Two Sum Question Given an array of integers nums and an integer target, return indices of the two numbers such that they add up to target.

Merge Two Sorted Lists Question You are given the heads of two sorted linked lists list1 and list2.

Remove Duplicates from Sorted Array Question Given an integer array nums sorted in non-decreasing order, remove the duplicates in-place such that each unique element appears only once.

Remove Element Question Given an integer array nums and an integer val, remove all occurrences of val in nums in-place.

Longest Palindromic Substring Question Given a string s, return the longest palindromic substring in s.

Valid Parentheses Question Given a string s containing just the characters ‘(’, ‘)’, ‘{’, ‘}’, ‘[’ and ‘]’, determine if the input string is valid.