hdu1878-并查集，欧拉回路

#include<iostream>
#include<algorithm>
#include<cstring>
#include<cstdio>
#define maxn 2010
using namespace std;
int f[maxn];
int findf(int x)
{
    if(f[x]==x)
        return x;
    else return findf(f[x]);
}
void join(int x,int y)
{
    int t1,t2;
    t1=findf(x);
    t2=findf(y);
    if(t1!=t2)
        f[t2]=t1;
}
int main()
{
    int n;
    int degree[maxn];
    int m;
    int cnt;
    int x,y;
    int flag;
    while(scanf("%d%d",&n,&m)!=EOF)
    {
        if(n==0)
            break;
        cnt=0,flag=0;
        memset(degree,0,sizeof(degree));
        for(int i=1;i<=n;i++)
            f[i]=i;
        for(int i=1;i<=m;i++)
        {
            scanf("%d%d",&x,&y);
            join(x,y);
            degree[y]++;
            degree[x]++;
        }
        for(int i=1;i<=n;i++)
        {
            if(f[i]==i)
                cnt++;
        }
        for(int i=1;i<=n;i++)
        {
            if(degree[i]%2==1)
                flag=1;
        }
        if(cnt==1&&flag==0)
            printf("1\n");
        else
            printf("0\n");
    }
    return 0;
}