f[i][j]:只剩第i个到第j个时,将其取完获得的最大价值.
#include <algorithm>
#include <cmath>
#include <cstdio>
#include <cstring>
#include <iostream>
#include <vector>
using namespace std;
const int INF = 1e9;
int f[2005][2005];
int a[2005];
int main() {
// freopen("in.txt","r",stdin);
// freopen("out.txt","w",stdout);
int n;
cin>>n;
for(int i=1;i<=n;++i){
cin>>a[i];
f[i][i]=n*a[i];
}
for(int i=1;i<n;++i){
for(int l=1;l+i<=n;++l){
int r=l+i;
f[l][r]=max(f[l+1][r]+(n-i)*a[l],f[l][r-1]+(n-i)*a[r]);
}
}
cout<<f[1][n]<<endl;
return 0;
}