Codeforces 327A-Flipping Game（暴力枚举） - c++编程基础

A. Flipping Game time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output

Iahub got bored, so he invented a game to be played on paper.

He writes n integers a1,?a2,?...,?an. Each of those integers can be either 0 or 1. He's allowed to do exactly one move: he chooses two indices i and j (1?≤?i?≤?j?≤?n) and flips all values ak for which their positions are in range [i,?j] (that is i?≤?k?≤?j). Flip the value of xmeans to apply operation x?=?1 - x.

The goal of the game is that after exactly one move to obtain the maximum number of ones. Write a program to solve the little game of Iahub.

Input

The first line of the input contains an integer n (1?≤?n?≤?100). In the second line of the input there are n integers: a1,?a2,?...,?an. It is guaranteed that each of those n values is either 0 or 1.

Output

Print an integer ― the maximal number of 1s that can be obtained after exactly one move.

Sample test(s) input

5
1 0 0 1 0

output

input

4
1 0 0 1

output

题意：翻牌游戏。给出n张牌，每张牌只有0和1两种状态。给出初始状态。对于翻牌操作这样规定：每次操作可将区间[i,j](1=
  

   枚举区间+遍历区间判断，O（n^3）;

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                   using namespace std; const int INF=0x3f3f3f3f; #define LL long long int a[110]; int main() { int n,num[2]; while(~scanf("%d",&n)) { int ans=0; for(int i=0;i
                  
                   num[1]) ans=max(ans,pos+num[0]-num[1]); } printf("%d\n",ans); } return 0; }