230. Kth Smallest Element in a BST

Given the root of a binary search tree, and an integer k, return the kth smallest value (1-indexed)…

102. Binary Tree Level Order Traversal

Given the root of a binary tree, return the level order traversal of its nodes' values…

371. Sum of Two Integers

Given two integers a and b, return the sum of the two integers without using the operators + and -.

Example 1:

Input: a = 1, b = 2
Output: 3

Example 2:

Input: a = 2, b = 3
Output: 5

105. Construct Binary Tree from Preorder and Inorder Traversal

160. Intersection of Two Linked Lists

Given the heads of two singly linked-lists headA and headB, return the node at which the two…

104. Maximum Depth of Binary Tree

Given the root of a binary tree, return its maximum depth.

141. Linked List Cycle

Given head, the head of a linked list, determine if the linked list has a cycle in it.

There is a cycle in a linked list if there is some node in the list that can be reached again by continuously following the next pointer. Internally, pos is used to denote the…