图的存储

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

int k,h[110],mark;

struct M
{
    int data;
    struct M *next;
}*head[110];

void init()
{
    int i;
    for(i = 0; i < k; i++)
    {
        head[i] = (struct M *)malloc(sizeof(struct M));
        head[i]->next = NULL;
        head[i]->data = -1;
    }
}

void link(int u,int v)
{
    struct M *p1,*p2,*q;
    q = (struct M *)malloc(sizeof(struct M));
    q->next = NULL;
    q->data = v;
    for(p1 = head[u],p2 = p1->next; p2 != NULL; p1 = p1->next,p2 = p2->next)
    {
        if(p1->data < v && p2->data > v)
        {
            q->next = p1->next;
            p1->next = q;
            return;
        }
        else if(p2->data == v)
        {
            free(q);
            return;
        }
    }
    p1->next = q;
}

void seek(int mb)
{
    struct M *p;
    int q[105],s,e;
    s = e = 0;
    q[e++] = mb;
    while(s < e)
    {
        mb = q[s++];
        if(mark)
        {
            mark = 0;
            printf("%d",mb);
        }
        else printf(" %d",mb);
        for(p = head[mb]->next; p != NULL; p = p->next)
        {
            if(!h[p->data])
            {
                h[p->data] = 1;
                q[e++] = p->data;
            }
        }
    }
}

int main()
{
    int js,m,t,i,u,v;
    struct M *p;
    scanf("%d",&js);
    while(js--)
    {
        scanf("%d %d %d",&k,&m,&t);
        init();
        for(i = 0; i < m; i++)
        {
            scanf("%d %d",&u,&v);
            link(u,v);
            link(v,u);
        }
        memset(h,0,sizeof(h));
        h[t] = 1;
        mark = 1;
        seek(t);
        printf("\n");
    }
    return 0;
}