剑指Offer - 平衡二叉树

class Solution {
    bool isBalance(TreeNode* pRoot, int &h) {
        if (!pRoot) {
            h = 0;
            return true;
        }
        int lh, rh;
        if (!isBalance(pRoot->left, lh) ||
            !isBalance(pRoot->right, rh)) return false;
        
        if (lh > rh + 1 || rh > lh + 1) return false;
        h = lh > rh ? lh + 1 : rh + 1;
        
        return true;
    }
public:
    bool IsBalanced_Solution(TreeNode* pRoot) {
        int h = 0;
        return isBalance(pRoot, h);
    }
};