欧拉路径问题

#include<cstdio>
#include<cstring>


int n,m;
int e[100][100];
int top;
int stack[100];
void dfs(int x){
    top ++;
    stack[top] = x;
    for(int i = 1; i <= n; i ++){
        if(e[x][i] > 0){
            e[i][x] = e[x][i] = 0;//删除此边
            dfs(i);
            break;
        }
    }
}
void fleury(int x){
    top = 0;
    stack[top] = x;
    while(top >= 0){
        int b = 0;
        for(int i = 1; i <= n; i ++){
            if(e[stack[top]][i] > 0){
                b=1;
                break;
            }
        }
        if(b == 0){//如果没有可以扩展就输出并出栈
            printf("%d->",stack[top]);
            top--;
        }
        else{
            top--;
            dfs(stack[top+1]);
        }
    }
    puts("");
}
int main()
{
    int degree, num, start;//顶点的度，奇度顶点个数，欧拉回路的起点
    while(~scanf("%d%d", &n, &m)){
        memset(e, 0, sizeof(0));
        for(int i = 0; i < m; i ++){
            int s, t;
            scanf("%d%d", &s, &t);
            e[s][t] = e[t][s] = 1;
        }
        num = 0, start = 1;
        //如果存在奇度顶点，则从奇度顶点出发，否则从顶点0出发
        for(int i = 1; i <= n; i ++){
            degree = 0;
            for(int j = 1; j <= n; j ++){
                degree += e[i][j];
            }
            if(degree%2) start = i, num++;
        }
        if(num == 0||num == 2) fleury(start);
        else
            puts("no");
    }
    return 0;
}
/*
9 14
1 2
1 8
2 3
2 8
2 9
3 4
4 5
4 6
4 9
5 6
6 7
6 9
7 8
8 9

7 11
1 5
1 4
7 3
7 5
7 6
7 2
5 6
5 2
4 2
4 3
4 6

*/