[剑指offer]二叉树深度vs判断平衡二叉树

/* 39:> 二叉树的深度 */
int Depth(BinTree* pRoot)
{
    if (pRoot == NULL)
        return 0;
    int nLeft = Depth(pRoot->m_pLeft);
    int nRight = Depth(pRoot->m_pRight);

    return (nLeft > nRight) ? (nLeft + 1) : (nRight+1);
}
/* 判断是不是平衡二叉树 （每个节点遍历一遍的解法） 即，遍历当前结点前，其左右子树已经遍历并确定了深度 */

bool IsBalanced(BinTree* pRoot, int *depth);


bool IsBalanced(BinTree* pRoot)
{
    int depth = 0;
    return IsBalanced(pRoot, &depth);
}

bool IsBalanced(BinTree* pRoot, int *depth)
{
    if (pRoot == NULL)
    {
        *depth = 0;
        return true;
    }

    int left = 0;
    int right = 0;

    if (IsBalanced(pRoot->m_pLeft, &left)
        && IsBalanced(pRoot->m_pRight, &right))
    {
        int dif = left - right;
        if (dif <= 1 || dif >= -1)
        {
            *depth = left > right ? (left + 1) : (right+1);
            return true;
        }
    }
    return false;
}