Binary Tree Level Order Traversal II, is a LeetCode problem from Tree subdomain. In this post we will see how we can solve this challenge in Swift

Problem Description

You can find the full details of the problem Binary Tree Level Order Traversal II at LeetCode

Solution

Note: use method insertAtIndex to add each level to final result

Time Complexity: O(n), Space Complexity: O(n)

Definition for a binary tree node.

public class TreeNode {

public var val: Int

public var left: TreeNode?

public var right: TreeNode?

public init(_ val: Int) {

    self.val = val

    self.left = nil

    self.right = nil

}

}

Please check the main.swift snippet for the solution.

This solution originally posted at: Github by @soapyigu