Insert and delete binary sorting tree

The following procedure creates, inserts, and deletes a binary sorting tree!

#include<iostream>#include<vector>using namespace std;struct LNode{    int data;    LNode *lchild;    LNode *rchild;};void buildtree(LNode *root,LNode *q){    LNode *p=root;    while(1){        if(q->data==p->data)            break;        else{            if((q->data)>(p->data)){                if(p->rchild!=NULL)                    p=p->rchild;                else{                    p->rchild=q;                    break;                }            }            else{                if(p->lchild!=NULL)                    p=p->lchild;                else{                    p->lchild=q;                    break;                }            }        }    }}void del(LNode *root,LNode *q){    LNode *p=root;    LNode *r;    while(1){        if(p->data==q->data){            if(p->lchild==NULL&&p->rchild==NULL){                if(r->lchild==p)                    r->lchild=NULL;                else                    r->rchild=NULL;                delete p;                break;            }                                        if(p->lchild==NULL&&p->rchild!=NULL){                if(r->lchild==p)                    r->lchild=p->rchild;                else                    r->rchild=p->rchild;                delete p;                break;            }            if(p->lchild!=NULL&&p->rchild==NULL){                if(r->lchild==p)                    r->lchild=p->lchild;                else                    r->rchild=p->lchild;                delete p;                break;            }                                        if(p->lchild!=NULL&&p->rchild!=NULL){                LNode *q;                if(!p->lchild){                    q=p->lchild;                    while(!(q->rchild))                        q=q->rchild;                    p->data=q->data;                    delete q;                    break;                }                else{                    q=p->rchild;                    while(!(q->lchild))                        q=q->lchild;                    p->data=q->data;                    delete q;                    break;                }            }        }        else{            if((p->data)>(q->data)){                r=p;                p=p->lchild;            }            else{                r=p;                p=p->rchild;            }        }    }}void inorder(LNode *root){    if(root){        inorder(root->lchild);        cout<<root->data<<" ";        inorder(root->rchild);    }}int main(){    vector<int> sevc;    int ch;    while(cin>>ch&&ch!=0)        sevc.push_back(ch);          vector<int>::iterator iter;    iter=sevc.begin();    LNode *root=new LNode;    root->data=*iter;    root->lchild=NULL;    root->rchild=NULL;          ++iter;    LNode *p;    for(;iter!=sevc.end();++iter){        p=root;        LNode *q=new LNode;        q->data=*iter;        q->lchild=NULL;        q->rchild=NULL;        buildtree(p,q);    }          p=root;    inorder(p);    cout<<endl;          cin.ignore();    p=root;    cin>>ch;    LNode *q=new LNode;    q->data=ch;    q->lchild=NULL;    q->rchild=NULL;    del(p,q);          p=root;    inorder(p);    cout<<endl;          delete p;    delete q;    delete root;          return 0;}

This article is from the "cainiao's advanced road" blog, please be sure to keep this source http://beyond316.blog.51cto.com/7367775/1266364