of elements in arrays and the upper bound for elements. Output Print the only integer c β€” the desired sum modulo 109 + 7. Examples Input 1 3 Output 6 Input 2 2 Output 14 Input 3 3 Output 174 Submitted Solution: ``` L = input().split() n = int(L[0]) m = int(L[1]) mod = 1000000007 powr, current = 1, 1 for i in range (0, n): current = (2 * m * current - (current - powr)%mod) powr *= m print(current) ```
instruction
0
102,531
12
205,062
No
output
1
102,531
12
205,063
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. For a sequence a of n integers between 1 and m, inclusive, denote f(a) as the number of distinct subsequences of a (including the empty subsequence). You are given two positive integers n and m. Let S be the set of all sequences of length n consisting of numbers from 1 to m. Compute the sum f(a) over all a in S modulo 109 + 7. Input The only line contains two integers n and m (1 ≀ n, m ≀ 106) β€” the number of elements in arrays and the upper bound for elements. Output Print the only integer c β€” the desired sum modulo 109 + 7. Examples Input 1 3 Output 6 Input 2 2 Output 14 Input 3 3 Output 174 Submitted Solution: ``` import math def euclid_algorithm(a, b): t1, t2 = abs(a), abs(b) #saving equalities: #t1 == x1 * a + y1 * b, #t2 == x2 * a + y2 * b. x1, y1, x2, y2 = int(math.copysign(1, a)), 0, 0, int(math.copysign(1, b)) if t1 < t2: t1, t2 = t2, t1 x1, y1, x2, y2 = x2, y2, x1, y1 while t2 > 0: k = int(t1 // t2) t1, t2 = t2, t1 % t2 #t1 - k * t2 == (x1 - k * x2) * a + (y1 - k * y2) * b x1, y1, x2, y2 = x2, y2, x1 - k * x2, y1 - k * y2 return t1, x1, y1 def opposite_element(x, p): gcd, k, l = euclid_algorithm(x, p) if gcd != 1: return -1 return k % p p = 10 ** 9 + 7 n, m = [int(x) for x in input().split()] S = pow(m, n, p) k = opposite_element(m, p) l = (2*m - 1) * k % p q = opposite_element(l - 1, p) if q != -1: S += pow(m, n, p) * (pow(l, n, p) - 1) * q S %= p else: S += pow(m, n, p) * k S %= p print(S) ```
instruction
0
102,532
12
205,064
No
output
1
102,532
12
205,065
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. For a sequence a of n integers between 1 and m, inclusive, denote f(a) as the number of distinct subsequences of a (including the empty subsequence). You are given two positive integers n and m. Let S be the set of all sequences of length n consisting of numbers from 1 to m. Compute the sum f(a) over all a in S modulo 109 + 7. Input The only line contains two integers n and m (1 ≀ n, m ≀ 106) β€” the number of elements in arrays and the upper bound for elements. Output Print the only integer c β€” the desired sum modulo 109 + 7. Examples Input 1 3 Output 6 Input 2 2 Output 14 Input 3 3 Output 174 Submitted Solution: ``` import math def euclid_algorithm(a, b): t1, t2 = abs(a), abs(b) #saving equalities: #t1 == x1 * a + y1 * b, #t2 == x2 * a + y2 * b. x1, y1, x2, y2 = int(math.copysign(1, a)), 0, 0, int(math.copysign(1, b)) if t1 < t2: t1, t2 = t2, t1 x1, y1, x2, y2 = x2, y2, x1, y1 while t2 > 0: k = int(t1 // t2) t1, t2 = t2, t1 % t2 #t1 - k * t2 == (x1 - k * x2) * a + (y1 - k * y2) * b x1, y1, x2, y2 = x2, y2, x1 - k * x2, y1 - k * y2 return t1, x1, y1 def opposite_element(x, p): gcd, k, l = euclid_algorithm(x, p) if gcd != 1: return -1 return k % p p = 10 ** 9 + 7 n, m = [int(x) for x in input().split()] S = pow(m, n, p) k = opposite_element(m, p) l = (2*m - 1) * k % p q = opposite_element(l - 1, p) if q != -1: S += pow(m, n, p) * (pow(l, n, p) - 1) * q S %= p else: k1 = opposite_element(m, p) S += pow(m-1, n, p) * k1 S %= p print(S) ```
instruction
0
102,533
12
205,066
No
output
1
102,533
12
205,067
Provide tags and a correct Python 3 solution for this coding contest problem. Mike has always been thinking about the harshness of social inequality. He's so obsessed with it that sometimes it even affects him while solving problems. At the moment, Mike has two sequences of positive integers A = [a1, a2, ..., an] and B = [b1, b2, ..., bn] of length n each which he uses to ask people some quite peculiar questions. To test you on how good are you at spotting inequality in life, he wants you to find an "unfair" subset of the original sequence. To be more precise, he wants you to select k numbers P = [p1, p2, ..., pk] such that 1 ≀ pi ≀ n for 1 ≀ i ≀ k and elements in P are distinct. Sequence P will represent indices of elements that you'll select from both sequences. He calls such a subset P "unfair" if and only if the following conditions are satisfied: 2Β·(ap1 + ... + apk) is greater than the sum of all elements from sequence A, and 2Β·(bp1 + ... + bpk) is greater than the sum of all elements from the sequence B. Also, k should be smaller or equal to <image> because it will be to easy to find sequence P if he allowed you to select too many elements! Mike guarantees you that a solution will always exist given the conditions described above, so please help him satisfy his curiosity! Input The first line contains integer n (1 ≀ n ≀ 105) β€” the number of elements in the sequences. On the second line there are n space-separated integers a1, ..., an (1 ≀ ai ≀ 109) β€” elements of sequence A. On the third line there are also n space-separated integers b1, ..., bn (1 ≀ bi ≀ 109) β€” elements of sequence B. Output On the first line output an integer k which represents the size of the found subset. k should be less or equal to <image>. On the next line print k integers p1, p2, ..., pk (1 ≀ pi ≀ n) β€” the elements of sequence P. You can print the numbers in any order you want. Elements in sequence P should be distinct. Example Input 5 8 7 4 8 3 4 2 5 3 7 Output 3 1 4 5
instruction
0
102,566
12
205,132
Tags: constructive algorithms, sortings Correct Solution: ``` n = int(input()) r = list(zip(map(int, input().split()), map(int, input().split()), [x for x in range(1, n + 1)])) r.sort() print("{}\n{}".format(n // 2 + 1, r[n - 1][2]), end=" ") for i in range(n - 2, 0, -2): print(r[i][1] < r[i - 1][1] and r[i - 1][2] or r[i][2], end=" ") if (n & 1) == 0: print(r[0][2]) ```
output
1
102,566
12
205,133
Provide tags and a correct Python 3 solution for this coding contest problem. Mike has always been thinking about the harshness of social inequality. He's so obsessed with it that sometimes it even affects him while solving problems. At the moment, Mike has two sequences of positive integers A = [a1, a2, ..., an] and B = [b1, b2, ..., bn] of length n each which he uses to ask people some quite peculiar questions. To test you on how good are you at spotting inequality in life, he wants you to find an "unfair" subset of the original sequence. To be more precise, he wants you to select k numbers P = [p1, p2, ..., pk] such that 1 ≀ pi ≀ n for 1 ≀ i ≀ k and elements in P are distinct. Sequence P will represent indices of elements that you'll select from both sequences. He calls such a subset P "unfair" if and only if the following conditions are satisfied: 2Β·(ap1 + ... + apk) is greater than the sum of all elements from sequence A, and 2Β·(bp1 + ... + bpk) is greater than the sum of all elements from the sequence B. Also, k should be smaller or equal to <image> because it will be to easy to find sequence P if he allowed you to select too many elements! Mike guarantees you that a solution will always exist given the conditions described above, so please help him satisfy his curiosity! Input The first line contains integer n (1 ≀ n ≀ 105) β€” the number of elements in the sequences. On the second line there are n space-separated integers a1, ..., an (1 ≀ ai ≀ 109) β€” elements of sequence A. On the third line there are also n space-separated integers b1, ..., bn (1 ≀ bi ≀ 109) β€” elements of sequence B. Output On the first line output an integer k which represents the size of the found subset. k should be less or equal to <image>. On the next line print k integers p1, p2, ..., pk (1 ≀ pi ≀ n) β€” the elements of sequence P. You can print the numbers in any order you want. Elements in sequence P should be distinct. Example Input 5 8 7 4 8 3 4 2 5 3 7 Output 3 1 4 5
instruction
0
102,567
12
205,134
Tags: constructive algorithms, sortings Correct Solution: ``` n = int(input()) a= map(int, input().split()) b= map(int, input().split()) indice = sorted(zip(a, b, range(1, n + 1)),reverse=True) rel=[] rel.append(indice[0][2]) for i in range(1, n, 2): tmp = indice[i][2] if i < n-1 and indice[i+1][1] > indice[i][1]: tmp = indice[i+1][2] rel.append(tmp) print(str(len(rel))+"\n") print(*rel) ```
output
1
102,567
12
205,135
Provide tags and a correct Python 3 solution for this coding contest problem. Mike has always been thinking about the harshness of social inequality. He's so obsessed with it that sometimes it even affects him while solving problems. At the moment, Mike has two sequences of positive integers A = [a1, a2, ..., an] and B = [b1, b2, ..., bn] of length n each which he uses to ask people some quite peculiar questions. To test you on how good are you at spotting inequality in life, he wants you to find an "unfair" subset of the original sequence. To be more precise, he wants you to select k numbers P = [p1, p2, ..., pk] such that 1 ≀ pi ≀ n for 1 ≀ i ≀ k and elements in P are distinct. Sequence P will represent indices of elements that you'll select from both sequences. He calls such a subset P "unfair" if and only if the following conditions are satisfied: 2Β·(ap1 + ... + apk) is greater than the sum of all elements from sequence A, and 2Β·(bp1 + ... + bpk) is greater than the sum of all elements from the sequence B. Also, k should be smaller or equal to <image> because it will be to easy to find sequence P if he allowed you to select too many elements! Mike guarantees you that a solution will always exist given the conditions described above, so please help him satisfy his curiosity! Input The first line contains integer n (1 ≀ n ≀ 105) β€” the number of elements in the sequences. On the second line there are n space-separated integers a1, ..., an (1 ≀ ai ≀ 109) β€” elements of sequence A. On the third line there are also n space-separated integers b1, ..., bn (1 ≀ bi ≀ 109) β€” elements of sequence B. Output On the first line output an integer k which represents the size of the found subset. k should be less or equal to <image>. On the next line print k integers p1, p2, ..., pk (1 ≀ pi ≀ n) β€” the elements of sequence P. You can print the numbers in any order you want. Elements in sequence P should be distinct. Example Input 5 8 7 4 8 3 4 2 5 3 7 Output 3 1 4 5
instruction
0
102,568
12
205,136
Tags: constructive algorithms, sortings Correct Solution: ``` n = int(input()) a = [int(x) for x in input().split()] b = [int(x) for x in input().split()] c = list(range(n)) c = sorted(c, key=lambda x: -a[x]) print(n//2 + 1) i = 0 while i < (n + 1) % 2 + 1: print(c[i] + 1, end=' ') i += 1 while i < n: if b[c[i]] > b[c[i + 1]]: print(c[i] + 1, end=' ') else: print(c[i + 1] + 1, end=' ') i += 2 ```
output
1
102,568
12
205,137
Provide tags and a correct Python 3 solution for this coding contest problem. Mike has always been thinking about the harshness of social inequality. He's so obsessed with it that sometimes it even affects him while solving problems. At the moment, Mike has two sequences of positive integers A = [a1, a2, ..., an] and B = [b1, b2, ..., bn] of length n each which he uses to ask people some quite peculiar questions. To test you on how good are you at spotting inequality in life, he wants you to find an "unfair" subset of the original sequence. To be more precise, he wants you to select k numbers P = [p1, p2, ..., pk] such that 1 ≀ pi ≀ n for 1 ≀ i ≀ k and elements in P are distinct. Sequence P will represent indices of elements that you'll select from both sequences. He calls such a subset P "unfair" if and only if the following conditions are satisfied: 2Β·(ap1 + ... + apk) is greater than the sum of all elements from sequence A, and 2Β·(bp1 + ... + bpk) is greater than the sum of all elements from the sequence B. Also, k should be smaller or equal to <image> because it will be to easy to find sequence P if he allowed you to select too many elements! Mike guarantees you that a solution will always exist given the conditions described above, so please help him satisfy his curiosity! Input The first line contains integer n (1 ≀ n ≀ 105) β€” the number of elements in the sequences. On the second line there are n space-separated integers a1, ..., an (1 ≀ ai ≀ 109) β€” elements of sequence A. On the third line there are also n space-separated integers b1, ..., bn (1 ≀ bi ≀ 109) β€” elements of sequence B. Output On the first line output an integer k which represents the size of the found subset. k should be less or equal to <image>. On the next line print k integers p1, p2, ..., pk (1 ≀ pi ≀ n) β€” the elements of sequence P. You can print the numbers in any order you want. Elements in sequence P should be distinct. Example Input 5 8 7 4 8 3 4 2 5 3 7 Output 3 1 4 5
instruction
0
102,569
12
205,138
Tags: constructive algorithms, sortings Correct Solution: ``` n = int(input()) A = [int(x) for x in input().split()] B = [int(x) for x in input().split()] idAB = zip(range(n), A, B) idAB = sorted(idAB, key=lambda x: x[1], reverse=True) ans = [idAB[0][0] + 1] i = 1 while i < n: try: choice = max(idAB[i], idAB[i + 1], key=lambda x: x[2]) ans.append(choice[0] + 1) i += 2 except IndexError: ans.append(idAB[-1][0] + 1) i += 1 ans = sorted(ans) print(len(ans)) print(*ans) ```
output
1
102,569
12
205,139
Provide tags and a correct Python 3 solution for this coding contest problem. Mike has always been thinking about the harshness of social inequality. He's so obsessed with it that sometimes it even affects him while solving problems. At the moment, Mike has two sequences of positive integers A = [a1, a2, ..., an] and B = [b1, b2, ..., bn] of length n each which he uses to ask people some quite peculiar questions. To test you on how good are you at spotting inequality in life, he wants you to find an "unfair" subset of the original sequence. To be more precise, he wants you to select k numbers P = [p1, p2, ..., pk] such that 1 ≀ pi ≀ n for 1 ≀ i ≀ k and elements in P are distinct. Sequence P will represent indices of elements that you'll select from both sequences. He calls such a subset P "unfair" if and only if the following conditions are satisfied: 2Β·(ap1 + ... + apk) is greater than the sum of all elements from sequence A, and 2Β·(bp1 + ... + bpk) is greater than the sum of all elements from the sequence B. Also, k should be smaller or equal to <image> because it will be to easy to find sequence P if he allowed you to select too many elements! Mike guarantees you that a solution will always exist given the conditions described above, so please help him satisfy his curiosity! Input The first line contains integer n (1 ≀ n ≀ 105) β€” the number of elements in the sequences. On the second line there are n space-separated integers a1, ..., an (1 ≀ ai ≀ 109) β€” elements of sequence A. On the third line there are also n space-separated integers b1, ..., bn (1 ≀ bi ≀ 109) β€” elements of sequence B. Output On the first line output an integer k which represents the size of the found subset. k should be less or equal to <image>. On the next line print k integers p1, p2, ..., pk (1 ≀ pi ≀ n) β€” the elements of sequence P. You can print the numbers in any order you want. Elements in sequence P should be distinct. Example Input 5 8 7 4 8 3 4 2 5 3 7 Output 3 1 4 5
instruction
0
102,570
12
205,140
Tags: constructive algorithms, sortings Correct Solution: ``` n=int(input()) a=[[] for i in range(1,n+2)] b=[[]for i in range(1,n+2)] cnt=0 for i in input().split(): cnt+=1 a[cnt]=[-int(i),cnt] cnt=0 for i in input().split(): cnt+=1 b[cnt]=[-int(i),cnt] node=[] use=[0 for i in range(1,n+3)] if n%2==0: a.sort() for i in range(1,n+1,2): if -b[a[i][1]][0]>-b[a[i+1][1]][0]: node.append(a[i][1]) use[a[i][1]]=1 else: node.append(a[i+1][1]) use[a[i+1][1]]=1 for i in range(1,n+1): if use[a[i][1]]==0: node.append(a[i][1]) break if n%2==1: a.sort() use[a[1][1]]=1 node.append(a[1][1]) for i in range(2,n+1,2): if -b[a[i][1]][0]>-b[a[i+1][1]][0]: node.append(a[i][1]) use[a[i][1]]=1 else: node.append(a[i+1][1]) use[a[i+1][1]]=1 print(len(node)) for i in range(len(node)): print(int(node[i]),end=" ") ```
output
1
102,570
12
205,141
Provide tags and a correct Python 3 solution for this coding contest problem. Mike has always been thinking about the harshness of social inequality. He's so obsessed with it that sometimes it even affects him while solving problems. At the moment, Mike has two sequences of positive integers A = [a1, a2, ..., an] and B = [b1, b2, ..., bn] of length n each which he uses to ask people some quite peculiar questions. To test you on how good are you at spotting inequality in life, he wants you to find an "unfair" subset of the original sequence. To be more precise, he wants you to select k numbers P = [p1, p2, ..., pk] such that 1 ≀ pi ≀ n for 1 ≀ i ≀ k and elements in P are distinct. Sequence P will represent indices of elements that you'll select from both sequences. He calls such a subset P "unfair" if and only if the following conditions are satisfied: 2Β·(ap1 + ... + apk) is greater than the sum of all elements from sequence A, and 2Β·(bp1 + ... + bpk) is greater than the sum of all elements from the sequence B. Also, k should be smaller or equal to <image> because it will be to easy to find sequence P if he allowed you to select too many elements! Mike guarantees you that a solution will always exist given the conditions described above, so please help him satisfy his curiosity! Input The first line contains integer n (1 ≀ n ≀ 105) β€” the number of elements in the sequences. On the second line there are n space-separated integers a1, ..., an (1 ≀ ai ≀ 109) β€” elements of sequence A. On the third line there are also n space-separated integers b1, ..., bn (1 ≀ bi ≀ 109) β€” elements of sequence B. Output On the first line output an integer k which represents the size of the found subset. k should be less or equal to <image>. On the next line print k integers p1, p2, ..., pk (1 ≀ pi ≀ n) β€” the elements of sequence P. You can print the numbers in any order you want. Elements in sequence P should be distinct. Example Input 5 8 7 4 8 3 4 2 5 3 7 Output 3 1 4 5
instruction
0
102,571
12
205,142
Tags: constructive algorithms, sortings Correct Solution: ``` n=int(input()); a=list(map(int,input().split())); b=list(map(int,input().split())); p=sorted(zip(range(1,n+1),a,b),key=lambda x:-x[1]); ans=[p[0][0]]; for i in range(1,n,2): ans.append(max(p[i:i+2],key=lambda x:x[2])[0]); ans=sorted(ans); print(len(ans)); print(*ans); ```
output
1
102,571
12
205,143
Provide tags and a correct Python 3 solution for this coding contest problem. Mike has always been thinking about the harshness of social inequality. He's so obsessed with it that sometimes it even affects him while solving problems. At the moment, Mike has two sequences of positive integers A = [a1, a2, ..., an] and B = [b1, b2, ..., bn] of length n each which he uses to ask people some quite peculiar questions. To test you on how good are you at spotting inequality in life, he wants you to find an "unfair" subset of the original sequence. To be more precise, he wants you to select k numbers P = [p1, p2, ..., pk] such that 1 ≀ pi ≀ n for 1 ≀ i ≀ k and elements in P are distinct. Sequence P will represent indices of elements that you'll select from both sequences. He calls such a subset P "unfair" if and only if the following conditions are satisfied: 2Β·(ap1 + ... + apk) is greater than the sum of all elements from sequence A, and 2Β·(bp1 + ... + bpk) is greater than the sum of all elements from the sequence B. Also, k should be smaller or equal to <image> because it will be to easy to find sequence P if he allowed you to select too many elements! Mike guarantees you that a solution will always exist given the conditions described above, so please help him satisfy his curiosity! Input The first line contains integer n (1 ≀ n ≀ 105) β€” the number of elements in the sequences. On the second line there are n space-separated integers a1, ..., an (1 ≀ ai ≀ 109) β€” elements of sequence A. On the third line there are also n space-separated integers b1, ..., bn (1 ≀ bi ≀ 109) β€” elements of sequence B. Output On the first line output an integer k which represents the size of the found subset. k should be less or equal to <image>. On the next line print k integers p1, p2, ..., pk (1 ≀ pi ≀ n) β€” the elements of sequence P. You can print the numbers in any order you want. Elements in sequence P should be distinct. Example Input 5 8 7 4 8 3 4 2 5 3 7 Output 3 1 4 5
instruction
0
102,572
12
205,144
Tags: constructive algorithms, sortings Correct Solution: ``` n = int(input()) A = [int(x) for x in input().split()] B = [int(x) for x in input().split()] idAB = zip(range(n), A, B) idAB = sorted(idAB, key=lambda x: x[1], reverse=True) ans = [idAB[0][0] + 1] i = 1 while i < n: choice = max(idAB[i:i + 2], key=lambda x: x[2]) ans.append(choice[0] + 1) i += 2 ans = sorted(ans) print(len(ans)) print(*ans) ```
output
1
102,572
12
205,145
Provide tags and a correct Python 3 solution for this coding contest problem. Mike has always been thinking about the harshness of social inequality. He's so obsessed with it that sometimes it even affects him while solving problems. At the moment, Mike has two sequences of positive integers A = [a1, a2, ..., an] and B = [b1, b2, ..., bn] of length n each which he uses to ask people some quite peculiar questions. To test you on how good are you at spotting inequality in life, he wants you to find an "unfair" subset of the original sequence. To be more precise, he wants you to select k numbers P = [p1, p2, ..., pk] such that 1 ≀ pi ≀ n for 1 ≀ i ≀ k and elements in P are distinct. Sequence P will represent indices of elements that you'll select from both sequences. He calls such a subset P "unfair" if and only if the following conditions are satisfied: 2Β·(ap1 + ... + apk) is greater than the sum of all elements from sequence A, and 2Β·(bp1 + ... + bpk) is greater than the sum of all elements from the sequence B. Also, k should be smaller or equal to <image> because it will be to easy to find sequence P if he allowed you to select too many elements! Mike guarantees you that a solution will always exist given the conditions described above, so please help him satisfy his curiosity! Input The first line contains integer n (1 ≀ n ≀ 105) β€” the number of elements in the sequences. On the second line there are n space-separated integers a1, ..., an (1 ≀ ai ≀ 109) β€” elements of sequence A. On the third line there are also n space-separated integers b1, ..., bn (1 ≀ bi ≀ 109) β€” elements of sequence B. Output On the first line output an integer k which represents the size of the found subset. k should be less or equal to <image>. On the next line print k integers p1, p2, ..., pk (1 ≀ pi ≀ n) β€” the elements of sequence P. You can print the numbers in any order you want. Elements in sequence P should be distinct. Example Input 5 8 7 4 8 3 4 2 5 3 7 Output 3 1 4 5
instruction
0
102,573
12
205,146
Tags: constructive algorithms, sortings Correct Solution: ``` from functools import cmp_to_key N = int( input() ) A = list( map( int, input().split() ) ) B = list( map( int, input().split() ) ) ord = sorted( list( i for i in range( N ) ), key = cmp_to_key( lambda x, y: A[ y ] - A[ x ] ) ) ans = [ ord[ 0 ] ] for i in range( 1, N, 2 ): if i + 1 == N: ans.append( ord[ i ] ) else: if B[ ord[ i ] ] >= B[ ord[ i + 1 ] ]: ans.append( ord[ i ] ) else: ans.append( ord[ i + 1 ] ) print( len( ans ) ) print( *list( map( lambda x: x + 1, ans ) ) ) ```
output
1
102,573
12
205,147
Provide tags and a correct Python 3 solution for this coding contest problem. You are given an array a of length n that consists of zeros and ones. You can perform the following operation multiple times. The operation consists of two steps: 1. Choose three integers 1 ≀ x < y < z ≀ n, that form an arithmetic progression (y - x = z - y). 2. Flip the values a_x, a_y, a_z (i.e. change 1 to 0, change 0 to 1). Determine if it is possible to make all elements of the array equal to zero. If yes, print the operations that lead the the all-zero state. Your solution should not contain more than (⌊ n/3 βŒ‹ + 12) operations. Here ⌊ q βŒ‹ denotes the number q rounded down. We can show that it is possible to make all elements equal to zero in no more than this number of operations whenever it is possible to do so at all. Input The first line contains a single integer n (3 ≀ n ≀ 10^5) β€” the length of the array. The second line contains n integers a_1, a_2, …, a_n (0 ≀ a_i ≀ 1) β€” the elements of the array. Output Print "YES" (without quotes) if the answer exists, otherwise print "NO" (without quotes). You can print each letter in any case (upper or lower). If there is an answer, in the second line print an integer m (0 ≀ m ≀ (⌊ n/3 βŒ‹ + 12)) β€” the number of operations in your answer. After that in (i + 2)-th line print the i-th operations β€” the integers x_i, y_i, z_i. You can print them in arbitrary order. Examples Input 5 1 1 0 1 1 Output YES 2 1 3 5 2 3 4 Input 3 0 1 0 Output NO Note In the first sample the shown output corresponds to the following solution: * 1 1 0 1 1 (initial state); * 0 1 1 1 0 (the flipped positions are the first, the third and the fifth elements); * 0 0 0 0 0 (the flipped positions are the second, the third and the fourth elements). Other answers are also possible. In this test the number of operations should not exceed ⌊ 5/3 βŒ‹ + 12 = 1 + 12 = 13. In the second sample the only available operation is to flip all the elements. This way it is only possible to obtain the arrays 0 1 0 and 1 0 1, but it is impossible to make all elements equal to zero.
instruction
0
102,901
12
205,802
Tags: constructive algorithms Correct Solution: ``` l = [((1 << i) | (1 << (i + j)) | (1 << (i + j * 2)), i, j) for i in range(6) for j in range(1, 6) if i + j * 2 < 11] six = [None] * (1 << 6) for i in range(len(l)): for j in range(i + 1, len(l)): six[(l[i][0] ^ l[j][0]) & 0b111111] = (l[i][1:], l[j][1:]) n = int(input()) s = input().split() cur = 0 ans = [] while len(s) - cur > 11: part = int(''.join(s[cur:cur + 6])[::-1], 2) if not part: cur += 6 continue (i, j), (u, v) = six[part] ans.append((cur + i, cur + i + j, cur + i + j * 2)) ans.append((cur + u, cur + u + v, cur + u + v * 2)) for i in ans[-2:]: for j in i: try: s[j] = {'0': '1', '1': '0'}[s[j]] except: print(s[j]) exit() cur += 6 cur = max(0, min(cur, len(s) - 8)) l = [((1 << i) | (1 << (i + j)) | (1 << (i + j * 2)), i, j) for i in range(len(s) - cur) for j in (1, 3) if i + j * 2 < len(s) - cur] lt = {1 << i: i for i in range(len(l))} bit = [[] for _ in range(1 << len(l))] for i in range(1, 1 << len(l)): bit[i] = bit[i - (i & -i)][:] bit[i].append(l[lt[i & -i]]) eight = {} for b in bit: res, a = 0, [] for i in b: res ^= i[0] a.append(i[1:]) if res in eight and len(eight[res]) <= len(a): continue eight[res] = a part = int(''.join(s[cur:])[::-1], 2) if part not in eight: print('NO') exit() for u, v in eight[part]: ans.append((cur + u, cur + u + v, cur + u + v * 2)) for j in ans[-1]: s[j] = {'0': '1', '1': '0'}[s[j]] print('YES') print(len(ans)) for i in ans: print(*map(lambda x: x + 1, i)) ```
output
1
102,901
12
205,803
Provide tags and a correct Python 3 solution for this coding contest problem. You are given an array a of length n that consists of zeros and ones. You can perform the following operation multiple times. The operation consists of two steps: 1. Choose three integers 1 ≀ x < y < z ≀ n, that form an arithmetic progression (y - x = z - y). 2. Flip the values a_x, a_y, a_z (i.e. change 1 to 0, change 0 to 1). Determine if it is possible to make all elements of the array equal to zero. If yes, print the operations that lead the the all-zero state. Your solution should not contain more than (⌊ n/3 βŒ‹ + 12) operations. Here ⌊ q βŒ‹ denotes the number q rounded down. We can show that it is possible to make all elements equal to zero in no more than this number of operations whenever it is possible to do so at all. Input The first line contains a single integer n (3 ≀ n ≀ 10^5) β€” the length of the array. The second line contains n integers a_1, a_2, …, a_n (0 ≀ a_i ≀ 1) β€” the elements of the array. Output Print "YES" (without quotes) if the answer exists, otherwise print "NO" (without quotes). You can print each letter in any case (upper or lower). If there is an answer, in the second line print an integer m (0 ≀ m ≀ (⌊ n/3 βŒ‹ + 12)) β€” the number of operations in your answer. After that in (i + 2)-th line print the i-th operations β€” the integers x_i, y_i, z_i. You can print them in arbitrary order. Examples Input 5 1 1 0 1 1 Output YES 2 1 3 5 2 3 4 Input 3 0 1 0 Output NO Note In the first sample the shown output corresponds to the following solution: * 1 1 0 1 1 (initial state); * 0 1 1 1 0 (the flipped positions are the first, the third and the fifth elements); * 0 0 0 0 0 (the flipped positions are the second, the third and the fourth elements). Other answers are also possible. In this test the number of operations should not exceed ⌊ 5/3 βŒ‹ + 12 = 1 + 12 = 13. In the second sample the only available operation is to flip all the elements. This way it is only possible to obtain the arrays 0 1 0 and 1 0 1, but it is impossible to make all elements equal to zero.
instruction
0
102,902
12
205,804
Tags: constructive algorithms Correct Solution: ``` def solve(a): l = len(a) d = sum(a[i] * 2 ** i for i in range(l)) if d == 0: return [] usable = [] if l >= 3: for i in range(l - 2): usable.append(0b111 << i) if l >= 5: for i in range(l - 4): usable.append(0b10101 << i) if l >= 7: for i in range(l - 6): usable.append(0b1001001 << i) ul = len(usable) best_answer = None for mask in range(1 << ul): start = 0 clone = mask cnt = 0 while clone: if clone % 2 == 1: start ^= usable[cnt] clone //= 2 cnt += 1 if start == d: answer = [] clone = mask cnt = 0 while clone: if clone % 2 == 1: answer.append([]) used = usable[cnt] cnt2 = 1 while used: if used % 2 == 1: answer[-1].append(cnt2) cnt2 += 1 used //= 2 clone //= 2 cnt += 1 if best_answer is None or len(best_answer) > len(answer): best_answer = answer return best_answer if __name__ == '__main__': n = int(input()) a = list(map(int, input().split())) if len(a) <= 10: sol = solve(a) if sol is None: print("NO") exit(0) print("YES") print(len(sol)) for t in sol: print(' '.join(map(str, t))) exit(0) operations = [] while len(a) > 10: l = len(a) last = a[-3:] if last == [1, 1, 1]: operations.append([l - 2, l - 1, l]) elif last == [1, 1, 0]: operations.append([l - 3, l - 2, l - 1]) a[-4] ^= 1 elif last == [1, 0, 1]: operations.append([l - 4, l - 2, l]) a[-5] ^= 1 elif last == [0, 1, 1]: nxt = a[-6:-3] if nxt == [1, 1, 1]: operations.append([l - 8, l - 4, l]) operations.append([l - 5, l - 3, l - 1]) a[-9] ^= 1 elif nxt == [1, 1, 0]: operations.append([l - 8, l - 4, l]) operations.append([l - 9, l - 5, l - 1]) a[-9] ^= 1 a[-10] ^= 1 elif nxt == [1, 0, 1]: operations.append([l - 6, l - 3, l]) operations.append([l - 9, l - 5, l - 1]) a[-7] ^= 1 a[-10] ^= 1 elif nxt == [0, 1, 1]: operations.append([l - 6, l - 3, l]) operations.append([l - 7, l - 4, l - 1]) a[-7] ^= 1 a[-8] ^= 1 elif nxt == [1, 0, 0]: operations.append([l - 2, l - 1, l]) operations.append([l - 8, l - 5, l - 2]) a[-9] ^= 1 elif nxt == [0, 1, 0]: operations.append([l - 2, l - 1, l]) operations.append([l - 6, l - 4, l - 2]) a[-7] ^= 1 elif nxt == [0, 0, 1]: operations.append([l - 10, l - 5, l]) operations.append([l - 5, l - 3, l - 1]) a[-11] ^= 1 elif nxt == [0, 0, 0]: operations.append([l - 8, l - 4, l]) operations.append([l - 7, l - 4, l - 1]) a[-9] ^= 1 a[-8] ^= 1 a.pop() a.pop() a.pop() elif last == [1, 0, 0]: operations.append([l - 4, l - 3, l - 2]) a[-5] ^= 1 a[-4] ^= 1 elif last == [0, 1, 0]: operations.append([l - 5, l - 3, l - 1]) a[-6] ^= 1 a[-4] ^= 1 elif last == [0, 0, 1]: operations.append([l - 6, l - 3, l]) a[-7] ^= 1 a[-4] ^= 1 a.pop() a.pop() a.pop() while len(a) < 8: a.append(0) sol = solve(a) print("YES") sol = operations + sol print(len(sol)) for t in sol: print(' '.join(map(str, t))) ```
output
1
102,902
12
205,805
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. You are given an array a of length n that consists of zeros and ones. You can perform the following operation multiple times. The operation consists of two steps: 1. Choose three integers 1 ≀ x < y < z ≀ n, that form an arithmetic progression (y - x = z - y). 2. Flip the values a_x, a_y, a_z (i.e. change 1 to 0, change 0 to 1). Determine if it is possible to make all elements of the array equal to zero. If yes, print the operations that lead the the all-zero state. Your solution should not contain more than (⌊ n/3 βŒ‹ + 12) operations. Here ⌊ q βŒ‹ denotes the number q rounded down. We can show that it is possible to make all elements equal to zero in no more than this number of operations whenever it is possible to do so at all. Input The first line contains a single integer n (3 ≀ n ≀ 10^5) β€” the length of the array. The second line contains n integers a_1, a_2, …, a_n (0 ≀ a_i ≀ 1) β€” the elements of the array. Output Print "YES" (without quotes) if the answer exists, otherwise print "NO" (without quotes). You can print each letter in any case (upper or lower). If there is an answer, in the second line print an integer m (0 ≀ m ≀ (⌊ n/3 βŒ‹ + 12)) β€” the number of operations in your answer. After that in (i + 2)-th line print the i-th operations β€” the integers x_i, y_i, z_i. You can print them in arbitrary order. Examples Input 5 1 1 0 1 1 Output YES 2 1 3 5 2 3 4 Input 3 0 1 0 Output NO Note In the first sample the shown output corresponds to the following solution: * 1 1 0 1 1 (initial state); * 0 1 1 1 0 (the flipped positions are the first, the third and the fifth elements); * 0 0 0 0 0 (the flipped positions are the second, the third and the fourth elements). Other answers are also possible. In this test the number of operations should not exceed ⌊ 5/3 βŒ‹ + 12 = 1 + 12 = 13. In the second sample the only available operation is to flip all the elements. This way it is only possible to obtain the arrays 0 1 0 and 1 0 1, but it is impossible to make all elements equal to zero. Submitted Solution: ``` n=int(input()) a=input().split() if n>3: print("YES") print(2) print(1,3,5) print(2,3,4) else: print("NO") ```
instruction
0
102,903
12
205,806
No
output
1
102,903
12
205,807
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. You are given an array a of length n that consists of zeros and ones. You can perform the following operation multiple times. The operation consists of two steps: 1. Choose three integers 1 ≀ x < y < z ≀ n, that form an arithmetic progression (y - x = z - y). 2. Flip the values a_x, a_y, a_z (i.e. change 1 to 0, change 0 to 1). Determine if it is possible to make all elements of the array equal to zero. If yes, print the operations that lead the the all-zero state. Your solution should not contain more than (⌊ n/3 βŒ‹ + 12) operations. Here ⌊ q βŒ‹ denotes the number q rounded down. We can show that it is possible to make all elements equal to zero in no more than this number of operations whenever it is possible to do so at all. Input The first line contains a single integer n (3 ≀ n ≀ 10^5) β€” the length of the array. The second line contains n integers a_1, a_2, …, a_n (0 ≀ a_i ≀ 1) β€” the elements of the array. Output Print "YES" (without quotes) if the answer exists, otherwise print "NO" (without quotes). You can print each letter in any case (upper or lower). If there is an answer, in the second line print an integer m (0 ≀ m ≀ (⌊ n/3 βŒ‹ + 12)) β€” the number of operations in your answer. After that in (i + 2)-th line print the i-th operations β€” the integers x_i, y_i, z_i. You can print them in arbitrary order. Examples Input 5 1 1 0 1 1 Output YES 2 1 3 5 2 3 4 Input 3 0 1 0 Output NO Note In the first sample the shown output corresponds to the following solution: * 1 1 0 1 1 (initial state); * 0 1 1 1 0 (the flipped positions are the first, the third and the fifth elements); * 0 0 0 0 0 (the flipped positions are the second, the third and the fourth elements). Other answers are also possible. In this test the number of operations should not exceed ⌊ 5/3 βŒ‹ + 12 = 1 + 12 = 13. In the second sample the only available operation is to flip all the elements. This way it is only possible to obtain the arrays 0 1 0 and 1 0 1, but it is impossible to make all elements equal to zero. Submitted Solution: ``` n = int(input()) k = list(map(int, input().split())) mem=[] count=0 for x in range(1,n): for y in range(x+1,n): for z in range(y+1,n): if y - x == z - y: if k[x] == 1: k[x] = 0 else: k[x] = 1 if k[y] == 1: k[y] = 0 else: k[z] = 1 if k[x] == 1: k[z] = 0 else: k[z] = 1 mem.append([x,y,z]) count+=1 if k.count(0) == n: break if count == 0: print("NO") else: print("YES") print(count) for l in range(0,count): print(mem[l]) ```
instruction
0
102,904
12
205,808
No
output
1
102,904
12
205,809
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. You are given an array a of length n that consists of zeros and ones. You can perform the following operation multiple times. The operation consists of two steps: 1. Choose three integers 1 ≀ x < y < z ≀ n, that form an arithmetic progression (y - x = z - y). 2. Flip the values a_x, a_y, a_z (i.e. change 1 to 0, change 0 to 1). Determine if it is possible to make all elements of the array equal to zero. If yes, print the operations that lead the the all-zero state. Your solution should not contain more than (⌊ n/3 βŒ‹ + 12) operations. Here ⌊ q βŒ‹ denotes the number q rounded down. We can show that it is possible to make all elements equal to zero in no more than this number of operations whenever it is possible to do so at all. Input The first line contains a single integer n (3 ≀ n ≀ 10^5) β€” the length of the array. The second line contains n integers a_1, a_2, …, a_n (0 ≀ a_i ≀ 1) β€” the elements of the array. Output Print "YES" (without quotes) if the answer exists, otherwise print "NO" (without quotes). You can print each letter in any case (upper or lower). If there is an answer, in the second line print an integer m (0 ≀ m ≀ (⌊ n/3 βŒ‹ + 12)) β€” the number of operations in your answer. After that in (i + 2)-th line print the i-th operations β€” the integers x_i, y_i, z_i. You can print them in arbitrary order. Examples Input 5 1 1 0 1 1 Output YES 2 1 3 5 2 3 4 Input 3 0 1 0 Output NO Note In the first sample the shown output corresponds to the following solution: * 1 1 0 1 1 (initial state); * 0 1 1 1 0 (the flipped positions are the first, the third and the fifth elements); * 0 0 0 0 0 (the flipped positions are the second, the third and the fourth elements). Other answers are also possible. In this test the number of operations should not exceed ⌊ 5/3 βŒ‹ + 12 = 1 + 12 = 13. In the second sample the only available operation is to flip all the elements. This way it is only possible to obtain the arrays 0 1 0 and 1 0 1, but it is impossible to make all elements equal to zero. Submitted Solution: ``` def solve(a): l = len(a) d = sum(a[i] * 2 ** i for i in range(l)) if d == 0: return [] usable = [] if l >= 3: for i in range(l - 2): usable.append(0b111 << i) if l >= 5: for i in range(l - 4): usable.append(0b10101 << i) if l >= 7: for i in range(l - 6): usable.append(0b1001001 << i) ul = len(usable) for mask in range(1 << ul): start = 0 clone = mask cnt = 0 while clone: if clone % 2 == 1: start ^= usable[cnt] clone //= 2 cnt += 1 if start == d: answer = [] clone = mask cnt = 0 while clone: if clone % 2 == 1: answer.append([]) used = usable[cnt] cnt2 = 1 while used: if used % 2 == 1: answer[-1].append(cnt2) cnt2 += 1 used //= 2 clone //= 2 cnt += 1 return answer if __name__ == '__main__': n = int(input()) a = list(map(int, input().split())) if len(a) <= 10: sol = solve(a) if sol is None: print("NO") exit(0) print("YES") print(len(sol)) for t in sol: print(' '.join(map(str, t))) exit(0) operations = [] while len(a) > 10: l = len(a) last = a[-3:] if last == [1, 1, 1]: operations.append([l - 2, l - 1, l]) elif last == [1, 1, 0]: operations.append([l - 3, l - 2, l - 1]) a[-4] ^= 1 elif last == [1, 0, 1]: operations.append([l - 4, l - 2, l]) a[-5] ^= 1 elif last == [0, 1, 1]: nxt = a[-6:-3] if nxt == [1, 1, 1]: operations.append([l - 8, l - 4, l]) operations.append([l - 5, l - 3, l - 1]) a[-9] ^= 1 elif nxt == [1, 1, 0]: operations.append([l - 8, l - 4, l]) operations.append([l - 9, l - 5, l - 1]) a[-9] ^= 1 a[-10] ^= 1 elif nxt == [1, 0, 1]: operations.append([l - 6, l - 3, l]) operations.append([l - 9, l - 5, l - 1]) a[-7] ^= 1 a[-10] ^= 1 elif nxt == [0, 1, 1]: operations.append([l - 6, l - 3, l]) operations.append([l - 7, l - 4, l - 1]) a[-7] ^= 1 a[-8] ^= 1 elif nxt == [1, 0, 0]: operations.append([l - 2, l - 1, l]) operations.append([l - 8, l - 5, l - 2]) a[-9] ^= 1 elif nxt == [0, 1, 0]: operations.append([l - 2, l - 1, l]) operations.append([l - 6, l - 4, l - 2]) a[-7] ^= 1 elif nxt == [0, 0, 1]: operations.append([l - 10, l - 5, l]) operations.append([l - 5, l - 3, l - 1]) a[-11] ^= 1 elif nxt == [0, 0, 0]: operations.append([l - 8, l - 4, l]) operations.append([l - 7, l - 4, l - 1]) a[-9] ^= 1 a[-10] ^= 1 a.pop() a.pop() a.pop() elif last == [1, 0, 0]: operations.append([l - 4, l - 3, l - 2]) a[-5] ^= 1 a[-4] ^= 1 elif last == [0, 1, 0]: operations.append([l - 5, l - 3, l - 1]) a[-6] ^= 1 a[-4] ^= 1 elif last == [0, 0, 1]: operations.append([l - 6, l - 3, l]) a[-7] ^= 1 a[-4] ^= 1 a.pop() a.pop() a.pop() while len(a) < 8: a.append(0) sol = solve(a) print("YES") sol = operations + sol print(len(sol)) for t in sol: print(' '.join(map(str, t))) ```
instruction
0
102,905
12
205,810
No
output
1
102,905
12
205,811
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. You are given an array a of length n that consists of zeros and ones. You can perform the following operation multiple times. The operation consists of two steps: 1. Choose three integers 1 ≀ x < y < z ≀ n, that form an arithmetic progression (y - x = z - y). 2. Flip the values a_x, a_y, a_z (i.e. change 1 to 0, change 0 to 1). Determine if it is possible to make all elements of the array equal to zero. If yes, print the operations that lead the the all-zero state. Your solution should not contain more than (⌊ n/3 βŒ‹ + 12) operations. Here ⌊ q βŒ‹ denotes the number q rounded down. We can show that it is possible to make all elements equal to zero in no more than this number of operations whenever it is possible to do so at all. Input The first line contains a single integer n (3 ≀ n ≀ 10^5) β€” the length of the array. The second line contains n integers a_1, a_2, …, a_n (0 ≀ a_i ≀ 1) β€” the elements of the array. Output Print "YES" (without quotes) if the answer exists, otherwise print "NO" (without quotes). You can print each letter in any case (upper or lower). If there is an answer, in the second line print an integer m (0 ≀ m ≀ (⌊ n/3 βŒ‹ + 12)) β€” the number of operations in your answer. After that in (i + 2)-th line print the i-th operations β€” the integers x_i, y_i, z_i. You can print them in arbitrary order. Examples Input 5 1 1 0 1 1 Output YES 2 1 3 5 2 3 4 Input 3 0 1 0 Output NO Note In the first sample the shown output corresponds to the following solution: * 1 1 0 1 1 (initial state); * 0 1 1 1 0 (the flipped positions are the first, the third and the fifth elements); * 0 0 0 0 0 (the flipped positions are the second, the third and the fourth elements). Other answers are also possible. In this test the number of operations should not exceed ⌊ 5/3 βŒ‹ + 12 = 1 + 12 = 13. In the second sample the only available operation is to flip all the elements. This way it is only possible to obtain the arrays 0 1 0 and 1 0 1, but it is impossible to make all elements equal to zero. Submitted Solution: ``` l = [((1 << i) | (1 << (i + j)) | (1 << (i + j * 2)), i, j) for i in range(6) for j in range(1, 6) if i + j * 2 < 11] six = [None] * (1 << 6) for i in range(len(l)): for j in range(i + 1, len(l)): six[(l[i][0] ^ l[j][0]) & 0b111111] = (l[i][1:], l[j][1:]) n = int(input()) s = input().split() cur = 0 ans = [] while len(s) - cur > 8: part = int(''.join(s[cur:cur + 6])[::-1], 2) (i, j), (u, v) = six[part] ans.append((cur + i, cur + i + j, cur + i + j * 2)) ans.append((cur + u, cur + u + v, cur + u + v * 2)) for i in ans[-2:]: for j in i: s[j] = {'0': '1', '1': '0'}[s[j]] cur += 6 l = [((1 << i) | (1 << (i + j)) | (1 << (i + j * 2)), i, j) for i in range(len(s) - cur) for j in (1, 3) if i + j * 2 < len(s) - cur] lt = {1 << i: i for i in range(len(l))} bit = [[] for _ in range(1 << len(l))] for i in range(1, 1 << len(l)): bit[i] = bit[i - (i & -i)][:] bit[i].append(l[lt[i & -i]]) eight = {} for b in bit: res, a = 0, [] for i in b: res ^= i[0] a.append(i[1:]) if res in eight and len(eight[res]) <= len(a): continue eight[res] = a part = int(''.join(s[cur:])[::-1], 2) if part not in eight: print('NO') exit() for u, v in eight[part]: ans.append((cur + u, cur + u + v, cur + u + v * 2)) for j in ans[-1]: s[j] = {'0': '1', '1': '0'}[s[j]] print('YES') print(len(ans)) for i in ans: print(*map(lambda x: x + 1, i)) ```
instruction
0
102,906
12
205,812
No
output
1
102,906
12
205,813
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. One Saturday afternoon Egor was playing his favorite RPG game. While discovering new lands and territories, he came across the following sign: <image> Egor is a passionate player, but he is an algorithmician as well. That's why he instantly spotted four common letters in two words on the sign above β€” if we permute the letters "R", "E", "G", "O" from the first word, we can obtain the letters "O", "G", "R", "E". Egor got inspired by the sign and right away he came up with a problem about permutations. You are given a permutation of length n. You have to split it into some non-empty subsequences so that each element of the permutation belongs to exactly one subsequence. Each subsequence must be monotonic β€” that is, either increasing or decreasing. Sequence is called to be a subsequence if it can be derived from permutation by deleting some (possibly none) elements without changing the order of the remaining elements. The number of subsequences should be small enough β€” let f(n) be the minimum integer k such that every permutation of length n can be partitioned into at most k monotonic subsequences. You need to split the permutation into at most f(n) monotonic subsequences. Input The first line contains one integer t (1 ≀ t ≀ 10^5) β€” the number of test cases. You can only use t = 1 in hacks. Next, descriptions of t test cases come, each of them in the following format. The first line of a single test case contains one integer n (1 ≀ n ≀ 10^5) β€” the length of the permutation. The second line contains n distinct integers a_i (1 ≀ a_i ≀ n) β€” the permutation itself. The sum of the values of n over all test cases doesn't exceed 10^5. Output For each test case print the answer in the following format: In the first line print k (1 ≀ k ≀ f(n)) β€” the number of the subsequences in the partition. In the next k lines, print the descriptions of found subsequences. Each description should start with a number l_i (1 ≀ l_i ≀ n) β€” the length of the corresponding subsequence, followed by l_i integers β€” the values of this subsequence in the order in which they occur in the permutation. Each subsequence you output must be either increasing or decreasing. In case there are multiple possible answers, print any of them. Example Input 3 4 4 3 1 2 6 4 5 6 1 3 2 10 1 2 3 4 5 6 7 8 9 10 Output 2 3 4 3 1 1 2 3 2 4 1 2 5 6 2 3 2 1 10 1 2 3 4 5 6 7 8 9 10 Note In the example, we can split: * [4, 3, 1, 2] into [4, 3, 1], [2] * [4, 5, 6, 1, 3, 2] into [4, 1], [5, 6] and [3, 2] * [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] into [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] Surely, there are many more answers possible. Submitted Solution: ``` def longest_increasing_subsequence(X): """Returns the Longest Increasing Subsequence in the Given List/Array""" N = len(X) P = [0] * N M = [0] * (N+1) L = 0 for i in range(N): lo = 1 hi = L while lo <= hi: mid = (lo+hi)//2 if (X[M[mid]] < X[i]): lo = mid+1 else: hi = mid-1 newL = lo P[i] = M[newL-1] M[newL] = i if (newL > L): L = newL S = [] k = M[L] for i in range(L-1, -1, -1): S.append(X[k]) k = P[k] return S[::-1] def nos(lis): flag = 0 count = 0 terms = [] while(len(lis) != 0): forw = longest_increasing_subsequence(lis) back = longest_increasing_subsequence(lis[::-1]) if(len(forw) >= len(back)): for i in forw: lis.remove(i) terms.append(forw) count += 1 elif(len(back) > len(forw)): for i in back: lis.remove(i) terms.append(back) count += 1 else: lisf = lis.copy() lisb = lis.copy() for i in forw: lisf.remove(i) for i in back: lisb.remove(i) a, x = nos(lisf) b, y = nos(lisb) if( a <= b): lis = [] terms = terms + x count += a else: lis = [] terms = terms + y count += b return(count, terms) cases = int(input()) for case in range(cases): n = int(input()) perm = [int(x) for x in input().split()] k, terms = nos(perm) print(k) for j in terms: print(len(j), " ".join([str(x) for x in j])) ```
instruction
0
102,920
12
205,840
No
output
1
102,920
12
205,841
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. One Saturday afternoon Egor was playing his favorite RPG game. While discovering new lands and territories, he came across the following sign: <image> Egor is a passionate player, but he is an algorithmician as well. That's why he instantly spotted four common letters in two words on the sign above β€” if we permute the letters "R", "E", "G", "O" from the first word, we can obtain the letters "O", "G", "R", "E". Egor got inspired by the sign and right away he came up with a problem about permutations. You are given a permutation of length n. You have to split it into some non-empty subsequences so that each element of the permutation belongs to exactly one subsequence. Each subsequence must be monotonic β€” that is, either increasing or decreasing. Sequence is called to be a subsequence if it can be derived from permutation by deleting some (possibly none) elements without changing the order of the remaining elements. The number of subsequences should be small enough β€” let f(n) be the minimum integer k such that every permutation of length n can be partitioned into at most k monotonic subsequences. You need to split the permutation into at most f(n) monotonic subsequences. Input The first line contains one integer t (1 ≀ t ≀ 10^5) β€” the number of test cases. You can only use t = 1 in hacks. Next, descriptions of t test cases come, each of them in the following format. The first line of a single test case contains one integer n (1 ≀ n ≀ 10^5) β€” the length of the permutation. The second line contains n distinct integers a_i (1 ≀ a_i ≀ n) β€” the permutation itself. The sum of the values of n over all test cases doesn't exceed 10^5. Output For each test case print the answer in the following format: In the first line print k (1 ≀ k ≀ f(n)) β€” the number of the subsequences in the partition. In the next k lines, print the descriptions of found subsequences. Each description should start with a number l_i (1 ≀ l_i ≀ n) β€” the length of the corresponding subsequence, followed by l_i integers β€” the values of this subsequence in the order in which they occur in the permutation. Each subsequence you output must be either increasing or decreasing. In case there are multiple possible answers, print any of them. Example Input 3 4 4 3 1 2 6 4 5 6 1 3 2 10 1 2 3 4 5 6 7 8 9 10 Output 2 3 4 3 1 1 2 3 2 4 1 2 5 6 2 3 2 1 10 1 2 3 4 5 6 7 8 9 10 Note In the example, we can split: * [4, 3, 1, 2] into [4, 3, 1], [2] * [4, 5, 6, 1, 3, 2] into [4, 1], [5, 6] and [3, 2] * [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] into [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] Surely, there are many more answers possible. Submitted Solution: ``` print("114") ```
instruction
0
102,921
12
205,842
No
output
1
102,921
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205,843
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. One Saturday afternoon Egor was playing his favorite RPG game. While discovering new lands and territories, he came across the following sign: <image> Egor is a passionate player, but he is an algorithmician as well. That's why he instantly spotted four common letters in two words on the sign above β€” if we permute the letters "R", "E", "G", "O" from the first word, we can obtain the letters "O", "G", "R", "E". Egor got inspired by the sign and right away he came up with a problem about permutations. You are given a permutation of length n. You have to split it into some non-empty subsequences so that each element of the permutation belongs to exactly one subsequence. Each subsequence must be monotonic β€” that is, either increasing or decreasing. Sequence is called to be a subsequence if it can be derived from permutation by deleting some (possibly none) elements without changing the order of the remaining elements. The number of subsequences should be small enough β€” let f(n) be the minimum integer k such that every permutation of length n can be partitioned into at most k monotonic subsequences. You need to split the permutation into at most f(n) monotonic subsequences. Input The first line contains one integer t (1 ≀ t ≀ 10^5) β€” the number of test cases. You can only use t = 1 in hacks. Next, descriptions of t test cases come, each of them in the following format. The first line of a single test case contains one integer n (1 ≀ n ≀ 10^5) β€” the length of the permutation. The second line contains n distinct integers a_i (1 ≀ a_i ≀ n) β€” the permutation itself. The sum of the values of n over all test cases doesn't exceed 10^5. Output For each test case print the answer in the following format: In the first line print k (1 ≀ k ≀ f(n)) β€” the number of the subsequences in the partition. In the next k lines, print the descriptions of found subsequences. Each description should start with a number l_i (1 ≀ l_i ≀ n) β€” the length of the corresponding subsequence, followed by l_i integers β€” the values of this subsequence in the order in which they occur in the permutation. Each subsequence you output must be either increasing or decreasing. In case there are multiple possible answers, print any of them. Example Input 3 4 4 3 1 2 6 4 5 6 1 3 2 10 1 2 3 4 5 6 7 8 9 10 Output 2 3 4 3 1 1 2 3 2 4 1 2 5 6 2 3 2 1 10 1 2 3 4 5 6 7 8 9 10 Note In the example, we can split: * [4, 3, 1, 2] into [4, 3, 1], [2] * [4, 5, 6, 1, 3, 2] into [4, 1], [5, 6] and [3, 2] * [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] into [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] Surely, there are many more answers possible. Submitted Solution: ``` def longest_increasing_subsequence(X): """Returns the Longest Increasing Subsequence in the Given List/Array""" N = len(X) P = [0] * N M = [0] * (N+1) L = 0 for i in range(N): lo = 1 hi = L while lo <= hi: mid = (lo+hi)//2 if (X[M[mid]] < X[i]): lo = mid+1 else: hi = mid-1 newL = lo P[i] = M[newL-1] M[newL] = i if (newL > L): L = newL S = [] k = M[L] for i in range(L-1, -1, -1): S.append(X[k]) k = P[k] return S[::-1] def nos(lis): flag = 0 count = 0 terms = [] while(len(lis) != 0): forw = longest_increasing_subsequence(lis) back = longest_increasing_subsequence(lis[::-1]) if(len(forw) >= len(back)): for i in forw: lis.remove(i) terms.append(forw) count += 1 elif(len(back) > len(forw)): for i in back: lis.remove(i) terms.append(back) count += 1 else: lisf = lis.copy() lisb = lis.copy() for i in forw: lisf.remove(i) for i in back: lisb.remove(i) a, x = nos(lisf) b, y = nos(lisb) if( a <= b): lis = [] terms = terms + x count += a else: lis = [] terms = terms + y count += b return(count, terms) cases = int(input()) for case in range(cases): n = int(input()) perm = [int(x) for x in input().split()] k, terms = nos(perm) print(k) for j in terms: print(" ".join([str(x) for x in j])) ```
instruction
0
102,922
12
205,844
No
output
1
102,922
12
205,845
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response. One Saturday afternoon Egor was playing his favorite RPG game. While discovering new lands and territories, he came across the following sign: <image> Egor is a passionate player, but he is an algorithmician as well. That's why he instantly spotted four common letters in two words on the sign above β€” if we permute the letters "R", "E", "G", "O" from the first word, we can obtain the letters "O", "G", "R", "E". Egor got inspired by the sign and right away he came up with a problem about permutations. You are given a permutation of length n. You have to split it into some non-empty subsequences so that each element of the permutation belongs to exactly one subsequence. Each subsequence must be monotonic β€” that is, either increasing or decreasing. Sequence is called to be a subsequence if it can be derived from permutation by deleting some (possibly none) elements without changing the order of the remaining elements. The number of subsequences should be small enough β€” let f(n) be the minimum integer k such that every permutation of length n can be partitioned into at most k monotonic subsequences. You need to split the permutation into at most f(n) monotonic subsequences. Input The first line contains one integer t (1 ≀ t ≀ 10^5) β€” the number of test cases. You can only use t = 1 in hacks. Next, descriptions of t test cases come, each of them in the following format. The first line of a single test case contains one integer n (1 ≀ n ≀ 10^5) β€” the length of the permutation. The second line contains n distinct integers a_i (1 ≀ a_i ≀ n) β€” the permutation itself. The sum of the values of n over all test cases doesn't exceed 10^5. Output For each test case print the answer in the following format: In the first line print k (1 ≀ k ≀ f(n)) β€” the number of the subsequences in the partition. In the next k lines, print the descriptions of found subsequences. Each description should start with a number l_i (1 ≀ l_i ≀ n) β€” the length of the corresponding subsequence, followed by l_i integers β€” the values of this subsequence in the order in which they occur in the permutation. Each subsequence you output must be either increasing or decreasing. In case there are multiple possible answers, print any of them. Example Input 3 4 4 3 1 2 6 4 5 6 1 3 2 10 1 2 3 4 5 6 7 8 9 10 Output 2 3 4 3 1 1 2 3 2 4 1 2 5 6 2 3 2 1 10 1 2 3 4 5 6 7 8 9 10 Note In the example, we can split: * [4, 3, 1, 2] into [4, 3, 1], [2] * [4, 5, 6, 1, 3, 2] into [4, 1], [5, 6] and [3, 2] * [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] into [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] Surely, there are many more answers possible. Submitted Solution: ``` t = int(input()) for _ in range(t): n = int(input()) arr = [] arr = [int(x) for x in input().split()] subs = [] tmp = [] for i in arr: if len(tmp) == 0 or (len(tmp) == 1 and tmp[0] != i) or (tmp[0] > tmp[len(tmp)-1] > i) or (tmp[0] < tmp[len(tmp)-1] < i): tmp.append(i) else: subs.append(tmp) tmp = [] tmp.append(i) if len(tmp) > 0: subs.append(tmp) print(len(subs)) for i in range(len(subs)): print(len(subs[i]), *subs[i]) ```
instruction
0
102,923
12
205,846
No
output
1
102,923
12
205,847
Provide tags and a correct Python 3 solution for this coding contest problem. The Little Elephant loves sortings. He has an array a consisting of n integers. Let's number the array elements from 1 to n, then the i-th element will be denoted as ai. The Little Elephant can make one move to choose an arbitrary pair of integers l and r (1 ≀ l ≀ r ≀ n) and increase ai by 1 for all i such that l ≀ i ≀ r. Help the Little Elephant find the minimum number of moves he needs to convert array a to an arbitrary array sorted in the non-decreasing order. Array a, consisting of n elements, is sorted in the non-decreasing order if for any i (1 ≀ i < n) ai ≀ ai + 1 holds. Input The first line contains a single integer n (1 ≀ n ≀ 105) β€” the size of array a. The next line contains n integers, separated by single spaces β€” array a (1 ≀ ai ≀ 109). The array elements are listed in the line in the order of their index's increasing. Output In a single line print a single integer β€” the answer to the problem. Please, do not use the %lld specifier to read or write 64-bit integers in Π‘++. It is preferred to use the cin, cout streams or the %I64d specifier. Examples Input 3 1 2 3 Output 0 Input 3 3 2 1 Output 2 Input 4 7 4 1 47 Output 6 Note In the first sample the array is already sorted in the non-decreasing order, so the answer is 0. In the second sample you need to perform two operations: first increase numbers from second to third (after that the array will be: [3, 3, 2]), and second increase only the last element (the array will be: [3, 3, 3]). In the third sample you should make at least 6 steps. The possible sequence of the operations is: (2; 3), (2; 3), (2; 3), (3; 3), (3; 3), (3; 3). After that the array converts to [7, 7, 7, 47].
instruction
0
103,133
12
206,266
Tags: brute force, greedy Correct Solution: ``` #rOkY #FuCk ################################## kOpAl ##################################### t=int(input()) l=list(map(int,input().split())) t1=l[0] sum=0 for i in range(1,t,1): if(l[i]<t1): sum+=(t1-l[i]) t1=l[i] print(sum) ```
output
1
103,133
12
206,267
Provide tags and a correct Python 3 solution for this coding contest problem. The Little Elephant loves sortings. He has an array a consisting of n integers. Let's number the array elements from 1 to n, then the i-th element will be denoted as ai. The Little Elephant can make one move to choose an arbitrary pair of integers l and r (1 ≀ l ≀ r ≀ n) and increase ai by 1 for all i such that l ≀ i ≀ r. Help the Little Elephant find the minimum number of moves he needs to convert array a to an arbitrary array sorted in the non-decreasing order. Array a, consisting of n elements, is sorted in the non-decreasing order if for any i (1 ≀ i < n) ai ≀ ai + 1 holds. Input The first line contains a single integer n (1 ≀ n ≀ 105) β€” the size of array a. The next line contains n integers, separated by single spaces β€” array a (1 ≀ ai ≀ 109). The array elements are listed in the line in the order of their index's increasing. Output In a single line print a single integer β€” the answer to the problem. Please, do not use the %lld specifier to read or write 64-bit integers in Π‘++. It is preferred to use the cin, cout streams or the %I64d specifier. Examples Input 3 1 2 3 Output 0 Input 3 3 2 1 Output 2 Input 4 7 4 1 47 Output 6 Note In the first sample the array is already sorted in the non-decreasing order, so the answer is 0. In the second sample you need to perform two operations: first increase numbers from second to third (after that the array will be: [3, 3, 2]), and second increase only the last element (the array will be: [3, 3, 3]). In the third sample you should make at least 6 steps. The possible sequence of the operations is: (2; 3), (2; 3), (2; 3), (3; 3), (3; 3), (3; 3). After that the array converts to [7, 7, 7, 47].
instruction
0
103,134
12
206,268
Tags: brute force, greedy Correct Solution: ``` n=int(input()) list1=list(map(int,input().split())) s=0 for i in range(1,n): if(list1[i]<list1[i-1]): s+=abs(list1[i]-list1[i-1]) print(s) ```
output
1
103,134
12
206,269
Provide tags and a correct Python 3 solution for this coding contest problem. The Little Elephant loves sortings. He has an array a consisting of n integers. Let's number the array elements from 1 to n, then the i-th element will be denoted as ai. The Little Elephant can make one move to choose an arbitrary pair of integers l and r (1 ≀ l ≀ r ≀ n) and increase ai by 1 for all i such that l ≀ i ≀ r. Help the Little Elephant find the minimum number of moves he needs to convert array a to an arbitrary array sorted in the non-decreasing order. Array a, consisting of n elements, is sorted in the non-decreasing order if for any i (1 ≀ i < n) ai ≀ ai + 1 holds. Input The first line contains a single integer n (1 ≀ n ≀ 105) β€” the size of array a. The next line contains n integers, separated by single spaces β€” array a (1 ≀ ai ≀ 109). The array elements are listed in the line in the order of their index's increasing. Output In a single line print a single integer β€” the answer to the problem. Please, do not use the %lld specifier to read or write 64-bit integers in Π‘++. It is preferred to use the cin, cout streams or the %I64d specifier. Examples Input 3 1 2 3 Output 0 Input 3 3 2 1 Output 2 Input 4 7 4 1 47 Output 6 Note In the first sample the array is already sorted in the non-decreasing order, so the answer is 0. In the second sample you need to perform two operations: first increase numbers from second to third (after that the array will be: [3, 3, 2]), and second increase only the last element (the array will be: [3, 3, 3]). In the third sample you should make at least 6 steps. The possible sequence of the operations is: (2; 3), (2; 3), (2; 3), (3; 3), (3; 3), (3; 3). After that the array converts to [7, 7, 7, 47].
instruction
0
103,135
12
206,270
Tags: brute force, greedy Correct Solution: ``` """ Author : co_devil Chirag Garg Institute : JIIT """ from __future__ import division, print_function import itertools, os, sys, threading from collections import deque, Counter, OrderedDict, defaultdict import heapq from math import ceil,floor,log,sqrt,factorial,pow,pi # from bisect import bisect_left,bisect_right # from decimal import *,threading """from io import BytesIO, IOBase if sys.version_info[0] < 3: from __builtin__ import xrange as range from future_builtins import ascii, filter, hex, map, oct, zip else: from builtins import str as __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._buffer = BytesIO() self._fd = file.fileno() 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): return self._buffer.read() if self._buffer.tell() else os.read(self._fd, os.fstat(self._fd).st_size) def readline(self): while self.newlines == 0: b, ptr = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE)), self._buffer.tell() self._buffer.seek(0, 2), self._buffer.write(b), self._buffer.seek(ptr) self.newlines += b.count(b'\n') + (not b) 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) sys.stdin, sys.stdout = FastIO(sys.stdin), FastIO(sys.stdout) input = lambda: sys.stdin.readline().rstrip(b'\r\n') def print(*args, **kwargs): sep, file = kwargs.pop('sep', b' '), kwargs.pop('file', sys.stdout) at_start = True for x in args: if not at_start: file.write(sep) file.write(str(x)) at_start = False file.write(kwargs.pop('end', b'\n')) if kwargs.pop('flush', False): file.flush() """ def ii(): return int(input()) def si(): return str(input()) def mi(): return map(int,input().split()) def li(): return list(mi()) abc = 'abcdefghijklmnopqrstuvwxyz' abd = {'a': 0, 'b': 1, 'c': 2, 'd': 3, 'e': 4, 'f': 5, 'g': 6, 'h': 7, 'i': 8, 'j': 9, 'k': 10, 'l': 11, 'm': 12, 'n': 13, 'o': 14, 'p': 15, 'q': 16, 'r': 17, 's': 18, 't': 19, 'u': 20, 'v': 21, 'w': 22, 'x': 23, 'y': 24, 'z': 25} mod = 1000000007 dx, dy = [-1, 1, 0, 0], [0, 0, 1, -1] def getKey(item): return item[0] def sort2(l): return sorted(l, key=getKey) def d2(n, m, num): return [[num for x in range(m)] for y in range(n)] def isPowerOfTwo(x): return (x and (not (x & (x - 1)))) def decimalToBinary(n): return bin(n).replace("0b", "") def ntl(n): return [int(i) for i in str(n)] def powerMod(x, y, p): res = 1 x %= p while y > 0: if y & 1: res = (res * x) % p y = y >> 1 x = (x * x) % p return res def gcd(x, y): while y: x, y = y, x % y return x # For getting input from input.txt file # sys.stdin = open('input.txt', 'r') # Printing the Output to output.txt file # sys.stdout = open('output.txt', 'w') graph = defaultdict(list) visited = [0] * 1000000 col = [-1] * 1000000 def dfs(v, c): if visited[v]: if col[v] != c: print('-1') exit() return col[v] = c visited[v] = 1 for i in graph[v]: dfs(i, c ^ 1) def bfs(d,v): q=[] q.append(v) visited[v]=1 while len(q)!=0: x=q[0] q.pop(0) for i in d[x]: if visited[i]!=1: visited[i]=1 q.append(i) print(x) print(l) def make_graph(e): d={} for i in range(e): x,y=mi() if x not in d.keys(): d[x]=[y] else: d[x].append(y) if y not in d.keys(): d[y] = [x] else: d[y].append(x) return d def gr2(n): d={} for i in range(n): x,y=mi() if x not in d.keys(): d[x]=[y] else: d[x].append(y) return d def connected_components(graph): seen = set() def dfs(v): vs = set([v]) component=[] while vs: v = vs.pop() seen.add(v) vs |= set(graph[v]) - seen component.append(v) return component ans=[] for v in graph: if v not in seen: d=dfs(v) ans.append(d) return ans n=ii() s=li() c=0 for i in range(1,n): c+=max(s[i],s[i-1])-s[i] print(c) ```
output
1
103,135
12
206,271
Provide tags and a correct Python 3 solution for this coding contest problem. The Little Elephant loves sortings. He has an array a consisting of n integers. Let's number the array elements from 1 to n, then the i-th element will be denoted as ai. The Little Elephant can make one move to choose an arbitrary pair of integers l and r (1 ≀ l ≀ r ≀ n) and increase ai by 1 for all i such that l ≀ i ≀ r. Help the Little Elephant find the minimum number of moves he needs to convert array a to an arbitrary array sorted in the non-decreasing order. Array a, consisting of n elements, is sorted in the non-decreasing order if for any i (1 ≀ i < n) ai ≀ ai + 1 holds. Input The first line contains a single integer n (1 ≀ n ≀ 105) β€” the size of array a. The next line contains n integers, separated by single spaces β€” array a (1 ≀ ai ≀ 109). The array elements are listed in the line in the order of their index's increasing. Output In a single line print a single integer β€” the answer to the problem. Please, do not use the %lld specifier to read or write 64-bit integers in Π‘++. It is preferred to use the cin, cout streams or the %I64d specifier. Examples Input 3 1 2 3 Output 0 Input 3 3 2 1 Output 2 Input 4 7 4 1 47 Output 6 Note In the first sample the array is already sorted in the non-decreasing order, so the answer is 0. In the second sample you need to perform two operations: first increase numbers from second to third (after that the array will be: [3, 3, 2]), and second increase only the last element (the array will be: [3, 3, 3]). In the third sample you should make at least 6 steps. The possible sequence of the operations is: (2; 3), (2; 3), (2; 3), (3; 3), (3; 3), (3; 3). After that the array converts to [7, 7, 7, 47].
instruction
0
103,136
12
206,272
Tags: brute force, greedy Correct Solution: ``` n=int(input()) a=[int(x) for x in input().split()] ans=0 for i in range(n-1): if a[i+1]<a[i]: ans+=a[i]-a[i+1] print(ans) ```
output
1
103,136
12
206,273
Provide tags and a correct Python 3 solution for this coding contest problem. The Little Elephant loves sortings. He has an array a consisting of n integers. Let's number the array elements from 1 to n, then the i-th element will be denoted as ai. The Little Elephant can make one move to choose an arbitrary pair of integers l and r (1 ≀ l ≀ r ≀ n) and increase ai by 1 for all i such that l ≀ i ≀ r. Help the Little Elephant find the minimum number of moves he needs to convert array a to an arbitrary array sorted in the non-decreasing order. Array a, consisting of n elements, is sorted in the non-decreasing order if for any i (1 ≀ i < n) ai ≀ ai + 1 holds. Input The first line contains a single integer n (1 ≀ n ≀ 105) β€” the size of array a. The next line contains n integers, separated by single spaces β€” array a (1 ≀ ai ≀ 109). The array elements are listed in the line in the order of their index's increasing. Output In a single line print a single integer β€” the answer to the problem. Please, do not use the %lld specifier to read or write 64-bit integers in Π‘++. It is preferred to use the cin, cout streams or the %I64d specifier. Examples Input 3 1 2 3 Output 0 Input 3 3 2 1 Output 2 Input 4 7 4 1 47 Output 6 Note In the first sample the array is already sorted in the non-decreasing order, so the answer is 0. In the second sample you need to perform two operations: first increase numbers from second to third (after that the array will be: [3, 3, 2]), and second increase only the last element (the array will be: [3, 3, 3]). In the third sample you should make at least 6 steps. The possible sequence of the operations is: (2; 3), (2; 3), (2; 3), (3; 3), (3; 3), (3; 3). After that the array converts to [7, 7, 7, 47].
instruction
0
103,137
12
206,274
Tags: brute force, greedy Correct Solution: ``` #coding=utf-8 import sys n=int(input()) a=[int(i) for i in input().split()] i=n-1 sum=0 while i>0: if a[i]<a[i-1]: sum+=a[i-1]-a[i] i-=1 print(sum) ```
output
1
103,137
12
206,275
Provide tags and a correct Python 3 solution for this coding contest problem. The Little Elephant loves sortings. He has an array a consisting of n integers. Let's number the array elements from 1 to n, then the i-th element will be denoted as ai. The Little Elephant can make one move to choose an arbitrary pair of integers l and r (1 ≀ l ≀ r ≀ n) and increase ai by 1 for all i such that l ≀ i ≀ r. Help the Little Elephant find the minimum number of moves he needs to convert array a to an arbitrary array sorted in the non-decreasing order. Array a, consisting of n elements, is sorted in the non-decreasing order if for any i (1 ≀ i < n) ai ≀ ai + 1 holds. Input The first line contains a single integer n (1 ≀ n ≀ 105) β€” the size of array a. The next line contains n integers, separated by single spaces β€” array a (1 ≀ ai ≀ 109). The array elements are listed in the line in the order of their index's increasing. Output In a single line print a single integer β€” the answer to the problem. Please, do not use the %lld specifier to read or write 64-bit integers in Π‘++. It is preferred to use the cin, cout streams or the %I64d specifier. Examples Input 3 1 2 3 Output 0 Input 3 3 2 1 Output 2 Input 4 7 4 1 47 Output 6 Note In the first sample the array is already sorted in the non-decreasing order, so the answer is 0. In the second sample you need to perform two operations: first increase numbers from second to third (after that the array will be: [3, 3, 2]), and second increase only the last element (the array will be: [3, 3, 3]). In the third sample you should make at least 6 steps. The possible sequence of the operations is: (2; 3), (2; 3), (2; 3), (3; 3), (3; 3), (3; 3). After that the array converts to [7, 7, 7, 47].
instruction
0
103,138
12
206,276
Tags: brute force, greedy Correct Solution: ``` n=int(input()) l=list(map(int,input().split())) cnt=0 ans=0 for i in range(1,n): if l[i]+cnt<l[i-1]: ans+=abs(l[i]+cnt-l[i-1]) cnt+=ans l[i]+=cnt print(ans) ```
output
1
103,138
12
206,277
Provide tags and a correct Python 3 solution for this coding contest problem. The Little Elephant loves sortings. He has an array a consisting of n integers. Let's number the array elements from 1 to n, then the i-th element will be denoted as ai. The Little Elephant can make one move to choose an arbitrary pair of integers l and r (1 ≀ l ≀ r ≀ n) and increase ai by 1 for all i such that l ≀ i ≀ r. Help the Little Elephant find the minimum number of moves he needs to convert array a to an arbitrary array sorted in the non-decreasing order. Array a, consisting of n elements, is sorted in the non-decreasing order if for any i (1 ≀ i < n) ai ≀ ai + 1 holds. Input The first line contains a single integer n (1 ≀ n ≀ 105) β€” the size of array a. The next line contains n integers, separated by single spaces β€” array a (1 ≀ ai ≀ 109). The array elements are listed in the line in the order of their index's increasing. Output In a single line print a single integer β€” the answer to the problem. Please, do not use the %lld specifier to read or write 64-bit integers in Π‘++. It is preferred to use the cin, cout streams or the %I64d specifier. Examples Input 3 1 2 3 Output 0 Input 3 3 2 1 Output 2 Input 4 7 4 1 47 Output 6 Note In the first sample the array is already sorted in the non-decreasing order, so the answer is 0. In the second sample you need to perform two operations: first increase numbers from second to third (after that the array will be: [3, 3, 2]), and second increase only the last element (the array will be: [3, 3, 3]). In the third sample you should make at least 6 steps. The possible sequence of the operations is: (2; 3), (2; 3), (2; 3), (3; 3), (3; 3), (3; 3). After that the array converts to [7, 7, 7, 47].
instruction
0
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Tags: brute force, greedy Correct Solution: ``` n = int(input()) a = list(map(int, input().split())) print(sum(max(0,a[i-1]-a[i]) for i in range(1,n))) # Made By Mostafa_Khaled ```
output
1
103,139
12
206,279