Array

Easy | Array, Binary Search, Greedy, Sorting, Prefix Sum

Easy | Array, Hash Table

Easy | Array, Hash Table, String

Medium | Array, Bit Manipulation, Sliding Window

Hard | Array, Hash Table, Sorting, Heap (Priority Queue), Simulation

Easy | Array, Hash Table, Counting

Medium | Array, Two Pointers, Greedy, Sorting, Heap (Priority Queue), Prefix Sum

Hard | Array, Divide and Conquer, Dynamic Programming, Binary Indexed Tree, Segment Tree, Queue, Monotonic Queue

Medium | Array, Two Pointers, Greedy, Sorting

Medium | Array, Binary Search, Bit Manipulation, Sliding Window