HDU 1160 FatMouse's Speed

题解：最长上升子序列的应用，按w升序,s降序排列后进行DP找最长序列,用pre[]数组记录该点的前驱,从而打印路径

#include <cstdio>  
#include <algorithm>  
using namespace std;  
struct mouse{  
    int w,s,id;  
    bool operator<(const mouse& m) 
    const{  
        return w<m.w||(w==m.w&&s>m.s);    
    }     
}m[1005];  
int d[1005],pre[1005],ms=1,ans[1005];  
void solve(){  
    d[0]=-1;  
    int head=0;  
    for(int i=1;i<=ms;i++){  
        int t=0;  
        for(int j=1;j<i;j++){  
            if(m[i].w>m[j].w&&m[i].s<m[j].s&&d[j]+1>d[t]+1){  
                t=j;  
            }     
        }  
        if(t==0)d[i]=1,pre[i]=-1;  
        else{  
            d[i]=d[t]+1;  
            pre[i]=t;  
        }  
        if(d[i]>d[head])head=i;   
    }       
    int as=0;  
    while(head!=-1){  
        ans[as++]=m[head].id;  
        head=pre[head];     
    }  
    printf("%d
",as);  
    for(int i=as-1;i>=0;i--)printf("%d
",ans[i]);  
}  
int main()
{  
    while(scanf("%d%d",&m[ms].w,&m[ms].s)!=EOF)m[ms].id=ms,ms++;  
    sort(m+1,m+ms+1);        
    solve();  
    return 0;     
}