MAANG Questions

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

Design a data structure that follows the constraints of a Least Recently Used (LRU) cache.

You are given an array of k linked-lists lists, each linked-list is sorted in ascending order. Merge all the linked-lists into one sorted linked-list.

Given a string s containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid.