二叉查找树的基本实现-c语言

#include<stdio.h>
#include<stdlib.h>
struct BinaryTree;
typedef BinaryTree *position;
typedef position SearchTree;
struct BinaryTree
{
    int Element;
    position Left;
    position right;
};
SearchTree creat(SearchTree t);//构造二叉树
SearchTree MakeEmpty(SearchTree t);//这个函数把二叉树销毁了，空树。
position Find(int x, SearchTree t);//寻找x的节点
position FindMin(SearchTree t);//二叉树的最小节点
position FindMax(SearchTree t);//二叉树的最大节点
SearchTree Insert(int x, SearchTree t);//插入元素，返回树根
SearchTree Delete(int x,SearchTree t);//
int Retrieve(position p);//返回节点元素
void PreOrderTraverse(SearchTree t);//先序遍历
void midprint(SearchTree t);//中序遍历
void traversingprint(SearchTree t);//后序遍历
SearchTree creat(SearchTree t)
{
    int num;
    scanf("%d", &num);
    t = (SearchTree)malloc(sizeof(struct BinaryTree));
    if (t == NULL)
    {
        printf("No space!\n");
        return NULL;
    }
    t->Element = num;
    t->Left = NULL;
    t->right = NULL;
    return t;
}
SearchTree MakeEmpty(SearchTree t)
{
    if (t != NULL)
    {
        MakeEmpty(t->Left);
        MakeEmpty(t->right);
        free(t);
    }
    return NULL;
}
position Find(int x, SearchTree t)
{
    if (t == NULL)
        return NULL;
    if (t->Element == x)
        return t;
    else if (x < t->Element)
        return Find(x, t->Left);
    else
        return Find(x, t->right);
}
position FindMin(SearchTree t)
{
    if (t == NULL)
        return t;
    else if (t->Left == NULL)
        return t;
    else
        return FindMin(t->Left);
}
position FindMax(SearchTree t)
{
    if (t == NULL)
        return NULL;
    else if (t->right == NULL)
        return t;
    else
        return FindMax(t->right);
}
SearchTree Insert(int x, SearchTree t)
{
    if (t == NULL)
    {
        t = (SearchTree)malloc(sizeof(struct BinaryTree));
        if (t == NULL)
        {
            printf("No space\n");
            return NULL;
        }
        t->Element = x;
        t->Left = 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(int x,SearchTree t)
{
    if (t == NULL)
        return NULL;
    else if (x < t->Element)            //小于t，递归查找
        t->Left = Delete(x, t->Left);
    else if (x > t->Element)
        t->right = Delete(x, t->right);
    else if (t->Left&&t->right)    //等于t，左右儿子齐全
    {
        position p;
        p = FindMin(t->right);               //找到右子树的最小值，赋给t，然后再删除被复制的节点，确保只有一个。
        t->Element = p->Element;
        t->right = Delete(t->Element, t->right);
    }
    else        //等于t，只有一个儿子或者没有儿子
    {
        position p;
        p = t;
        if (t->Left == NULL)           //找个儿子接班，没有就置空。
            t = t->right;
        else if (t->right == NULL)
            t = t->Left;
        free(p);
    }
    return t;
}
int Retrieve(position p)
{
    return p->Element;
}
void PreOrderTraverse(SearchTree t)
{
    if (t)
    {
        printf("%d\n", t->Element);
        PreOrderTraverse(t->Left);
        PreOrderTraverse(t->right);
    }
}
void midprint(SearchTree t)
{
    if (t)
    {
        midprint(t->Left);
        printf("%d\n", t->Element);
        midprint(t->right);
    }
}
void traversingprint(SearchTree t)
{
    if (t)
    {
        traversingprint(t->Left);
        traversingprint(t->right);
        printf("%d\n", t->Element);
    }
}

测试一下

#include<stdio.h>
#include"BinaryTree.h"
int main()
{
    SearchTree t=NULL;
    t = creat(t);
    int n,num;
    scanf("%d", &n);
    while (n--)
    {
        scanf("%d", &num);
        Insert(num, t);
    }
    position p;
    p = FindMin(t);
    printf("最小值是%d\n", p->Element);
    p = FindMax(t);
    printf("最大的值是%d\n", p->Element);
    printf("先序遍历：\n");
    PreOrderTraverse(t);
    printf("中序遍历:\n");
    midprint(t);
    return 0;
}