leetcode-----110. 平衡二叉树

• 链接：https://leetcode-cn.com/problems/balanced-binary-tree/

代码

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */
class Solution {
public:
    bool ans;
    bool isBalanced(TreeNode* root) {
        ans = true;
        dfs(root);
        return ans;
    }

    int dfs(TreeNode* root) {
        if (!root) return 0;
        int lh = dfs(root->left), rh = dfs(root->right);
        if (abs(lh - rh) > 1) ans = false;
        return max(lh, rh) + 1;
    }
};