使用前后缀和寻找数组平衡点下标

```cpp #include <iostream> using namespace std; int n; int a[100010]; int sum1[100010]; //sum1为前缀和数组 int sum2[100010]; //sum2为后缀和数组 int main() { cin >> n; for (int i = 1; i <= n; i++) { cin >> a[i]; sum1[i] = sum1[i - 1] + a[i]; } for (int i = n; i >= 1; i--) { sum2[i] = sum2[i + 1] + a[i]; } for (int i = 1; i <= n; i++) { if (sum1[i - 1] == sum2[i + 1]) { cout << i << endl; return 0; } } return 0; } ``` ######[AI问答 | 242点数解答 | 2026-05-30 19:36:31]