Hdu1272 the maze of xiao xi (query set)

Question link: http://acm.hdu.edu.cn/showproblem.php? PID = 1, 1272

Note:

1. cannot be a ring, that is, the two numbers of root nodes entered each time cannot be the same;

2. There is only one maze, that is, the number of root nodes is unique;

3. Note that "yes" must be output when only "0 0" is input ";

4. Recursive stack overflow is used for State compression.

Reference code:

#include<stdio.h>int fa[100001];int find(int u){    int s;    s=u;     while (fa[u]!=u)u=fa[u];     while (fa[s]!=s){fa[s]=u;s=fa[s];}      return u;}int main(){    int u,v,x,y,n,m,i,k;    bool bo;    scanf("%d%d",&u,&v);    while (u!=-1)    {       if (u!=0)         {          for (i=1;i<=100000;i++) fa[i]=i;           bo=true;             while (u)               {                 x=find(u);y=find(v);                if (x==y) {bo=false;}                else fa[x]=y;                scanf("%d%d",&u,&v);               }            if (!bo) printf("No\n");              int j;                if(bo)                  {                    for (i=1;i<=100000;i++)                      if (find(i)!=i) break;                    for (j=i+1;j<=100000;j++)                      if ((find(j)!=j)&&(find(j)!=find(i)))                        {                           printf("No\n");                             bo=false;                           break;                        }                  }            if (bo) printf("Yes\n");        }        else printf("Yes\n");      scanf("%d%d",&u,&v);    }   return 0;}<strong></strong>

Please refer to: http://blog.csdn.net/yzj577/article/category/2432227