poj 3186 Treats for the Cows(dp)

#include<cstdio>
#include<cString>
#include<algorithm>
#include<iostream>
#include<String>
#include<vector>
#include<stack>
#include<bitset>
#include<cstdlib>
#include<cmath>
#include<set>
#include<list>
#include<deque>
#include<map>
#include<queue>
#define ll long long int
using namespace std;
inline ll gcd(ll a,ll b){return b?gcd(b,a%b):a;}
inline ll lcm(ll a,ll b){return a/gcd(a,b)*b;}
int moth[13]={0,31,28,30,31};
int dir[4][2]={1,0,1,-1,-1};
int dirs[8][2]={1,1};
const int inf=0x3f3f3f3f;
const ll mod=1e9+7;
int a[2007];
int dp[2007][2007];
int main(){
    ios::sync_with_stdio(false);
    int n;
    while(cin>>n){
        memset(dp,0,sizeof(dp));
        for(int i=1;i<=n;i++){
            cin>>a[i];
        //    sum[i]+=a[i];
        }
        dp[1][0]=a[n];
        dp[1][1]=a[1];
        for(int i=2;i<=n;i++){
            for(int j=n;j>=n-i+1;j--)
            dp[i][0]+=(a[j]*(n-j+1));
            for(int j=1;j<=i;j++){
                if(dp[i-1][j-1]+a[j]*i<dp[i-1][j]+a[n-(i-1-j)]*i){
                    dp[i][j]=dp[i-1][j]+a[n-(i-1-j)]*i;
                }else{
                    dp[i][j]=dp[i-1][j-1]+a[j]*i;
                }
            }
        }
        int ans=-inf;
        for(int i=0;i<=n;i++)
            ans=@H_540_81@max(dp[n][i],ans);
        cout<<ans<<endl;
    }
    return 0;
}