题解 | #判断是不是平衡二叉树#

package main

import . "nc_tools"
import "math"

/*
 * type TreeNode struct {
 *   Val int
 *   Left *TreeNode
 *   Right *TreeNode
 * }
 */

/**
 * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
 *
 *
 * @param pRoot TreeNode类
 * @return bool布尔型
 */

func IsBalanced_Solution(pRoot *TreeNode) bool {
	// write code here
	if pRoot == nil {
		return true
	}

	leftDeep := calculateDeepth(pRoot.Left)
	rightDeep := calculateDeepth(pRoot.Right)
	if math.Abs(float64(leftDeep-rightDeep)) > 1 {
		return false
	}
	return IsBalanced_Solution(pRoot.Left) && IsBalanced_Solution(pRoot.Right)
}

func calculateDeepth(node *TreeNode) int {
	if node == nil {
		return 0
	}
	return max(calculateDeepth(node.Right), calculateDeepth(node.Left)) + 1
}

func max(left, right int) int {
	if left > right {
		return left
	}
	return right
}