查找树ADT-二叉查找树

/////////////////////////////// tree.h  /////////////////////////////////
#ifndef _TREE_H_
#define _TREE_H_
#define ElementType int

struct TreeNode;
typedef struct TreeNode * Position;
typedef struct TreeNode * SearchTree;

SearchTree	MakeEmpty(SearchTree t);
Position	Find(ElementType x,SearchTree t);
Position	FindMin(SearchTree t);
Position	FindMax(SearchTree t);
Position	Insert(ElementType x,SearchTree t);
Position	Delete(ElementType x,SearchTree t);
ElementType Retrieve(Position p);

#endif

struct TreeNode {
ElementType Element;
SearchTree Left;
SearchTree Right;
};
//////////////////////////////////////////////////////////////////////////
#include "tree.h"
#include <stdio.h>
#include <stdlib.h>

//建立一棵空树的例程
SearchTree MakeEmpty(SearchTree t)
{
if (t != NULL)
{
MakeEmpty(t->Left);
MakeEmpty(t->Right);
free(t);
}
return NULL;
}
//先序遍历
void Preorder_TreePrint(SearchTree t)
{
if(t!=NULL)
{
printf("%d ",t->Element);
Preorder_TreePrint(t->Left);
Preorder_TreePrint(t->Right);
}
}
//中序遍历
void Inorder_TreePrint(SearchTree t)
{
if(t!=NULL)
{
Inorder_TreePrint(t->Left);
printf("%d ",t->Element);
Inorder_TreePrint(t->Right);
}
}
//后续遍历
void Postorder_TreePrint(SearchTree t)
{
if(t!=NULL)
{
Postorder_TreePrint(t->Left);
Postorder_TreePrint(t->Right);
printf("%d ",t->Element);
}
}
//查找元素
Position Find(ElementType x,SearchTree t)
{
if (t == NULL)
{
return NULL;
}
if (x < t->Element)
{
return Find(x,t->Left);
}
else if (x > t->Element)
{
return Find(x,t->Right);
}
else
return t;
}

//查找最小值
Position FindMin(SearchTree t)
{
if (t == NULL)
{
return NULL;
}
else if (t->Left == NULL)
{
return t;
}
else
return FindMin(t->Left);
}

//查找最大值
Position FindMax(SearchTree t)
{
if (t != NULL)
{
while (t->Right != NULL)
{
t=t->Right;
}
}
return t;
}

//插入元素
SearchTree Insert(ElementType x,SearchTree t)
{
if (t == NULL)
{
t = (SearchTree)malloc(sizeof(struct TreeNode));
if (t == NULL)
{
printf("Out of space!!/n");
}
else
{
t->Element = x;
t->Left = t->Right = NULL;
}
}
else if (x < t->Element)
{
t->Left = Insert(x,t->Left);
}
else
{
t->Right = Insert(x,t->Right);
}

return t;
}

//删除元素
SearchTree Delete(ElementType x,SearchTree t)
{
Position TmpCell;

if (t == NULL)
{
printf("Element not found!/n");
}
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) {
TmpCell = FindMin(t->Right);
t->Element = TmpCell->Element;
t->Right = Delete(t->Element,t->Right);
}
else
{
TmpCell = t;
if (t->Left == NULL)
{
t = t->Right;
}
else if (t->Right == NULL)
{
t = t->Left;
}
free(TmpCell);
}
return t;
}

//////////////////////////////////////////////////////////////////////////
int main(void)
{
int i = 0;
SearchTree st = NULL;
Position min = NULL;
Position max = NULL;
for(i=0;i<20;i++)
{
st = Insert(i,st);
}
Inorder_TreePrint(st);
min = FindMin(st);
max	= FindMax(st);
printf("min=%d  max=%d/n",min->Element,max->Element);
return 0;
}