PTA 6-12 二叉搜索树的操作集
本题要求实现给定二叉搜索树的5种常用操作。
函数接口定义：
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 );- 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。
其中BinTree结构定义如下：
typedef struct TNode *Position; typedef Position BinTree; struct TNode{ ElementType Data; BinTree Left; BinTree Right; };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("\n"); 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\n", X); else { printf("%d is found\n", Tmp->Data); if (Tmp==MinP) printf("%d is the smallest key\n", Tmp->Data); if (Tmp==MaxP) printf("%d is the largest key\n", Tmp->Data); } } scanf("%d", &N); for( i=0; i<N; i++ ) { scanf("%d", &X); BST = Delete(BST, X); } printf("Inorder:"); InorderTraversal(BST); printf("\n"); return 0; } /* 你的代码将被嵌在这里 */输入：
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：
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代码：
BinTree Insert( BinTree BST, ElementType X ){ if(BST == NULL){ BST = (BinTree)malloc(sizeof(struct TNode)); BST->Data = X; BST->Left = NULL; BST->Right = NULL; }else if(X<BST->Data){ BST->Left = Insert(BST->Left,X); }else if(X>BST->Data){ BST->Right = Insert(BST->Right,X); } return BST; } BinTree Delete( BinTree BST, ElementType X ){ BinTree temp; if(BST != NULL){ if(X<BST->Data){ BST->Left = Delete(BST->Left,X); }else if(X>BST->Data){ BST->Right = Delete(BST->Right,X); }else{ if(BST->Left&&BST->Right){ temp = FindMin(BST->Right); BST->Data = temp->Data; BST->Right = Delete(BST->Right,temp->Data); }else{ temp = BST; if(BST->Left == NULL) BST = BST->Right; else if(BST->Right == NULL) BST = BST->Left; free(temp); } } return BST; } printf("Not Found\n"); return BST; } Position Find( BinTree BST, ElementType X ){ if(BST==NULL) return NULL; if(BST->Data == X) return BST; if(BST!=NULL){ if(X<BST->Data) return Find(BST->Left,X); else if(X>BST->Data) return Find(BST->Right,X); } } Position FindMin( BinTree BST ){ if(BST){ while(BST->Left){ BST = BST->Left; } } return BST; } Position FindMax( BinTree BST ){ if(BST){ while(BST->Right){ BST = BST->Right; } } return BST; }