sicily 1345 能量项链

先模拟一下确定理解题意，然后再找状态转移方程，注意方向~

//sicily 1345 能量项链
#include <bits/stdc++.h>

using namespace std;

int a[205];
int dp[205][205];

int main()
{
    int n;
    while(cin >> n)
    {
        memset(dp, 0, sizeof(dp));
        for(int i=0; i<n; i++)
        {
            cin >> a[i];
            a[i+n] = a[i];
        }
        for (int i=2*n-1; i>=0; i--) 
        {  
            for (int j=i+2; j<2*n; j++) 
            {  
                for (int k=i+1; k < j; k++) 
                    dp[i][j] = max(dp[i][j], dp[i][k]+dp[k][j]+a[i]*a[j]*a[k]);
            }  
        } 
        int maxx=0;
        for (int i=0; i<n; i++) 
        {  
            maxx = max(maxx, dp[i][i+n]);
        }  
          
        printf("%d\n", maxx);   
    }
    return 0;
}