ツリーの幅を求める

ツリーの幅を求めるアルゴリズム

void width(Tree T)              //      
{
	int w = 0, wmax = 1, last = -1;
	Tree p;
	queue q;
	q.front = q.rear = -1;
	if(T == NULL)
		printf("       0!
");
	else
	{
		q.data[++q.rear] = T;
		last = q.rear;
		while(q.front < q.rear)
		{
			p = q.data[++q.front];
			if(p->lchild != NULL)
				q.data[++q.rear] = p->lchild;
			if(p->rchild != NULL)
				q.data[++q.rear] = p->rchild;
			w++;
			if(q.front == last)
			{
				if(w > wmax)
					wmax = w;
				w = 0;
				last = q.rear;
			}
		}
		printf("       %d!
", wmax);
	}
}