题解

代码如下：

#include <iostream>
#include <vector>
#include <climits>
using namespace std;
int main() {
    int n;
    cin >> n;
    vector<long long> a(n);
    for (int i = 0; i < n; ++i) {
        cin >> a[i];
    }
    vector<long long> prefix(n + 1, 0);
    for (int i = 0; i < n; ++i) {
        prefix[i + 1] = prefix[i] + a[i];
    }
    vector<vector<long long>> dp(n, vector<long long>(n, 0));
    for (int len = 2; len <= n; ++len) {
        for (int l = 0; l <= n - len; ++l) {
            int r = l + len - 1;
            dp[l][r] = LLONG_MAX;
            for (int k = l; k < r; ++k) {
                long long cost = dp[l][k] + dp[k + 1][r] + prefix[r + 1] - prefix[l];
                if (cost < dp[l][r]) {
                    dp[l][r] = cost;
                }
            }
        }
    }
    cout << dp[0][n - 1] << endl;
    return 0;
}