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[1005];
int belg[1005];


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