我用的前缀和的思想

但测试点2

RE 啦

#include <iostream>
#include <cmath>
#include <vector>
#include <cstring>
#include <string>
#include <algorithm>
#include <cstdlib>

using namespace std;
/*    +--------------------------+
     /                          /|
    +--------------------------+ |
    |                          | |
    |  +====================+  | |
    |  |                    |  | |
    |  |                    |  | |
    |  |                    |  | |
    |  |                    |  | |
    |  |                    |  | |
    |  |                    |  | |                 消失在茫茫历史里的街机
    |  |                    |  | |
    /  |                 O  |  / |                 就是我们
    +  +=================|==+ |  |
   /                   __|__  /  |                 逝去的青春 ~
  /                     ###  /   |
  +--------------------------|   |
  |          Insert          |   |
  |          The Coin(s) Here|   |
  |                  /--\    |   |
  |                  || |    |   |
  |  ----------      +==+    |   /
  |  ----------      || |    |  /
  |  ----------      \==/    | /
  |                          |/
  +--------------------------+*/
int a[1010];
int main() {
	int n, m;
	cin >> n >> m;
	for (int i = 1; i <= n; i++) {
		cin >> a[i];
		a[i] += a[i - 1];
	}
	int min = 3000002;
	for (int i = m; i <= n; i++) {
		int t = a[i] - a[i - m - 1 + 1];
		if (t < min) {
			min = t;
		}
	}
	cout << min;
	return 0;
}

求大佬帮助