UVA Morning Walk（判欧拉回路）

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include<iostream>
#include<algorithm>

using namespace std;

#define M 210


int num[M];

int findx(int x)
{
    int r = x;
    while(r!=num[r])
    {
        r = num[r];
    }
    int k = x,j;
    while(k!=r)
    {
        j = num[k];
        num[k] = r;
        k = j;
    }
    return r;
}

void bing(int x,int y)
{
    int fx = findx(x);
    int fy = findx(y);
    if(fx!=fy)
    {
        num[fx] = fy;
    }

}

int main()
{
    int t, k = 1;
    int v[M];
    int n,m;
    while(scanf("%d%d",&n,&m)!=EOF)
    {
        for (int i = 0; i < n; i++)
        {
            num[i] = i;
            v[i] = 0;
        }

        for (int i = 0; i < m; i++)
        {
            int a, b;
            scanf("%d%d", &a, &b);
            v[a]++;
            v[b]++;
            bing(a,b);
        }
        int cnt = 0;
        for (int i = 0; i < n; i++)
        {
            if (num[i] == i && v[i]!=0)
            {
                cnt++;
            }
        }
        int sum = 0;
        if(cnt == 1 && m>=2)
        {
            for(int i=0; i<n; i++)
            {
                if(v[i]%2!=0)
                {
                    sum++;
                    //printf("i = %d\n",i);
                    break;
                }
            }
            if (sum > 0)
            {
                printf("Not Possible\n");
            }
            else
            {
                printf("Possible\n");
            }
        }
        else
        {
            printf("Not Possible\n");
        }

    }
    return 0;
}