51Nod 1021 石子归并（动态规划）

 #include <iostream>
 #include <algorithm>
 #include <string>
 #include <iostream>

 #define INF 0xfffffff
 using namespace std;
 const int maxn =  + ;
 int a[maxn];
 int sum[maxn];
 int dp[maxn][maxn];
 //dp[i][j]    从i到j所需的最少

 int main(){
     ios::sync_with_stdio(false);
     /*
     freopen("in.txt", "r", stdin);
     freopen("out.txt", "w", stdout);
     */
     int n;
     cin >> n;
     for (int i = ; i <= n; i++){
         cin >> a[i];
         sum[i] = sum[i - ] + a[i];
     }
     //init

     for (int l = ; l <= n; l++){
         //中间的长度
         for (int sta = ; sta <= n - l + ; sta++){
             int endd = sta + l - ;
             int Min = INF;
             for (int k = sta; k < endd; k++){
                 if (dp[sta][k] + dp[k + ][endd] + sum[endd] - sum[sta - ] < Min){
                     Min = dp[sta][k] + dp[k + ][endd] + sum[endd] - sum[sta - ];
                 }
             }
             dp[sta][endd] = Min;
         }
     }
     cout << dp[][n] << endl;

     //fclose(stdin);
     //fclose(stdout);
     system("pause");
     return ;
 }