二叉搜索樹的常用操作

參考 ：http://blog.csdn.net/wanmeiwushang/article/details/51921821

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

typedef enum {false,true}bool;
typedef int ElementType;
typedef struct TNode* BinTree;
struct TNode{
	ElementType data;
	BinTree Left;
	BinTree Right;
};

BinTree BuildTree();
bool IsBST(BinTree T);
int maxValue(BinTree T);
int minValue(BinTree T);
void PreOrderTraverse(BinTree T);
void InOrderTraverse(BinTree T);
void PostOrderTraverse(BinTree T);

BinTree Insert(BinTree T, ElementType X);
BinTree Delete(BinTree T, ElementType X );
BinTree FindMin( BinTree T );
BinTree FindMax( BinTree T );

BinTree Find( BinTree BST, ElementType X );


int main(){
	BinTree T;

	T=BuildTree();

	if(IsBST(T))
		printf("YES!\n");
	else
		printf("NO!\n");

	printf("PreOrder: ");
	PreOrderTraverse(T);
	printf("\n");
	printf("InOrder: ");
	InOrderTraverse(T);
	printf("\n");
	printf("PostOrder: ");
	PostOrderTraverse(T);
	printf("\n");

	Delete(T, 3);
	Delete(T, 7);
	printf("PreOrder: ");
	PreOrderTraverse(T);
	printf("\n");
	T = Find(T, 5);
	printf("T->data = %d\n", T->data);

	return 0;
}
/* 
 4 3 1 -1 2 -1 -1 -1 5 -1 7 6 -1 -1 8 -1 -1 
 4 
 */  
//PreOrder:  4 3 1 2 5 7 6 8
//InOrder:   1 2 3 4 5 6 7 8
//PostOrder: 2 1 3 6 8 7 5 4


BinTree BuildTree(){
	BinTree T=NULL;
	ElementType val;

	scanf("%d", &val);

	if(val==-1)
		return T;

	T = (BinTree)malloc(sizeof(struct TNode));
	T->data = val;
	T->Left = BuildTree();
	T->Right = BuildTree();
	
	return T;
}

bool IsBST(BinTree T){
	if(T==NULL)
		return true;
	if(T->Left!=NULL&&maxValue(T->Left)>T->data)
		return false;
	if(T->Right!=NULL&&maxValue(T->Right)<=T->data)
		return false;
	return IsBST(T->Left)&&IsBST(T->Right);
}

int maxValue(BinTree T){
	BinTree p;
	int max;

	max=T->data;
	p=T->Left;
	while(p){
		if(max<p->data)
			max=p->data;
		p=p->Left;
	}
	return max;
}


int minValue(BinTree T){
	BinTree p;
	int min;

	min=T->data;
	p=T->Right;

	while(p){
		if(min>p->data)
			min=p->data;
		p=p->Right;
	}

	return min;
}

void PreOrderTraverse(BinTree T){
	if(T==NULL)
		return;
	printf("%d ", T->data);
	PreOrderTraverse(T->Left);
	PreOrderTraverse(T->Right);
}
void InOrderTraverse(BinTree T){
	if(T==NULL)
		return;
	InOrderTraverse(T->Left);
	printf("%d ", T->data);
	InOrderTraverse(T->Right);
}
void PostOrderTraverse(BinTree T){
	if(T==NULL)
		return;
	PostOrderTraverse(T->Left);
	PostOrderTraverse(T->Right);
	printf("%d ", T->data);
}


BinTree Insert(BinTree T, ElementType X){
	if(T==NULL){
		T = (BinTree)malloc(sizeof(struct TNode));
		T->data = X;
		T->Left = NULL;
		T->Right = NULL;
	}
	else{
		if(X<T->data)
			T->Left=Insert(T->Left, X);
		else if(X>T->data)
			T->Right=Insert(T->Right, X);
	}
	return T;
}
BinTree Delete(BinTree T, ElementType X ){
	BinTree tmp;
	if(NULL==T){
		printf("Not Found!\n");
		return T;
	}
	if(X<T->data)
		T->Left=Delete(T->Left, X);
	else if(X>T->data)
		T->Right=Delete(T->Right, X);
	else{
		if(T->Left&&T->Right){
			tmp = FindMin(T->Right);
			T->data=tmp->data;
			T->Right = Delete(T->Right, T->data);		
		}
		else{
			tmp = T;  
           if(T->Left==NULL)  
				T=T->Right;  
           else if(T->Right==NULL)  
				T=T->Left;
            free(tmp);  
		}
	}

	return T;
}
BinTree FindMin( BinTree T ){
	if(T){
		while(T->Left)
			T=T->Left;
	}
	return T;
}
BinTree FindMax( BinTree T ){
	if(T){
		while(T->Right)
			T=T->Right;
	}
	return T;
}

BinTree Find( BinTree T, ElementType X ){
	if(NULL==T)
		return NULL;
	if(X<T->data)
		return Find(T->Left, X);
	else if(X>T->data)
		return Find(T->Right, X);
	else
		return T;
}