8.3树表的查找

二叉排序树上的删除

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

typedef int KeyType;//关键字
typedef int DataType;//其他数据域

struct node
{
    KeyType key;//关键字
    DataType other;//其他数据域
    struct node *lchild, *rchild;//左右子树指针
};
typedef struct node BSTNode;//结点类型

BSTNode *Deletebst(BSTNode *T, KeyType x);//查找需要删除的结点
BSTNode *Delete(BSTNode *T);//删除结点

void main()
{

}

BSTNode *Deletebst(BSTNode *T, KeyType x)//查找需要删除的结点
{
    if (!T)//找不到
    {
        return NULL;
    }
    else
    {
        if (T->key == x)
        {
            return Delete(T);
        }
        else if (T->key > x)
        {
            return Deletebst(T->lchild, x);
        }
        else
        {
            return Deletebst(T->rchild, x);
        }
    }
}

BSTNode *Delete(BSTNode *T)//删除结点
{
    BSTNode *q, *s;

    if (T->rchild == NULL)
    {
        q = T;
        T = T->lchild;
        free(q);
    }
    else if (T->lchild == NULL)
    {
        {
            q = T;
            T = T->rchild;
            free(q);
        }
    }
    else
    {
        q = T;
        s = T->lchild;
        while (s->rchild)
        {
            q = s;
            s = s->rchild;
        }
        T->key = s->key;

        if (q != T)
        {
            q->rchild = s->lchild;
        }
        else
        {
            q->lchild = s->lchild;
        }

        free(s);
    }

    return T;
}