POJ 3186 Treats for the Cows 一个简单DP

#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<cmath>
#include<algorithm>
#include<cstring>
#include<cstring>
#include<vector>
#include<queue>
#include<stack>
using namespace std;
int v[2005];
int dp[2005][2005];
int main()
{
    int n;
    scanf("%d",&n);
    for(int i=1;i<=n;++i)
      scanf("%d",&v[i]);
    memset(dp,0,sizeof(dp));
    for(int k=n-1;k>=1;--k)
    {
        for(int i=1;i+k-1<=n;++i)
        {
            if(i>1)
            dp[i][i+k-1]=max(dp[i][i+k-1],dp[i-1][i+k-1]+v[i-1]*(n-k));
            if(i+k-1<n)
            dp[i][i+k-1]=max(dp[i][i+k-1],dp[i][i+k]+v[i+k]*(n-k));
        }
    }
    int ans=0;
    for(int i=1;i<=n;i++)
       ans=max(ans,dp[i][i]+v[i]*n);
    printf("%d\n",ans);
    return 0;
}