Problems

Very easy · Brute force

Very easy · Math

Very hard · Dynamic programming · Prefix Sums

Very easy · Implementation

Very easy · Brute force

Easy · Math

Easy · Sorting

Very easy · Implementation

Medium · Prefix Sums · Binary Search

Hard · Data Structures · Fenwick Tree · Segment Tree · Greedy algorithms

Medium · Number theory · Strings

Hard · Segment Tree · Range queries · Prefix Sums

Very hard · Dynamic programming · Trees · Depth-first Search · Greedy algorithms · Data Structures

Very easy · Implementation

Medium · Implementation

Easy · Brute force · Bitwise Operations

Medium · Math · Number theory

Very easy · Brute force

Very easy · Sorting

Easy · Graphs · Binary Search

Easy · Strings · Prefix Function

Hard · Greedy algorithms · Sorting · Data Structures · Constructive Algorithms

Very hard · Trees · Combinatorics · Math · Dynamic programming

Very hard · String suffix structures · Hashing · Data Structures · Trees · Strings

Hard · Constructive Algorithms · Bitwise Operations