二叉排序树算法，实现查、插、删、改，以及中序遍历

#include "stdio.h"
#include "stdlib.h"
#define N 5
typedef struct BSTnode
{
int key;
struct BSTnode *lchild,*rchild;
}BSTnode,*BSTree;
bool SearchBST(BSTree T,int key,BSTree f,BSTree &p)
{
if (!T)
{
p=f;
return false;
}
else if (key==T->key)
{
p=T;
return true;
}
else if (key<T->key)
{
return SearchBST(T->lchild,key,T,p);
}
else
return SearchBST(T->rchild,key,T,p);
}
bool InsertBST(BSTree &T,int e)
{
BSTnode* s,*p;
if (!SearchBST(T,e,NULL,p))
{
s=(BSTnode*)malloc(sizeof(BSTnode));
s->key=e;
s->lchild=NULL;
s->rchild=NULL;
if (!p)
{
T=s;
}
else if (e<p->key)
{
p->lchild=s;
}
else
p->rchild=s;
return true;
}
else
return false;
}

bool Delete(BSTree &p)
{
BSTnode* q,*s;
if (!p->rchild)
{
q=p;
p=p->lchild;
free(q);
}
else if (!p->lchild)
{
q=p;
p=p->rchild;
free(q);
}
else
{
q=p;
s=p->lchild;
while (s->rchild)
{
q=s;
s=s->rchild;
}
p->key=s->key;
if (q!=p)
{
q->lchild=s->lchild;
}
else
q->lchild=s->lchild;
free(s);
}
return true;
}

bool DeleteBST(BSTree &T,int key)
{
if (!T)
{
return false;
}
else
{
if (key==T->key)
{
return Delete(T);
}
else if (key<T->key)
{
return DeleteBST(T->lchild,key);
}
else return DeleteBST(T->rchild,key);
}
}

void CreateTree(BSTree &root,int data[])
{
BSTree p;
BSTree current;
BSTree father;
int i;
for(i=0;i<N;i++)
{
p=(BSTnode*)malloc(sizeof(BSTnode));
p->key=data[i];
p->lchild=NULL;
p->rchild=NULL;
if (root==NULL)
{
root=p;
}
else
{
current=root;
while (current!=NULL)
{
father=current;
if (current->key>data[i])
{
current=current->lchild;
}
else
current=current->rchild;
}
if (father->key>data[i])
{
father->lchild=p;
}
else
father->rchild=p;
}

}
}
void InOrderBSTree(BSTree T)
{
if (!T)
{
return;
}
else
{
InOrderBSTree(T->lchild);
printf("%d ",T->key);
InOrderBSTree(T->rchild);
}
}
void main()
{
BSTree root=NULL;
BSTree p;
int data
;
int key;
printf("input the data of the tree:/n");
for(int i=0;i<N;i++)
{
scanf("%d",&data[i]);
}
CreateTree(root,data);
InOrderBSTree(root);
printf("/n");

printf("input the key value to search:/n");
scanf("%d",&key);
if (SearchBST(root,key,NULL,p))
{
printf("fouded!/n");
}
else
printf("Not found!/n");

printf("input the key value to insert:/n");
scanf("%d",&key);
InsertBST(root,key);
InOrderBSTree(root);
printf("/n");

printf("input the key value to delete:/n");
scanf("%d",&key);
DeleteBST(root,key);
InOrderBSTree(root);
printf("/n");

}