tyvj1198 最优矩阵连乘

#include<iostream>
#include<cstdio>
#include<string>
#include<cstring>
#include<algorithm>
#include<vector>
using namespace std;
const long long maxn = 105,maxint = 98765432123456L;
long long n,a[maxn],f[maxn][maxn];
int main(){
    cin>>n;
    for(int i = 1;i <= n+1;i++){
        cin>>a[i];
    }
    for(int i = 1;i <= n+1;i++){
        for(int j = 1;j <= n+1;j++){
            f[i][j] = maxint;
        }
    }
    long long j,tmp;
    for(int l = 3;l <= n+1;l++){
        for(int i = 1;i <= n-1;i++){
            j = i + l - 1;
            for(int k = i + 1;k <= j-1;k++){
                tmp = a[i] * a[k] * a[j];
                if(k - i >= 2) tmp += f[i][k];
                if(j - k >= 2) tmp += f[k][j];
                f[i][j] = min(f[i][j],tmp);
            }
        }
    }
    cout<<f[1][n+1];
    return 0;
}