hdu 1878

http://acm.hdu.edu.cn/showproblem.php?pid=1878

题意：就是判断这个图是不是一个欧拉回路的一个题，

思路：我觉得这个题可以用并查集判环加上判断每个点的度就行了

 #include <stdio.h>
 #include <string.h>
 #include <queue>
 using namespace std;
 int graph[];
 int belg[];

 int Find(int x)
 {
     int _x=x,_b;
     while( _x != belg[ _x ] )
         _x = belg[ _x ];
     while( x != belg[ x ] )
     {
         _b = belg[ x ];
         belg[ x ] = _x;
         x = _b;
     }
     return _x;
 }

 void unio(int x,int y)
 {
     int root1 = Find(x);
     int root2 = Find(y);
     if( root1 != root2 ) belg[root2] = root1;
 }

 int main()
 {
     int n,m,a,b;
     while(scanf("%d",&n)&&n)
     {
         int falg = ,mark;
         scanf("%d",&m);
         memset(graph,false,sizeof(graph));
         for(int i =  ; i <= n ; i++)
             belg[i] = i;
         for(int i =  ; i <= m ; i++ )
         {
             scanf("%d%d",&a,&b);
             unio(a,b);
             graph[a]++;
             graph[b]++;
         }
         mark  = belg[];
         for(int i =  ; i <= n ; i++)
         {
             if(belg[i]!=mark||(graph[i]&)) {
                 falg = ;
                 break;
             }
         }
         if(falg) printf("1\n");
         else printf("0\n");
     }
 }