The Ultimate Topic List

The Ultimate Topic List

A comprehensive list of topics in Competitive Programming

-

/

Completed: ‌
out of 572

Copy Link to Basics

💡 Complete the basic topics in the given order to get started with Competitive Programming.

Intro to Programming

1.

What is Programming?

Learn a Language

💡 Learning C++ is recommended.

2.

Intro to C++ and Setting up the Environment

3.

Data Types, Variables and Input Output

4.

5.

Conditional Statements

6.

7.

8.

9.

10.

Pointers and References

11.

Intro to Competitive Programming

12.

What is Competitive Programming?

Bitwise Thinking

13.

Bitwise Operations and Bitmasks

Complexity Analysis

14.

Big O Notation and Time and Space Complexity Analysis

15.

Fast Input Output

Recursion

16.

Very Basic Math

17.

18.

19.

Harmonic Number

Range Queries Without Updates

20.

21.

Standard Template Library (STL)

22.

Intro to STL, Containers and Iterators

23.

Pairs and Tuples

24.

25.

26.

27.

28.

29.

Set, Unordered Set and Multiset

30.

Map and Unordered Map

31.

32.

List / Linked List

Leveraging Monotonicity

33.

34.

Basic Sorting Algorithms

35.

36.

37.

38.

39.

40.

41.

42.

C++ STL Sort and Custom Comparator

Divide and Conquer

43.

Divide and Conquer

Greedy and Constructive

44.

Basic Greedy Algorithms

45.

Basic Constructive Algorithms

2D Prefix Sum

46.

More Techniques

47.

Difference Array

48.

Sliding Window Technique

Bit Manipulation

49.

Bit Manipulation

50.

Basic Modular Arithmetic

51.

Binary Exponentiation and Basic Modular Arithmetic

52.

Fermat's Little Theorem and Modular Inverse

Basic Counting

53.

Permutations, Combinations and Basic Counting Problems

54.

55.

Pigeonhole Principle

Very Basic Graphs

56.

Introduction to Graphs | Definitions and Representations

Copy Link to Data Structures (DS)

Segment Tree

57.

Segment Tree (Point Update Range Query)

58.

Segment Tree with Lazy Propagation

59.

Persistent Segment Tree

60.

Persistent Segment Tree with Lazy Propagation

61.

2D Segment Tree

62.

Dynamic Segment Tree

63.

2D Dynamic Segment Tree

64.

Merge Sort Tree

65.

Iterative Segment Tree

66.

Segment Tree Merging

67.

Segment Tree Beats

68.

XOR Segment Tree

69.

Historic Information on Segment Trees

Binary Indexed Tree (BIT)

70.

BIT / Fenwick Tree

71.

Lower bound on BIT

72.

BIT with Range Update and Range Query

73.

74.

2D BIT with Range Update and Range Query

Sparse Table

75.

76.

Sparse Table 2D

77.

Disjoint Sparse Table

Trie

78.

Trie on Strings and Bits

79.

Persistent Trie

Disjoint Set Union (DSU)

80.

DSU / Union Find

81.

DSU with Rollbacks

82.

Reachability Tree / DSU Tree / Kruskal Reconstruction Tree (KRT)

83.

Partially Persistent DSU

84.

85.

Augmented DSU / Weighted DSU

86.

DSU on Tree and Small to Large Merging

87.

[Trick] Maintaining Log N DSU / Range Parallel DSU

Square Root Decomposition

88.

Basic SQRT Decomposition

89.

Splitting Objects into Light and Heavy / Case Processing

90.

Batch Processing / SQRT Decomposition on Queries

91.

SQRT Decomposition Split and Build Technique

92.

SQRT Fragmented Tree / Block Tree / SQRT Decomposition on Trees

93.

94.

Rollback Mo and Mo's with DSU

95.

96.

97.

Mo's with Update / 3D Mo (Offline)

98.

Mo's with Update / 3D Mo (Online)

99.

Heavy Light Decomposition (HLD)

100.

Heavy Light Decomposition (HLD) ft Subtrees and Path Query

Centroid Decomposition

101.

Centroid Decomposition

102.

Persistent Centroid Decomposition

Long Path Decomposition

103.

Long Path Decomposition

BST

104.

Binary Search Tree (BST)

Balanced Binary Search Tree (BBST)

105.

106.

107.

Persistent Treap

108.

109.

Link Cut Tree (LCT)

110.

Link Cut Tree (LCT)

111.

Euler Tour Tree (ETT)

112.

Top Tree / AAA Tree

113.

Link Cut Cactus

Policy Based Data Structures

114.

115.

More Tree Data Structures

116.

117.

118.

K-Dimensional Tree (KD Tree)

119.

120.

Permutation Tree

121.

Dynamic Connectivity

122.

Dynamic Connectivity Problem (Offline)

123.

Dynamic Connectivity Problem (Online) / HDLT Algorithm

Monotonic Data Structures

124.

Monotonic Stack: All Nearest Smaller Values and All Subarray Maximum/Minimum

125.

Monotonic Queue

126.

Monotonic Queue 2D

127.

Monotonic Deque

Miscellaneous

128.

129.

Persistent Array

130.

Persistent Queue

131.

Persistent Meldable Heap / Leftist Heap

Techniques

132.

Venice Technique

133.

Offline Queries

134.

Static to Dynamic Trick / Log Decomposition

135.

Divide and Conquer on Queries

136.

CDQ Divide and Conquer

137.

Queue Undo Trick

138.

Priority Queue Undo Trick

Copy Link to Graph Theory

💡 Complete the "Very Basic Graphs" section under the "Basics" category first.

Graph Traversal

139.

Depth First Search (DFS)

140.

Breadth First Search (BFS)

141.

142.

Topological Sorting

143.

144.

Euler Tour Technique

145.

Lowest Common Ancestor (LCA)

146.

Binary Lifting and LCA

147.

Graph Connectivity

148.

Strongly Connected Components (SCC)

149.

Incremental SCC

150.

Articulation Bridges and Bridge Tree

151.

Online Articulation Bridges

152.

Articulation Points and Block Cut Tree

153.

Three Edge Connectivity

154.

Four Edge Connectivity

155.

Dynamic K-Connectivity

156.

Ear Decomposition

Orientation

157.

Strong Orientation

158.

ST-numbering / Bipolar Orientation

Minimum Spanning Tree (MST)

159.

Minimum Spanning Tree (Prim's and Kruskal's)

160.

Steiner Tree Problem

161.

Boruvka's Algorithm

162.

Minimum Diameter Spanning Tree

163.

164.

165.

166.

167.

Kirchoffs Theorem ft Number of MSTs

Shortest Paths

168.

Dijkstra's Algorithm

169.

[Trick] Dijkstra on Segment Tree

170.

171.

172.

Shortest Path Faster Algorithm (SPFA)

173.

Johnson's Alogrithm

174.

175.

Dial's algorithm

176.

Eppsteins Algorithm

177.

Suurballe's Algorithm

178.

Cycles

179.

Cycle Detection

180.

[Problem] Minimum Weight Cycle For Each Vertex

181.

[Problem] Minimum Weight Cycle For Each Edge

182.

Minimum Mean Weight Cycle

183.

Number of 3 and 4 length Cycles

More Tree Stuff

184.

Virtual Tree / Auxiliary Tree

185.

Rerooting Technique

186.

Union of Two Paths on a Tree

187.

Intersection of Two Paths on a Tree

188.

[Problem] Number of Paths of Each Length in a Tree

189.

Dynamic Online Tree Diameter

190.

[Problem] Tree Orientation to Maximize Pairs of Reachable Nodes

Satisfiability

191.

192.

193.

System Of Difference Constraints

Eulerian Path

194.

Eulerian Path and Cycle

Hamiltonian Path

195.

Hamiltonian Path and Cycle

196.

Hamiltonian Path Heuristic Algorithm

Cliques and Independent Sets

197.

198.

Maximum Independent Set (MIS)

Graph Coloring

199.

Chromatic Number

200.

Welsh-Powell Algorithm

201.

Chromatic Polynomial ft Number of DAGs

202.

Edge Coloring of Simple Graph

203.

Edge Coloring of Bipartite Graph

Graph Counting

204.

Counting Labeled Graphs

205.

206.

[Problem] Number of Arborescences with n Nodes

207.

Tuttes Theorem ft Arborescences in a Graph

208.

Dynamic Acyclic Graphs (DAG)

209.

DAG Reachability

210.

Incremental DAG Reachability

Dominators

211.

Special Graphs

212.

213.

Tournament Graph

214.

Flow and Min Cut

215.

Maximum Flow / Minimum Cut

216.

Min Cost Max Flow (MCMF)

217.

Min Cost Max Flow with Negative Cycles

218.

Maximum Closure Problem

219.

220.

221.

Gomory-Hu Tree of a Planar Graph

222.

Stoer Wagner Algorithm

223.

Chinese Postman Problem

224.

Uniqueness of Min Cut

225.

Maximum Density Subgraph

226.

Min Cut in a Planar Graph

227.

Max Cut in a Planar Graph

Matching

228.

Bipartite Matching (HopCroft Karp Algorithm and Kuhn's Algorithm)

229.

Hungarian Algorithm / Bipartite Weighted Matching

230.

Blossom Algorithm Unweighted / General Matching / Randomized General Matching

231.

Blossom Algorithm Weighted / General Weighted Matching

232.

Stable Marriage Problem

233.

Konig's Theorem and Maximum Independent Set in Bipartite Graphs

234.

235.

Matching using Determinants

Partially Ordered Set (POSET)

236.

POSET ft Dilworth's and Mirsky's Theorem

Miscellaneous

237.

Functional Graphs

238.

Degree Sequences

239.

Tree Isomorphism

240.

Binarizing a Tree

241.

Planarity Check

Copy Link to Number Theory

Primes and Divisors

242.

Sieve, Prime Factorization and Divisors

243.

244.

Segmented Sieve

245.

246.

Miller-Rabin Primality Test

247.

248.

Prime Counting Function

249.

250.

[Problem] Counting Numbers Having Exactly K Divisors

251.

[Problem] Smallest Number Having Exactly K Divisors

252.

Sum of The Number of Divisors in cbrt(n)

253.

Wilson's Theorem

254.

Implicit Prime Factorization

Multiplicative Functions

255.

Number of Divisors / Sum of Divisors / Sigma Function

256.

Euler's Totient Function / Phi Function

257.

Power Tower / Generalized Euler theorem

258.

Mobius Function and Mobius Inversion

259.

Dirichlet convolution

260.

261.

Powerful Number Sieve / PN Sieve

Euclidean Algorithm

262.

Euclidean Algorithm

263.

Extended Euclid

264.

Bezout's Identity

265.

Chicken McNugget Theorem

Modular Arithmetic

266.

Linear Congruence Equation

267.

Chinese Remainder Theorem (CRT)

268.

269.

Multiplicative Order and Carmichael's Lambda Function

270.

Discrete Log / Baby Step Giant Step

271.

272.

Discrete Root in O(P^(1/4))

273.

Discrete Square Root, Tonelli Shanks Algorithm, Cipolla's Algorithm

274.

Number of Distinct Kth Powers Modulo N

275.

Number of Solutions to X^2 = 1 mod M

Linear Diophantine Equations

276.

Linear Diophantine Equation with Two Variables

277.

Linear Diophantine Equation with N Variables

278.

Trivariable Linear Diophantine Equation with Nonnegative Solutions

279.

Multivariable Linear Diophantine Equation with Nonnegative Solutions

280.

Linear Diophantine With N Unknowns and Two Equations

Solutions to Equations

281.

Number of Solutions to a Basic Linear Algebraic Equation

282.

Number of Solutions to a Basic Linear Algebraic Equation using Meet in the Middle

283.

Number of Nonnegative Integer Solutions to ax + by ≤ c

284.

Number of Integer Solutions to 1/x + 1/y = 1/k

285.

Two / Three / Four Squares Theorem

286.

Pell's Equation

Floor Sum

287.

288.

Floor Sum and Mod Sum of Arithmetic Progression

289.

Generalized Floor Sum of Arithmetic Progression

Fibonacci Numbers

290.

Fibonacci Numbers

291.

[Problem] LCM of Fibonacci Numbers

292.

293.

Miscellaneous

294.

Pythagorean Triplets

295.

Min of Mod of Arithmetic Progression

296.

Factorial Number System

297.

Stern-Brocot Tree and Rational Approximation

298.

[Problem] Number of a * x mod p in a Range

299.

[Problem] Smallest Nonnegative Integer x s.t. l ≤ a * x mod p ≤ r

Copy Link to Combinatorics

💡 Complete the "Basic Counting" section under the "Basics" category first.

Techniques

300.

Contribution Technique

Catalan

301.

Catalan Numbers

302.

Catalan Convolution

Inclusion Exclusion

303.

Principle of Inclusion and Exclusion (PIE)

304.

305.

Inclusion Exclusion on Multiples

Factorials and Binomial Coefficients (nCr)

306.

307.

nCr Modulo Any Mod

308.

Large Factorials and Binomial Coefficients

309.

Legendre's Formula

310.

Prefix Sum Queries of Binomial Coefficients

311.

Prefix Sum of Binomial Coefficients for a Fixed Large N

312.

Sum of nCr Over a Fixed Congruence Class

313.

[Problem] Sum of nCr(a[i], K) for each K from 1 to N

Stirling Numbers

314.

Stirling Numbers (Basic)

315.

Stirling Number of the First Kind for Fixed N

316.

Stirling Number of the First Kind for Fixed K

317.

Stirling Number of the Second Kind for Fixed N

318.

Stirling Number of the Second Kind for Fixed K

Partitions

319.

Partitions of an Integer, Partition Function and Pentagonal Number Theorem

320.

Partitions of a Set / Bell Number

Miscellaneous

321.

Burnside's Lemma / Polya Enumeration Theorem

322.

Bertrand's Ballot Theorem

323.

Young Tableaus and the Hook Length Formula

Copy Link to Math

Convolution

324.

Fast Fourier Transform (FFT)

325.

Number Theoretic Transform (NTT)

326.

327.

Online FFT / NTT

328.

Fast Walsh Hadamard Transform (FWHT) and its Variations

329.

GCD Convolution

330.

LCM Convolution

Polynomial

331.

Generating Functions

332.

Polynomial Inverse

333.

334.

335.

336.

Polynomial Sqrt

337.

Polynomial Composition

338.

Multipoint Evaluation

339.

Chirp Z Transform

340.

Polynomial Interpolation

341.

Polynomial Shift

342.

Shift of Sampling Points of Polynomial

343.

Polyomial Division and Remainder

344.

Polynomial Roots Under a Modulo

345.

Resultant of Two Polynomials and Half-GCD Algorithm

346.

Lagrange Interpolation

347.

[Problem] Sum of r^i * poly(i)

348.

Polynomial with Binomial Coefficients

349.

Subset Sum Problem using Generating Functions

350.

Polynomial Factorization of (x^n - 1) and Cyclotomic Polynomials

351.

Schwartz–Zippel Lemma

352.

Lagrange Inversion Theorem

Matrices

353.

Matrix Exponentiation

354.

Permanent of a Matrix

355.

Freivald's Algorithm

356.

Vandermonde Matrix

357.

Hafnian of a Matrix / Number of Perfect Matchings in a Graph

358.

Frobenius Form of a Matrix and Fast Matrix Power

Linear Recurrence

359.

Linear Recurrence Relations

360.

Linear Recurrence using Cayley-Hamilton Theorem in O(N^2 log K)

361.

Linear Recurrence using Generating Functions in O(N log N log K)

362.

Linear Recurrence with Polynomial Coefficients

363.

Linear Recurrence on Matrices

364.

Generating Function of a Linear Recurrence

365.

Berlekamp Massey

366.

Reeds-Sloane Algorithm

Linear Algebra

367.

Gaussian Elimination

368.

Gaussian Elimination Modulo 2

369.

Determinant of a Matrix

370.

Determinant under Composite Modulo

371.

Characteristic Polynomial and Hesserberg Matrix

372.

[Problem] Determinant of Product Matrix

373.

Determinant of Sparse Matrix and Black Box Linear Algebra

374.

[Problem] Determinant of Permutant and Circulant Matrix

375.

GCD Determinant / Smith's Determinant

376.

Cauchy–Binet formula

377.

Inverse of a Matrix

378.

Inverse of a Matrix modulo 2

379.

Thomas Algorithm

380.

Vector Space and XOR Basis

381.

[Technique] XOR Basis ft Reduced Row Echelon Form

382.

[Technique] XOR Basis ft Lexicographically Largest Basis

383.

XOR Basis with Deletions (Online)

384.

Formulas

385.

Gauss's Eureka Theorem

386.

387.

Lifting-the-exponent(LTE) Lemma

388.

Faulhaber's Formula and Bernoulli Numbers

Calculus

389.

Differentiation and Integration

390.

Probabilities and Expected Values

391.

Probabilities and Expected Values

392.

Expected Value Powers Technique

393.

The Slime Trick

394.

Expected Occurrence Time as Substring

395.

396.

Mathematical Optimization

397.

Lagrange Multiplier

398.

Linear Programming / Simplex Algorithm

399.

Duality in Linear Programming (LP <> Flow)

Miscellaneous

400.

Continued Fractions

401.

Polynomial Real Roots

402.

Finite Field Arithmetic Binary

Copy Link to Strings

String Matching

403.

Knuth Morris Pratt (KMP) and Prefix Automaton

404.

405.

String Matching using Bitsets

406.

String Matching with FFT ft Wildcard Matching

Hashing

407.

408.

2D String Hashing

409.

410.

Multiset Hashing

Aho Corasick

411.

412.

Dynamic Aho Corasick

Suffix Structures

413.

414.

Isomorphic Suffix Array

415.

Dynamic Suffix Array

416.

Suffix Automaton

417.

[Problem] Distinct Substring Queries in Range

418.

Palindromes

419.

Palindromic Tree

420.

Persistent Palindromic Tree

421.

Manachers Algorithm

422.

[Problem] Minimum Palindrome Factorization

423.

[Problem] Number of Palindromes in Range

Longest Common Subsequence (LCS)

424.

Longest Common Subsequence (LCS)

425.

All Substring Longest Common Subsequence

426.

427.

428.

LCS on RLE compressed string

Miscellaneous

429.

Balanced Brackets

430.

Expression Parsing

431.

Lyndon Factorization / Duval Algorithm

432.

Finding Repetitions / Main-Lorentz Algorithm

433.

De Bruijn Sequence

Copy Link to Dynamic Programming (DP)

Intro to DP

434.

Knapsack and Basic Dynamic Programming

435.

Knapsack and Subset Sum Optimizations

Digit DP

436.

DP Optimizations

437.

Divide and Conquer Optimization

438.

Knuth Optimization

439.

Aliens Trick / WQS Binary Search

440.

1D1D DP Optimization

441.

DP Optimization using Data Structures [Some Practice Problems]

Convex Hull Trick (CHT)

442.

Convex Hull Trick (CHT) and Dynamic CHT

443.

Li Chao Tree

444.

445.

Persistent Li Chao Tree

446.

Extended Li Chao tree

Bit Related DP

447.

448.

Sum Over Subsets DP (SOS DP)

449.

[Problem] Subset Union of Bitsets

450.

Subset Convolution

451.

[Trick] Dynamic Submask Count

452.

[Problem] XOR Equation

More Tricks

453.

Open and Close Interval Trick

454.

455.

456.

Combining Subtrees Technique

Classic DP

457.

Longest Increasing Subsequence (LIS)

458.

Interval DP / Range DP / Matrix Chain Multiplication (MCM)

459.

Dp on Different Structures

460.

DP on Trees and DAGs

461.

DP over Divisors

462.

463.

DP on Convex Hulls

Miscellaneous

464.

Connected Component DP

465.

Broken Profile DP / Plug DP

466.

Hirschberg's Algorithm

467.

[Problem] Number of Subsequences Having Product at least K

468.

[Problem] Range LIS Query

Copy Link to Game Theory

Grundy Number / Nim

469.

Grundy Number and Basic Game Theory

470.

Hackenbush

471.

Green Hackenbush on Trees and Graphs

472.

Blue Red HackenBush

Graph Games

473.

Games on Arbitrary Graphs

474.

[Problem] Matching Game On A Graph

Miscellaneous

475.

Alpha Beta Pruning

Copy Link to Geometry

Euclidean Geometry

476.

Euclidean Geometry

Geometry 2D

477.

Points, Vectors, Transformations, Dot Products, Cross Products, Precision Issues and Polar Sort(2D)

478.

Lines, Segments, Rays, Distance and Relation Between Two Structures, Projections and Reflections(2D)

479.

Circles, Circle Relations, Intersections, Inscribed Circles and Circumcircles(2D)

480.

481.

Circles of Apollonius(2D)

482.

Circle Union(2D)

483.

484.

Centroid of a Polygon(2D)

485.

Geometric Median(2D)

486.

Convex Hull(2D)

487.

Point in Convex Polygon in log(N)(2D)

488.

Winding Number and Point in Simple Polygon(2D)

489.

Extreme Vertex(2D)

490.

Rotating Calipers ft Diameter and Width of a Convex Polygon and Minimum Enclosing Rectangle(2D)

491.

Minimum Enclosing Circle(2D)

492.

Polygon Line and Convex Line Intersection, and Polygon Cutting(2D)

493.

Tangents from Point to Convex and Convex to Convex(2D)

494.

Distance from Point to Convex, Convex to Line and Convex to Convex(2D)

495.

Maximum Distance from Convex to Convex(2D)

496.

Polygon Union(2D)

497.

Polygon Triangulation(2D)

498.

Maximum Circle Cover(2D)

499.

Maximum Inscribed Circle in a Convex(2D)

500.

Triangle Circle and Polygon Circle Intersection(2D)

Geometry 3D

501.

Points, Vectors, Dot Products, Cross Products and Mixed Products(3D)

502.

503.

Plane Based Coordinate System(3D)

504.

Lines, Segments, and Distances, Angles and Intersections Between Lines and Planes(3D)

505.

Triangles and Distance from Triangle to Triangle(3D)

506.

Spherical Geometry and Winding Number(3D)

507.

Minimum Enclosing Sphere(3D)

508.

Polyhedron, Pyramid, Cone and Cylinder(3D)

509.

Convex Hull(3D)

Delaunay

510.

Delaunay Triangulation and Voronoi Diagram

Half Plane

511.

Half Plane Intersection

512.

Dynamic Half Plane Intersection

Convex Polygon

513.

514.

Dynamic Convex Hull

515.

Onion Decomposition

Lattice Points

516.

517.

Lattice Points inside a Non-Lattice Polygon

Sweep Line

518.

Sweep Line Algorithm and Radial Sweep

519.

Closest Pair of Points

520.

Rectangle Union

521.

All Pair Segment Intersection.

522.

Vertical decomposition

Planar Geometry

523.

Faces in Planar Graph

524.

Miscellaneous

525.

Hill Climbing and Simulated Annealing

526.

[Trick] Linear Combination of Vectors

527.

Reflections on a Rectangle

528.

[Problem] Maximum Area of a Triangle from Given Lengths

529.

[Problem] Maximum Area of a Polygon using Given Lengths in CCW Order

530.

[Problem] Circle/Polygon Inclusion Tree

Copy Link to Miscellaneous

Greedy Algorithms

531.

Activity Selection Problem

532.

Fractional Knapsack Problem

533.

534.

Exchange Arguments

Search Techniques

535.

536.

Parallel Binary Search

537.

Fraction Binary Search

538.

Fracturing Search

Interactive Problems

539.

Interactive Problems

540.

Interactive Problems on Centroids

Permutations

541.

Permutations and Permutation Cycles

542.

[Problem] K-th Root of a Permutation

543.

Schreier–Sims Algorithm

Matroids

544.

Matroid Intersection

Chess

545.

[Problem] Knight Moves in Infinity Grid

546.

[Problem] Knight's Tour Problem

547.

[Problem] Bishop Placement

Techniques

548.

Coordinate Compression

549.

Direction Array

550.

Meet in the Middle

551.

Invariants and Monovariants

552.

Manhattan <> Chebyshev

553.

LCM OR Technique

554.

[Trick] Logarithmic Subarray Aggregator (LSA Trick)

555.

Bitwise Disjoint Partitioning

556.

[Trick] Efficient Non-Increasing Sequence Recovery of Length n with a[i] <= n/i

Min Plus Convolution

557.

Min Plus Convolution (Convex and Convex)

558.

SMAWK Algorithm and Min Plus Convolution (Convex and Arbitrary)

Randomized

559.

Randomized Algorithms

560.

Birthday Paradox

Bigint

561.

562.

Miscellaneous

563.

564.

Josephus Problem

565.

566.

567.

[Problem] MEX of all Subarrays

568.

Lindstrom Gessel Viennot(LGV) Lemma

569.

Dynamic Bitsets

570.

571.

Boyer–Moore Voting Algorithm and Misra–Gries Algorithm

572.

Heavy Implementation Problems

Useful Links

Codeforces — The most famous platform for practicing problems and participating in contests
Atcoder — Another great platform for practicing problems and participating in contests
Codechef — A decent platform for practicing problems and participating in contests
Codeforces Catalog — All useful blogs categorized at one place
A list of almost all useful blogs ever published on Codeforces — By parveen1981
(Plenty of) useful blogs in CodeForces — By tallnut_liu
Helpful Codeforces Extensions — By MohamedAboOkail
Stress Testing — By C137
Atcoder Problems — A great resource for practicing problems on Atcoder
CSES Problem Set — A great collection of classic problems
Library Checker — An online judge for testing your library
Vjudge — A virtual judge system for creating mashup contests and practicing problems from various competitive programming websites
StopStalk — Track your progress on various competitive programming websites at one place
CP Algorithms — A great resource for Algorithms for Competitive Programming
USACO Guide — A free collection of curated, high-quality resources
VisuAlgo — Visualising data structures and algorithms through animation
Graph Editor — CSAcademy
A List of Useful Equations in Competitive Programming — By YouKn0wWho
CP Trainer — By Michal Opala

Total Practice Problems Solved: ‌
out of 3888

Author: YouKn0wWho

Report Bugs: Join Discord

Total Views: ‌

Backup, Open Source, Static Website