Hangdian 1087 (dynamic programming)

#include<stdio.h>
#include<stdio.h>
#include<string.h>
#include<iostream>
#include <algorithm>
using namespace std;
#define MAX 1010
const int INF = 0x3f3f3f3f;
int a[MAX];
int dp[MAX];
int n;
int main()
{
    
    
    int n,s,ans;
    while(scanf("%d",&n)==1&&n)
    {
    
    
        ans=-INF;
        memset(dp,0,sizeof(dp));
        memset(a,0,sizeof(a));
        for(int i=1;i<=n;i++)
        {
    
    
            scanf("%d",&a[i]);
        }
        for(int i=1;i<=n;i++)
        {
    
    
            s=-INF;
            for(int j=1;j<i;j++)
            {
    
    
                if(a[j]<a[i])
                {
    
    
                    //运用上一步找到的结果求下一步的最优解。
                    s = s>dp[j]?s:dp[j];
                }
            }
            //cout<<s<<endl;
            if(s==-INF)
            {
    
    
                dp[i]=a[i];
            }
            else
            dp[i]=a[i]+s;
            ans=ans>dp[i]?ans:dp[i];
        }
        cout<<ans<<endl;
    }
    return 0;
}