Tag: leetcode

We have talked about the Pre-order in this post, and In-order Traversal for binary tree in this post. And this article talks about the third kind: Postorder traversal, which …

Return the preorder traversal of a binary tree’s nodes’ values. The pre-order displays the root/current node’s value first, then recursively calling into its left sub tree and right sub …

Reverse a linked list from position m to n. For example: Given 1-2-3-4-5-NULL, m = 2 and n = 4, return 1-4-3-2-5-NULL. 1 ≤ m ≤ n ≤ length …

Remove the nth node from the end of a singly linked list and return its head. For example, input: 1-2-3-4-5, and n = 2. Removing the second node from …

Write a function to reverse only the vowels of a string. Example: Given s = “hello”, return “holle”. A vowel is one of the following 10 letters (both uppercase …