2022年4月19日（110. 平衡二叉树）

首发于 语雀@blueju

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

2022年4月19日

/**
 * Definition for a binary tree node.
 * function TreeNode(val, left, right) {
 *     this.val = (val===undefined ? 0 : val)
 *     this.left = (left===undefined ? null : left)
 *     this.right = (right===undefined ? null : right)
 * }
 */
/**
 * @param {TreeNode} root
 * @return {boolean}
 */
var isBalanced = function (root) {
    let balance = true
    function traverse(root) {
        if (root === null)
            return 0
        // if (balance === false)
        //     return -800
        let leftMaxHeight = traverse(root.left)
        let rightMaxHeight = traverse(root.right)
        if (Math.abs(rightMaxHeight - leftMaxHeight) > 1) {
            balance = false;
        }
        let xiangcha = Math.max(leftMaxHeight, rightMaxHeight)
        return xiangcha + 1
    }
    traverse(root)
    return balance
};

2022年4月20日
耗时10分钟

/**
 * Definition for a binary tree node.
 * function TreeNode(val, left, right) {
 *     this.val = (val===undefined ? 0 : val)
 *     this.left = (left===undefined ? null : left)
 *     this.right = (right===undefined ? null : right)
 * }
 */
/**
 * @param {TreeNode} root
 * @return {boolean}
 */
var isBalanced = function (root) {
    function traverse(root) {
        if (root === null)
            return 0
        let leftHeight = traverse(root.left)
        let rightHeight = traverse(root.right)
        if (Math.abs(leftHeight - rightHeight) > 1) {
            balance = false
        }
        return 1 + Math.max(leftHeight, rightHeight)
    }
    if (root === null)
        return true
    let balance = true
    traverse(root)
    return balance
};