CF #4 D - Mysterious Present 最近怎么那么弱

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cmath>
using namespace std;
const int maxn=5012;
struct node
{
    int wi,hi,id;
}p[maxn];
int n,w,h,ans,path[maxn];
int cmp(node a,node b)
{
    if(a.wi!=b.wi)return a.wi<b.wi;
    return a.hi<=b.hi;
}
int dp[maxn];
void dfs(int key)
{
    if(path[key]==-1)
    {
       //cout<<"OK ";
       cout<<p[key].id<<" ";return;
    }
    dfs(path[key]);
    cout<<p[key].id<<" ";
}
int main()
{
    while(scanf("%d%d%d",&n,&w,&h)!=EOF)
    {
        int i,j,key=0;
        ans=0;
        memset(path,-1,sizeof(path));
        for(i=1;i<=n;i++)
        {
            scanf("%d%d",&p[i].wi,&p[i].hi);
            p[i].id=i;
            dp[i]=0;
        }
        sort(p+1,p+n+1,cmp);
        for(i=1;i<=n;i++)
        {
            if(p[i].wi>w&&p[i].hi>h)
            {
                dp[i]=1,path[i]=-1;
                if(!ans) ans=dp[i],key=i;
            }

            for(j=i-1;j>=1;j--)
            {
                if(dp[j]&&p[j].wi<p[i].wi&&p[j].hi<p[i].hi)
                {
                    if(dp[i]<dp[j]+1)
                    {
                        dp[i]=dp[j]+1;
                        path[i]=j;
                        if(ans<dp[i])ans=dp[i],key=i;
                    }
                }
            }
        }
        cout<<ans<<endl;
        if(ans)
        {
            dfs(key);cout<<endl;
        }
    }
    return 0;
}
/*
5 10 10
22 23
17 19
13 17
8 12
2 6

3 3 3
5 4
12 11
9 8

2 1 1
2 2
2 2

4 12 140
172 60
71 95
125 149
53 82

*/