小希的迷宫

 

#include<stdio.h>#include<string.h>int p[100005],s[100005];int find(int i){    if(p[i]!=i) p[i]=find(p[i]);    return p[i];}int main(void){    int i,j,a,b,f=0,t,f1=0;    memset(s,0,sizeof(s));    for(i=1;i<=100000;i++)        p[i]=i;    while(scanf("%d%d",&a,&b)!=EOF&&(a!=-1||b!=-1))    {        if(a==0&&b==0)        {            for(i=1;i<=100000;i++)            if(s[i]==1) {t=find(i);break;}            for(j=i+1;j<=100000;j++)            if(s[j]==1&&find(j)!=t) {f1=1;break;}            if(f==0&&f1==0) printf("Yes\n");            else printf("No\n");            memset(s,0,sizeof(s));            f=0;f1=0;            for(i=1;i<=100000;i++)                p[i]=i;        }        else        {s[a]=1;s[b]=1;            a=find(a);            b=find(b);            if(a==b) f=1;            else p[b]=a;        }    }    return 0;}