LeetCode110 Balanced Binary Tree

Given a binary tree, determine if it is height-balanced.

For this problem, a height-balanced binary tree is defined as a binary tree in which the depth of the two subtrees of every node never differ by more than 1.（Easy）

分析：

利用辅助函数求深度，然后根据heighted-balanced定义判定即可

代码：

class Solution {
    int depth(TreeNode* root) {
        if (root == nullptr) {
            return 0;
        }
        return max(depth(root -> left), depth(root -> right)) + 1;
    }
public:
    bool isBalanced(TreeNode* root) {
        if (root == nullptr) {
            return true;
        }
        int left = depth(root -> left);
        int right = depth(root -> right);
        if (abs(left - right) <= 1 && isBalanced(root -> left) && isBalanced(root -> right)) {
            return true;
        }
        return false;
    }
};