bfs 邻接表（需要优化 可能会RE *【模板】）

//---基于邻接表的bfs


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

using namespace std; 

struct node
{
    int date;
    struct node *next;
}*head[101], *tail[101]; 

void bfs(int s)
{
    int flag=0; //标记输出，保证输出格式的正确的 

    bool vis[101];
    memset(vis, false, sizeof(vis) );
    queue<int>q;    

    vis[s]=true; //标记起点访问
    q.push(s);
    int cur; 

    struct node *p;
    while( !q.empty() )
    {
        cur=q.front();
        if(flag==0)
        {
            printf("%d", cur );
            flag=1;
        }
        else if(flag==1)
        {
            printf(" %d", cur );
        } 

        q.pop();
        if( head[cur] ) //如果不空
        {
            //开始遍历
            p=head[cur]->next;
            while(p)
            {
                if(vis[p->date]==false)
                {
                    q.push(p->date);
                    vis[p->date]=true;
                }
                p=p->next;
            }
        }
    }
    printf("\n");
} 

int main()
{
    int t;
    cin>>t;
    int n, m, s;
    int u, v;
    int i; 

    while(t--)
    {
        for(i=0; i<=100; i++)
        {
            head[i]=new struct node;
            head[i]->next = NULL;
            tail[i] = head[i];
        }
        //邻接表的初始化 

        scanf("%d %d %d", &n, &m, &s) ;
        struct node *p, *q;
        for(i=0; i<m; i++)
        {
            scanf("%d %d", &u, &v );
            p=new struct node;
            p->date=v; p->next=NULL;
            q=new struct node;
            q->date=u; q->next=NULL; 

            tail[u]->next=p;  tail[u]=p;
            tail[v]->next=q;  tail[v]=q;
        }  //建立邻接表
        bfs(s);
    }
    return 0;
}