//BFS algorithm
int shortestpath(Node *array, int Vnum, int root, int des)
{
int i,out,ss;
//create a queue
Queue *head=Initqueue();
Queue *path=Initqueue();
Node *travel,*p;
int *color = (int *)malloc(Vnum*sizeof(int));
int *father = (int *)malloc(Vnum*sizeof(int));
for(i=0;i<Vnum;i++)father[i]=i;
for(i=0;i<Vnum;i++)color[i]=white; //initialize colar
Enqueue(head,root);
color[root]=grey;
father[root]=root;
while(Isempty(head)!=1)
{
out = Dequeue(head);
travel=array+out;
for(p=travel->next;p!=NULL;p=p->next)
{
if(color[p->ID]==white)
{
Enqueue(head,p->ID);
color[p->ID]=grey;
father[p->ID]=out;
}
}
color[out]=black;
}
if(color[des]==white)
{
printf("Error: there is no path between %d and %d.",root,des);
ss=false;
}
else
{
//if there is a path, then print it out
//for(i=0;i<Vnum;i++)printf("%d is father of %d\n",father[i],i);
PrintPath(father,root,des);
ss=true;
}
Clearqueue(head);
Destroyqueue(head);
free(color);
free(father);
return ss;
}
int main()
{
LinkQueue q;
Initqueue(&q); //取q的地址
EnQueue(&q,'A'); //入队
printf("%c\n",DeQueue(&q)); //出队并返回出队的值
return 0;
}
