二叉搜索树的操作集

Posted 2020-12-14 tangyjhappen

函数接口定义：

函数Insert将X插入二叉搜索树BST并返回结果树的根结点指针；
函数Delete将X从二叉搜索树BST中删除，并返回结果树的根结点指针；如果X不在树中，则打印一行Not Found并返回原树的根结点指针；
函数Find在二叉搜索树BST中找到X，返回该结点的指针；如果找不到则返回空指针；
函数FindMin返回二叉搜索树BST中最小元结点的指针；
函数FindMax返回二叉搜索树BST中最大元结点的指针。

裁判测试程序样例

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

typedef int ElementType;
typedef struct TNode *Position;
typedef Position BinTree;
struct TNode{
    ElementType Data;
    BinTree Left;
    BinTree Right;
};

void PreorderTraversal( BinTree BT ); /* 先序遍历，由裁判实现，细节不表 */
void InorderTraversal( BinTree BT );  /* 中序遍历，由裁判实现，细节不表 */

BinTree Insert( BinTree BST, ElementType X );
BinTree Delete( BinTree BST, ElementType X );
Position Find( BinTree BST, ElementType X );
Position FindMin( BinTree BST );
Position FindMax( BinTree BST );

int main()
{
    BinTree BST, MinP, MaxP, Tmp;
    ElementType X;
    int N, i;

    BST = NULL;
    scanf("%d", &N);
    for ( i=0; i<N; i++ ) {
        scanf("%d", &X);
        BST = Insert(BST, X);
    }
    printf("Preorder:"); PreorderTraversal(BST); printf("
");
    MinP = FindMin(BST);
    MaxP = FindMax(BST);
    scanf("%d", &N);
    for( i=0; i<N; i++ ) {
        scanf("%d", &X);
        Tmp = Find(BST, X);
        if (Tmp == NULL) printf("%d is not found
", X);
        else {
            printf("%d is found
", Tmp->Data);
            if (Tmp==MinP) printf("%d is the smallest key
", Tmp->Data);
            if (Tmp==MaxP) printf("%d is the largest key
", Tmp->Data);
        }
    }
    scanf("%d", &N);
    for( i=0; i<N; i++ ) {
        scanf("%d", &X);
        BST = Delete(BST, X);
    }
    printf("Inorder:"); InorderTraversal(BST); printf("
");

    return 0;
}
/* 你的代码将被嵌在这里 */

输入样例：

10
5 8 6 2 4 1 0 10 9 7
5
6 3 10 0 5
5
5 7 0 10 3

输出样例：

Preorder: 5 2 1 0 4 8 6 7 10 9
6 is found
3 is not found
10 is found
10 is the largest key
0 is found
0 is the smallest key
5 is found
Not Found
Inorder: 1 2 4 6 8 9

我的代码

BinTree Insert(BinTree BST, ElementType X) {
	if (!BST) {
		BST = (struct TNode *)malloc(sizeof(struct TNode));
		BST->Data = X;
		BST->Left = BST->Right = NULL;
	}
	else {
		if (X > BST->Data)  BST->Right = Insert(BST->Right, X);
		else if (X < BST->Data)  BST->Left = Insert(BST->Left, X);
	}	
	return BST;
}
Position Find(BinTree BST, ElementType X) {
	BinTree tmp = BST;
	while (tmp) {
		if (X > tmp->Data) tmp = tmp->Right;
		else if (X < tmp->Data) tmp = tmp->Left;
		else  return tmp;
	}
	return NULL;
}
Position FindMin(BinTree BST) {
	BinTree tmp = BST;
	if (!tmp) return NULL;
	while (tmp->Left) {
		tmp = tmp->Left;
	}
	return tmp;
}
Position FindMax(BinTree BST) {
	BinTree tmp = BST;
	if (!tmp) return NULL;
	while (tmp->Right) {
		tmp = tmp->Right;
	}
	return tmp;
}
BinTree Delete(BinTree BST, ElementType X) {
	Position tmp;
	if (!BST) {
		printf("Not Found
");
	}else {
		if (X > BST->Data) BST->Right = Delete(BST->Right, X);
		else if (X < BST->Data) BST->Left = Delete(BST->Left, X);
		else {
			if (BST->Left&&BST->Right) {
				tmp = FindMin(BST->Right);
				BST->Data = tmp->Data;
				BST->Right = Delete(BST->Right, tmp->Data);
			}
			else {
				tmp = BST;
				if (!BST->Left) {
					BST = BST->Right;
				}
				else if (!BST->Right) {
					BST = BST->Left;
				}
				free(tmp);
			}
		}
	}
	return BST;
}