binaryTree:普通二叉树

#ifndef _Tree_H
#define _Tree_H
typedef int ElementType;

typedef struct TreeNode
{
    ElementType Element;
    struct TreeNode *Left;
    struct TreeNode *Right;
}*Position, *SearchTree;

SearchTree MakeEmpty(SearchTree T);
Position Find(ElementType X, SearchTree T);
Position FindMin(SearchTree T);
Position FindMax(SearchTree T);
SearchTree Insert(ElementType X, SearchTree T);
SearchTree Delete(ElementType X, SearchTree T);

#endif

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

SearchTree MakeEmpty(SearchTree T)
{
    if (T != NULL)
    {
        MakeEmpty(T->Left);
        MakeEmpty(T->Right);
        free(T);
    }
    return NULL;
}

Position Find(ElementType X, SearchTree T)
{
    if (T == NULL)
        return NULL;
    else if (X < T->Element)
        return Find(X, T->Left);
    else if (X > T->Element)
        return Find(X, T->Right);    //都需要return
    else 
        return T;
    
}

Position FindMin(SearchTree T)
{
    if (T == NULL)
    {
        return NULL;
    }
    else if (T->Left == NULL)
    {
        return T;
    }
    else 
    {
        return FindMin(T->Left);
    }
}

Position FindMax(SearchTree T)
{
    if (T == NULL)
    {
        while (T->Right != NULL)
        {
            T = T->Right;
        }
    }
    return T;
}
SearchTree Insert(ElementType X, SearchTree T)
{
    if (T == NULL)
    {
        T = malloc(sizeof(struct TreeNode));
        if (T == NULL)
            perror("malloc error\n");
        else
        {
            T->Element = X;
            T->Left = NULL;
            T->Right = NULL;
        }
    }
    else if (X < T->Element)
        T->Left = Insert(X, T->Left);
    else if (X > T->Element)
        T->Right = Insert(X, T->Right);
    return T;
}

SearchTree Delete(ElementType X, SearchTree T)
{
    Position TmpCell = NULL;

    if (T == NULL)
    {
        printf("Element not found");
    }
    else if (X < T->Element)
    {
        T->Left = Delete(X, T->Left);
    }
    else if (X > T->Element)
    {
        T->Right = Delete(X, T->Right);
    }
    else if (T->Left && T->Right)        //找到值
    {
        TmpCell = FindMin(T->Right);        //找出右子树中的最小值，这样它没有左子树
        T->Element = TmpCell->Element;
        T->Right = Delete(T->Element, T->Right);
    }
    else                //只有左子树或只有右子树
    {
        TmpCell = T;
        if (T->Left == NULL)
        {
            T = T->Right;
        }
        else if (T->Right == NULL)
        {
            T = T->Left;
        }
        free(TmpCell);
    }
    return T;
}


void printMember(Position T)
{
    if (T == NULL)
        printf("this Position is not exit\n");
    else
    printf("Element = %d\n", T->Element);
}

void printTree(SearchTree T, int deep, char *s)
{
    int i = deep;
    if (T == NULL)
        return;
    i++;
    while (deep)
    {
        printf("\t");
        deep--;
    }
    printf("%s -> %d\n",s, T->Element);
    printTree(T->Left, i, "left");
    printTree(T->Right, i, "right");
    return;
}
int main()
{
    SearchTree T = NULL;
    MakeEmpty(T);
    T = Insert(3, T);
    T = Insert(1, T);
    T = Insert(5, T);
    T = Insert(2, T);
    T = Insert(5, T);
    T = Insert(4, T);
    T = Insert(6, T);
    printTree(T, 0,"start");
    printMember(Find(6, T));
    printMember(FindMax(T));
    printMember(FindMin(T));
    T = Delete(3, T);
    printTree(T, 0, "delete");

}