//表示节点的数据结构struct node{    int val;    node *lch,*rch;};//插入数值node *insert(node *p,int x){    if(p==NULL)    {        node *q=new node;        q->val=x;        q->lch=q->rch=NULL;        return q;    }    else    {        if(x<p->val) p->lch=insert(p->lch,x);        else p->rch=insert(p->rch,x);        return p;    }}//查找数值bool find(node *p,int x){    if(p==NULL) return false;    else if(x==p->val) return true;    else if(x<p->val) return find(p->lch,x);    else if(x>p->val) return find(p->rch,x);}//删除数值node *remove(node *p,int x){    if(p==NULL) return NULL;    else if(x<p->val) p->lch=remove(p->lch,x);    else if(x>p->val) p->rch=remove(p->rch,x);    else if(p->lch==NULL)    {        node *q=p->rch;        delete p;        return q;    }    else if(p->lch->rch==NULL)    {        node *q=p->lch;        q->rch=p->rch;        delete p;        return q;    }    else    {        node *q;        for(q=p->lch;q->rch->rch!=NULL;q=q->rch);        node *r=q->rch;        q->rch=r->lch;        r->lch=p->lch;        r->rch=p->rch;        delete p;        return r;    }    return p;}