石子合并(弱化版) - 洛谷
/*
* @Description: To iterate is human, to recurse divine.
* @Autor: Recursion
* @Date: 2022-04-05 10:48:41
* @LastEditTime: 2022-04-05 11:52:33
*/
#include <bits/stdc++.h>
#define LL long long
using namespace std;
const int maxn = 1e6 + 10;
const int mod = 1e9 + 7;
const int INF = 1e9 + 10;
const int N = 4e3 + 10;
int n,ans;
int a[N],dp[N][N],sum[N];
int main()
{
ios::sync_with_stdio(false);
cin >> n;
memset(dp,0x3f,sizeof(dp));//初始化1,因为是求最小代价,所以初始化设为很大的一个数,为了后面更新。
for(int i = 1;i <= n;i ++){
cin >> a[i];
dp[i][i]=0;//初始化2,他自己本身的代价为0。
}
for(int i = 1;i <= n;i ++)
sum[i] = sum[i -1] + a[i];
// for(int i = 1;i <= n;i ++)
// cout << sum[i] << endl;
for(int len = 2;len <= n;len ++)
for(int i = 1;i + len - 1 <= n;i ++){
int j = i + len - 1;
//dp[i][j] = maxn;
for(int k = i;k < j;k ++)
dp[i][j] = min(dp[i][j], dp[i][k] + dp[k + 1][j] + sum[j] - sum[i - 1]);
}
// for(int i = 1; i<= n;i ++){
// for(int j = 1; j <= n;j ++)
// cout << dp[i][j] << " ";
// cout << endl;
// }
cout << dp[1][n] << endl;
return 0;
}