A. Find the primes?For a positive integer n, let’s define a function f: f(n) = sum of positive integers less than n whi...

B. Doom of MosquitoesJahid does not like to study. He loves to do other things during his study time. Killing mosquitoes ...

C. Level UpYou are playing a game that has 16 levels. You start with level 1 and after gaining a certain amount...

D. Little DwayneLittle Dwayne Johnson is hosting a programming contest. A lot of teams mail him everyday to ask abou...

E. Unbelievable ArrayYou will be given an array A of n integers and q operations. There are two types of operations: 1 x...

F. Description is PatheticDo you know what is the hardest part of creating a problem? Thinking and writing the description. Yo...

G. Biswa and Restaurant BusinessAfter huge success in Borhani business, Biswa has recently started restaurant business. He’s got the...

H. Nothing’s more contagious than laughterGotham, a city full of criminals. But there is one who is more than just a criminal. He brings pure ...

I. Broken Roads and HeartsHave you heard of the sad story of the place of Banasree? People cannot travel because of the terrib...

J. Selfie RestrictionDo you know the boy named Amlan? The only dream of his life is taking selfies. He takes selfies even...

K. Noora NumberA number is a "Noora" number if the count of distinct digits of the number is equal to the...

L. Towers of DoomAlice and Bob are famous for inventing weird games. They just invented a new game called Towers of D...

M. Sequence QueryYou are given N integer numbers (A1, A2, A3 … AN). You will also be given some query. Each query wil...

Practice contests allow you to rerun contests and experience them as close as possible to the original run.
2Sat, Adhoc, ApolloneasTheorem, Backtracking, BFS, Bignum, BinarySearch, BipartiteMatching, Bitmask, BruteForce, ChineseRemainderTheorem, Combinatorics, ConvexHull, CutVertex, DataStructure, DFS, DigitDP, DisjointSets, DivideAndConquer, DP, Eertree, EulerTour, ExpectedValue, FenwickTree, FFT, Flow, Game, GCD, Geometry, Graph, Greedy, Hashing, HeavyLightDecomposition, Implementation, InclusionExclusion, Interactive, KnuthMorrisPratt, LowestCommonAncestor, Math, Matrix, MatrixExponentiation, MergeSortTree, ModularExponentiation, MOSAlgorithm, MST, NTT, NumberTheory, Parsing, PersistentLiChaoTree, PersistentSegmentTree, PollardRho, PriorityQueue, Probability, Queue, RabinMiller, RangeOrderStatistics, Scheduling, SegmentTree, ShortestPath, Simulation, Sorting, SparseTable, SpragueGrundyTheorem, SqrtDecomposition, Stack, String, StronglyConnectedComponents, SuffixStructure, TernarySearch, Tree, Trie, TwoPointer, WaveletTree