二叉排序树的插入、删除操作(递推方式)

/*------------tree insert use loop search-----------------------------*/
void insert_tree_loop(PTree _root, int value)
{
        while(NULL !=_root)
        {
            if(value == _root->data)
            {
                return;   
            }   
            else if(value < _root->data)
            {
                if(NULL == _root->lchild)//find node insert new node
                {
                    _root->lchild = create_node(value);//link now node left child node to new node
                }
                else//left tree is not null
                {
                    _root = _root->lchild;
                }
            }
            else
            {
                if(NULL == _root->rchild)//find node inset new node
                {
                    _root->rchild = create_node(value);//link now node right child node to new node
                }
                else//right child tree is not null
                {
                    _root = _root->rchild;   
                }
            }
        }
}

/*-------------------------------------------------------------------------------------------------*/

void delete_tree_loop(PTree _root, int value)
{
    PTree parent=_root;
    PTree temp = NULL;
    if(_root==NULL || value==_root->data)
    {
        return;   
    }   
    while(_root)
    {
            if(value == _root->data)
            {
                break;   
            }
            parent = _root;
            if(value < root->data)
            {
                _root = _root->lchild;   
            }
            else
            {
                _root = _root->rchild;   
            }
    }
    if(_root == NULL)
    {
        return;   
    }//can't find delete node
    else
    {
        if(NULL == _root->lchild)
        {
            if(parent->lchild == _root)//注意条件
            {
                temp =_root;
                parent->lchild = _root->rchild;
                free(temp);
            }
            else
            {
                temp = _root;
                parent->rchild = _root->rchild;
                free(temp);
            }           
        }//left child tree is non,or neither
        else if(NULL == _root->rchild)
        {
            if(parent->lchild == _root)
            {
                temp = _root;
                parent->lchild = _root->lchild;
                free(temp);
            }
            else
            {
                temp = _root;
                parent->rchild = _root->lchild;
                free(temp);
            }
        }//right child tree is non,or neither
        else
        {
            parent = _root;
            temp = _root->lchild;
            while(temp)
            {
                parent = temp;
                temp = temp->rchild;   
            }
            _root->data = temp->data;
            if(parent == _root)
            {
                parent->lchild = temp->lchild;   
            }
            else
            {
                parent->rchild = temp->lchild;
            }
            free(temp);
        }
    }
}