权威题解|枚举

这个就叫做无脑

#include<iostream>
using namespace std;
int main() {
    int n;
    cin >> n;
    int arr[2500]; 
    for(int i = 0; i < n; i++) {
        cin >> arr[i];
    }  
    int base = 0; 
    for(int i = 0; i < n; i++) {
        if(arr[i] == 1) base++;
    }   
    int max_gain = 0; 
    for(int i = 0; i < n; i++) {
        int zeros = 0, ones = 0;
        for(int j = i; j < n; j++) {
            if(arr[j] == 0) zeros++;
            else ones++;
            int gain = zeros - ones;
            if(gain > max_gain) {
                max_gain = gain;
            }
        }
    }
    if(max_gain>0)cout << base + max_gain ;
    else cout<<base-1;
}

注意：题目要求必须要进行一次操作
所以当序列全为一时输出要减1；