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q0543.swift
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q0543.swift
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//
// q0543.swift
// LeetcodeSwift
//
// Created by NowOrNever on 11/04/2020.
// Copyright © 2020 DL. All rights reserved.
//
import Foundation
//543. Diameter of Binary Tree
//Easy
//
//2372
//
//150
//
//Add to List
//
//Share
//Given a binary tree, you need to compute the length of the diameter of the tree. The diameter of a binary tree is the length of the longest path between any two nodes in a tree. This path may or may not pass through the root.
//
//Example:
//Given a binary tree
// 1
// / \
// 2 3
// / \
// 4 5
//Return 3, which is the length of the path [4,2,1,3] or [5,2,1,3].
//
//Note: The length of path between two nodes is represented by the number of edges between them.
//
//Accepted
//229,635
//Submissions
//474,370
class q0543Solution {
var max = 0
func diameterOfBinaryTree(_ root: TreeNode?) -> Int {
_ = maxLength(root)
return max
}
func maxLength(_ root: TreeNode?) -> Int{
guard root != nil else {
return 0
}
let maxLeft = maxLength(root?.left)
let maxRight = maxLength(root?.right)
if maxLeft + maxRight > max {
max = maxLeft + maxRight
}
return (maxLeft > maxRight ? maxLeft : maxRight) + 1
}
}