第二题： #include<iostream> (5488)#include<vector> #include<algorithm> using namespace std; int main() { int N; cin >> N; vector<int> v(N); int sum = 0; for (int i = 0; i < N; i++) { cin >> v[i]; sum += v[i]; } int flag = -1; if (v[0] == 0) flag = 1; int cur = flag; int max1 = cur; for (int i = 1; i < N; i++) { flag = -1; if (v[i] == 0) flag = 1; cur = max(flag, cur + flag); max1 = max(max1, cur); } cout << sum + max1 << endl; }