282石子合并

类似于二分法？
每一部分求到最小值然后合并

#include<bits/stdc++.h>
using namespace std;

const int N = 310;
int n;
int s[N];
int f[N][N];

int main() {
    cin >> n;
    for (int i = 1; i <= n; i ++) cin >> s[i];
    for (int i = 1; i <= n; i ++) s[i] += s[i - 1];
    
    for (int len = 2; len <= n; len ++) {  // len是区间长度
        for(int i = 1; i + len - 1 <= n; i++) {
            int l = i, r = i + len - 1;
            f[l][r] = 1e9;
            for (int k = l; k < r; k ++) {
                f[l][r] = min(f[l][r], f[l][k] + f[k + 1][r] + s[r] - s[l - 1]);
            }
        }
    }
    cout << f[1][n];
}