struct node

{

    int data;

    int height;

    node *lc;

    node *rc;

    node()

        : data(0)

        , height(0)

        , lc(0)

        , rc(0)

    {

    }

};

// 判断是否为平衡二叉树,若是，则返回树的高度

    // false - 不是平衡二叉树，true-是平衡二叉树

    bool is_avl_tree(node *pnode, int &deepth)

    {

        if ( NULL == pnode)

        {

            deepth = 0;

            return true;

        }

        int left_h = 0;

        int right_h = 0;

        if (is_avl_tree(pnode->lc, left_h) && is_avl_tree(pnode->rc, right_h))

        {

            int diff = abs(left_h - right_h);

            if (1 < diff)

                return false;

            deepth = 1 + ( (left_h > right_h) ? left_h : right_h);

            return true;

        }

        return false;

    }