题解 | #丢手绢#

#include

using namespace std;

int main() { int n, sum = 0, t = 0; cin >> n;

int a[n];
for(int i = 0; i < n; i++) cin >> a[i], sum += a[i];

int l = 0, r = 0, ret = 0;
for(l; l < n; l++)
{
    while(t < sum / 2)
    {
        t += a[r % n];
        r ++;
    }
    
    if(t == sum / 2){cout << t; return 0;}
    if(t > sum / 2) ret = max(ret, min(t, sum - t));
    
    t -= a[l];
}

cout << ret;

return 0;

}

当对r限制到小于n时会导致错误。