下面代码是自己在学习二叉查找树时写的，纯属为了记录自己的学习过程。

//C语言实现二叉查找树 

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

/* run this program using the console pauser or add your own getch, system("pause") or input loop */

typedef struct _SearchTreeNode{
	struct _SearchTreeNode *left;
	struct _SearchTreeNode *right;
	int data;
}SearchTreeNode;

//往二叉查找树中插入元素 
SearchTreeNode *Insert(SearchTreeNode *tree,int element){
	if(tree==NULL){
		tree=(SearchTreeNode*)malloc(sizeof(SearchTreeNode));
		if(tree==NULL){
			printf("error!");
			return NULL;
		}
		else{
			tree->data=element;
			tree->left=tree->right=NULL;
		}
	}
	else{
		if(element<tree->data){
			tree->left=Insert(tree->left,element);
		}
		else{
			tree->right=Insert(tree->right,element);
		}
	}
	return tree;
}

//查找最小值 
SearchTreeNode *FindMin(SearchTreeNode *tree){
	if(tree==NULL){
		return NULL;
	}
	else{
		if(tree->left!=NULL){
			return FindMin(tree->left);
		}
		else{
			return tree;
		}
	}
}

//查找最大值 
SearchTreeNode *FindMax(SearchTreeNode *tree){
	if(tree==NULL){
		return NULL;
	}
	else{
		if(tree->right==NULL){
			return tree;
		}
		else{
			return FindMax(tree->right);
		}
	}
}

//删除二叉查找树中某一元素element 
//分以下几种情况： 
// (1)删除的结点有两个孩子
//（2）删除的结点有一个孩子
//（3）删除的结点没有孩子 
SearchTreeNode *Delete(SearchTreeNode *tree,int element){
	SearchTreeNode *min_right;
	if(tree==NULL){
		return NULL;
	}
	else{
		if(element==tree->data){
			if(tree->right==NULL&&tree->left==NULL){
				tree=NULL;
				return tree;
			}
			else if(tree->right!=NULL&&tree->left==NULL){
				tree=tree->right;
			}
			else if(tree->left!=NULL&&tree->right==NULL){
				tree=tree->left;
			}
			else{
				min_right=FindMin(tree->right);
				tree->data=min_right->data;
				tree->right=Delete(tree->right,tree->data);
			}
		} 
		else if(element<tree->data){
			tree->left=Delete(tree->left,element);
		}
		else{
			tree->right=Delete(tree->right,element);
		}
	}
	return tree;
} 

//查找二叉查找树中的某一元素 
SearchTreeNode *Find(SearchTreeNode *tree,int element){
	if(tree==NULL){
		return NULL;
	}
	else{
		if(element==tree->data){
			return tree;
		}
		else if(element<tree->data){
			return Find(tree->left,element);
		}
		else{
			return Find(tree->right,element);
		}
	}
} 

//先序遍历 
void PreOrder(SearchTreeNode *tree){
	if(tree!=NULL){
		printf(" %d ",tree->data);
		PreOrder(tree->left);
		PreOrder(tree->right); 
	} 
} 

//中序遍历 
void InOrder(SearchTreeNode *tree){
	if(tree!=NULL){
		InOrder(tree->left);
		printf(" %d ",tree->data);
		InOrder(tree->right);
	}
}

int main(int argc, char *argv[]) {
	SearchTreeNode *tree=NULL,*min,*max,*ele;
	tree=Insert(tree,6); 
	tree=Insert(tree,2); 
	tree=Insert(tree,1); 
	tree=Insert(tree,5); 
	tree=Insert(tree,3); 
	tree=Insert(tree,4); 
	tree=Insert(tree,8); 
	tree=Delete(tree,6);
	PreOrder(tree);
	printf("\n");
	InOrder(tree);
	printf("\n");
	min=FindMin(tree);
	printf("the min data of tree is : %d\n",min->data);
	max=FindMax(tree);
	printf("the max data of tree is: %d\n",max->data); 
	ele=Find(tree,1);
	printf("%d",ele->data);
	return 0;
}