HDU 1878 欧拉回路

#include <iostream>
#include <cstring>
#include <cstdio>
#include <algorithm>
#include <queue>
#include <vector>
#include <iomanip>
#include <math.h>
#include <map>
using namespace std;
#define FIN     freopen("input.txt","r",stdin);
#define FOUT    freopen("output.txt","w",stdout);
#define INF     0x3f3f3f3f
#define lson    l,m,rt<<1
#define rson    m+1,r,rt<<1|1
typedef long long LL;

const int MAXN=1000+5;

int DU[MAXN];
int n,m,sz;
int father[MAXN];

void edge_init(){
   memset(DU,0,sizeof(DU));
   for(int i=1;i<=n;i++){
       father[i]=i;
   }
}


int Find(int x){
    if(x!=father[x]){
        father[x]=Find(father[x]);
    }
    return father[x];
}

int main()
{
    //FIN
    while(~scanf("%d",&n),n)
    {
        scanf("%d",&m);
        edge_init();
        int sum=n;
        for(int i=1;i<=m;i++){
            int u,v;
            scanf("%d%d",&u,&v);
            DU[u]++;
            DU[v]++;
            int root1=Find(u);
            int root2=Find(v);
            if(root1!=root2){
                father[root2]=root1;
                sum--;
            }

        }
        if(sum!=1){
            printf("0\n");
            continue;
        }

        bool flag=1;
        for(int i=1;i<=n;i++){
            if(DU[i]%2==1){
                flag=0;
                printf("0\n");
                break;
            }
        }
        if(flag)  printf("1\n");


    }
    return 0;
}