【前端】自学基础算法 -- 17.平横二叉树

平衡二叉树

示例方法

class Node {
  constructor(value) {
    this.value = value
    this.left = null
    this.right = null
  }
}

let a = new Node('a')
let b = new Node('b')
let c = new Node('c')
let d = new Node('d')
let e = new Node('e')
let f = new Node('f')
let g = new Node('g')
let h = new Node('h')
let i = new Node('i')

a.left = b
a.right = c
b.left = d
b.right = e
c.left = f
c.right = g
d.left = h
e.right = i // true
// h.left = i // false

// 获取二叉树的深度
function getDeep(root) {
  if (root === null) return 0
  let leftDeep = getDeep(root.left)
  let rightDeep = getDeep(root.right)
  return Math.max(leftDeep, rightDeep) + 1
}

function isBalanced(root) {
  if (root === null) return true
  let leftDeep = getDeep(root.left)
  let rightDeep = getDeep(root.right)
  // 如果左右子树的高度差大于1，则不是平衡二叉树
  if (Math.abs(leftDeep - rightDeep) > 1) return false
  // 如果左右子树的高度差小于等于1，则继续判断左右子树是否是平衡二叉树
  return isBalanced(root.left) && isBalanced(root.right)
}

console.log(isBalanced(a))