欧拉回路

#include<iostream>
#include<vector>
#include<algorithm>
#include<string>
#include<stdio.h>
using namespace std;
#define maxLen 1001
class node{
public:
    vector<int> list; //用邻接表来存储图
    int count(){
        return list.size();
    }
    void push(int index){
        list.push_back(index);
    }
    int pop(){
        int index = list.back();
        list.pop_back();
        return index;
    }
    void clear(){
        list.clear();
    }
};
int main(){
    int N;
    int M;
    vector<int> result;
    node vertex[maxLen+1];//从下表1开始
    while (true){
        cin >> N;
        if (N == 0){
            break;
        }
        else{
            cin >> M;
            for (int i = 0; i < M; ++i){
                int v1, v2;
                cin >> v1 >> v2;
                vertex[v1].push(v2);
                vertex[v2].push(v1);
            }
            int j;
            for (j = 0; j < N; ++j){
                if (vertex[j].count() % 2 != 0){
                    break;
                }
            }
            if (j == N){
                result.push_back(1);
            }
            else{
                result.push_back(0);
            }
        }
    }
    for (int i = 0; i < result.size(); ++i){
        cout << result[i] << endl;
    }
    system("pause");
    return 0;
}