#include<stdio.h>
#include<malloc.h>
typedef int Element;
typedef struct trees *Pointer;
typedef struct trees {
	Element data;
	Pointer Left;
	Pointer Right;
}Tree;
typedef Tree *BinTree;
BinTree createTree() 
{
	Tree *T = NULL;
	return T;
}
BinTree TreeInsert(BinTree T, int x)
{
	if (T == NULL)
	{
		T = (BinTree)malloc(sizeof(Tree));
		if (T == NULL)
			return NULL;
		T->data = x;
		T->Left = T->Right = NULL;
	}
	else
	{
		if (T->data > x)
			T->Left = TreeInsert(T->Left, x);


		else if (x > T->data)
			T->Right = TreeInsert(T->Right, x);
	}


	return T;
}
BinTree FindMin(BinTree BT)
{
	if (!BT)//空树
		return BT;
	else if (!BT->Left)
		return BT;//在结点的左子树寻找最小值
	else
		FindMin(BT->Left);
}
BinTree FindMax(BinTree T)
{
	Pointer B = T;
	if (T)
	{
		while (B->Right)
			B = B->Right;
	}
	return B;
}
BinTree Delete(Pointer T, Element X)
{
	if (!T)
		printf("the tree is null!\n");
	else
	{
		if (X < T->data)
			T->Left = Delete(T->Left, X);
		else if (X > T->data)
			T->Right = Delete(T->Right, X);
		else//删除选择
		{
			//待删除结点有左右两个子树
			if (T->Left && T->Right)
			{//右子树中寻找最小值，替代结点
				Pointer tmp = FindMin(T->Right);
				T->data = tmp->data;//替代
				//从右子树中删除tmp结点
				T->Right = Delete(T->Right, tmp->data);
			}
			else//待删除结点只有一个子节点或者没有子结点
			{
				BinTree tmp = T;
				if (!T->Left)//没有左结点
					T = T->Right;
				else
					T = T->Left;
				free(tmp);
				tmp = NULL;
			}
		}
	}
	return T;
}
void print(BinTree BT)
{
	BinTree queue[100] = { NULL };
	if (BT == NULL)
		printf("空树！\n");
	else
	{
		int tail = 0, front = 0;
		queue[tail++] = BT;
		Pointer T = NULL;
		while (tail != front) {
			T = queue[front++];
			printf("%d\n", T->data);
			if (T->Left)
				queue[tail++] = T->Left;
			if (T->Right)
				queue[tail++] = T->Right;
		}
	}
}
int main(void)
{
	Pointer T = NULL;
	T = createTree();
	int data = 0;
	printf("输入树节点的值！\n输入 0 时输入结束!\n");
	scanf("%d", &data);
	while (data) {
		T = TreeInsert(T, data);
		scanf("%d", &data);
	}
	printf("最大值为：%d\n", FindMax(T)->data);
	print(T);
	printf("请输入一个要删除的结点的值!\n");
	scanf("%d", &data);
	Delete(T, data);
	print(T);


	return 0;
}