C语言代码，采用邻接矩阵存储无向图

#include <stdio.h>
int book[110] = {0}, e[110][110];
int n;
int que[10010], head, tail;

int main()
{
    scanf("%d", &n);

    int i, j;
    for(i = 1; i <= n; i++)
    {
        for(j = 1; j <= n; j++)
        {
            if(i == j)
                e[i][j] = 0;
            else 
                e[i][j] = 99999999;
        }
    }

    int a, b;
    for(i = 1; i <= n; i++)
    {

        scanf("%d %d", &a, &b);
        e[a][b] = 1;
        e[b][a] = 1;
    }

    head = 1;
    tail = 1;

    que[tail] = 1;
    tail++;
    book[1] = 1;

    int cur;
    while(head < tail && tail <= n)
    {
        cur = que[head];
        for(i = 1; i <= n; i++)
        {
            if(e[cur][i] == 1 && book[i] == 0)
            {
                book[i] = 1;
                que[tail] = i;
                tail++;
            }

            if(tail > n)
                break;
        }

        head++;
    }

    for(i = 1; i < tail; i++)
        printf("%d ", que[i]);


    return 0;
}

输入样例：
5
1 2
1 3
1 5
2 4
3 5

输出：
1 2 3 5 4