• Challenges
  • Algorithms
  • Recently Added

    Three PointsNot Completed

    Solutions: 11 | View user solutions | Added 11/08/16

    Eight QueensNot Completed

    Solutions: 7 | View user solutions | Added 11/06/16

    Largest Row ColumnNot Completed

    Solutions: 6 | View user solutions | Added 11/06/16

    You have access to 10 free challenges and solutions below

    Easy Difficulty

    First ReverseNot Completed

    Solutions: 59201 | Step-by-step solution | Challenge discussion

    First FactorialNot Completed

    Solutions: 41281 | Step-by-step solution | Challenge discussion

    Longest WordNot Completed

    Solutions: 33773 | Step-by-step solution | Challenge discussion

    Letter ChangesNot Completed

    Solutions: 31711 | Step-by-step solution | Challenge discussion

    Simple AddingNot Completed

    Solutions: 27726 | Step-by-step solution | Challenge discussion

    Letter CapitalizeNot Completed

    Solutions: 23671 | Step-by-step solution | Challenge discussion

    Simple SymbolsNot Completed

    Solutions: 17746 | Step-by-step solution | Challenge discussion

    Check NumsNot Completed

    Solutions: 19888 | Step-by-step solution | Challenge discussion

    Time ConvertNot Completed

    Solutions: 14864 | Step-by-step solution | Challenge discussion

    Alphabet SoupNot Completed

    Solutions: 14159 | Step-by-step solution | Challenge discussion

    AB CheckNot Completed

    Solutions: 13666 | Step-by-step solution | Challenge discussion

    Vowel CountNot Completed

    Solutions: 13224 | Step-by-step solution | Challenge discussion

    Word CountNot Completed

    Solutions: 12533 | Step-by-step solution | Challenge discussion

    Ex OhNot Completed

    Solutions: 11861 | Step-by-step solution | Challenge discussion

    PalindromeNot Completed

    Solutions: 13710 | Step-by-step solution | Challenge discussion

    Arith GeoNot Completed

    Solutions: 10547 | Step-by-step solution | Challenge discussion

    Array Addition INot Completed

    Solutions: 6549 | Step-by-step solution | Challenge discussion

    Letter Count INot Completed

    Solutions: 5900 | Step-by-step solution | Challenge discussion

    Second GreatLowNot Completed

    Solutions: 10209 | Step-by-step solution | Challenge discussion

    Division StringifiedNot Completed

    Solutions: 7744 | Step-by-step solution | Challenge discussion

    Counting Minutes INot Completed

    Solutions: 4581 | Step-by-step solution | Challenge discussion

    Mean ModeNot Completed

    Solutions: 6091 | Step-by-step solution | Challenge discussion

    Dash InsertNot Completed

    Solutions: 6704 | Step-by-step solution | Challenge discussion

    Swap CaseNot Completed

    Solutions: 6641 | Step-by-step solution | Challenge discussion

    Number AdditionNot Completed

    Solutions: 6441 | Step-by-step solution | Challenge discussion

    Third GreatestNot Completed

    Solutions: 5948 | Step-by-step solution | Challenge discussion

    Powers of TwoNot Completed

    Solutions: 6555 | Step-by-step solution | Challenge discussion

    Additive PersistenceNot Completed

    Solutions: 4490 | Step-by-step solution | Challenge discussion

    Multiplicative PersistenceNot Completed

    Solutions: 3560 | Step-by-step solution | Challenge discussion

    Off Line MinimumNot Completed

    Solutions: 4695 | Step-by-step solution | Challenge discussion

    Changing SequenceNot Completed

    Solutions: 1271 | Step-by-step solution | Challenge discussion

    Overlapping RangesNot Completed

    Solutions: 1286 | Step-by-step solution | Challenge discussion

    SuperincreasingNot Completed

    Solutions: 1264 | Step-by-step solution | Challenge discussion

    Hamming DistanceNot Completed

    Solutions: 851 | Step-by-step solution | Challenge discussion

    Rectangle AreaNot Completed

    Solutions: 1028 | Step-by-step solution | Challenge discussion

    Bitwise OneNot Completed

    Solutions: 869 | Step-by-step solution | Challenge discussion

    Other ProductsNot Completed

    Solutions: 498 | Step-by-step solution | Challenge discussion

    Wave SortingNot Completed

    Solutions: 347 | Step-by-step solution | Challenge discussion

    Array MatchingNot Completed

    Solutions: 404 | Step-by-step solution | Challenge discussion

    Binary ReversalNot Completed

    Solutions: 371 | Step-by-step solution | Challenge discussion

    Longest Increasing SequenceNot Completed

    Solutions: 334 | Step-by-step solution | Challenge discussion

    Even PairsNot Completed

    Solutions: 294 | Step-by-step solution | Challenge discussion

    Next PalindromeNot Completed

    Solutions: 271 | Step-by-step solution | Challenge discussion

    Largest PairNot Completed

    Solutions: 334 | Step-by-step solution | Challenge discussion

    Nonrepeating CharacterNot Completed

    Solutions: 291 | Step-by-step solution | Challenge discussion

    Two SumNot Completed

    Solutions: 475 | Step-by-step solution | Challenge discussion

    Bitwise TwoNot Completed

    Solutions: 177 | Step-by-step solution | Challenge discussion

    Power Set CountNot Completed

    Solutions: 246 | Step-by-step solution | Challenge discussion

    Product DigitsNot Completed

    Solutions: 328 | Step-by-step solution | Challenge discussion

    Palindrome CreatorNot Completed

    Solutions: 260 | Step-by-step solution | Challenge discussion

    Basic Roman NumeralsNot Completed

    Solutions: 209 | Step-by-step solution | Challenge discussion

    Food DistributionNot Completed

    Solutions: 133 | Step-by-step solution | Challenge discussion

    Three SumNot Completed

    Solutions: 164 | Step-by-step solution | Challenge discussion

    Correct PathNot Completed

    Solutions: 85 | Step-by-step solution | Challenge discussion

    Scale BalancingNot Completed

    Solutions: 112 | Step-by-step solution | Challenge discussion

    Three NumbersNot Completed

    Solutions: 97 | Step-by-step solution | Challenge discussion

    Alphabet SearchingNot Completed

    Solutions: 101 | Step-by-step solution | Challenge discussion

    Time DifferenceNot Completed

    Solutions: 34 | Step-by-step solution | Challenge discussion

    Triangle RowNot Completed

    Solutions: 47 | Step-by-step solution | Challenge discussion

    Vowel SquareNot Completed

    Solutions: 47 | Step-by-step solution | Challenge discussion

    Medium Difficulty

    Prime TimeNot Completed

    Solutions: 10468 | Step-by-step solution | Challenge discussion

    Run Length Not Completed

    Solutions: 7275 | Step-by-step solution | Challenge discussion

    Prime MoverNot Completed

    Solutions: 6597 | Step-by-step solution | Challenge discussion

    Palindrome TwoNot Completed

    Solutions: 6092 | Step-by-step solution | Challenge discussion

    DivisionNot Completed

    Solutions: 5496 | Step-by-step solution | Challenge discussion

    String ScrambleNot Completed

    Solutions: 6062 | Step-by-step solution | Challenge discussion

    Arith Geo IINot Completed

    Solutions: 4315 | Step-by-step solution | Challenge discussion

    Array AdditionNot Completed

    Solutions: 3535 | Step-by-step solution | Challenge discussion

    Binary ConverterNot Completed

    Solutions: 4038 | Step-by-step solution | Challenge discussion

    Letter CountNot Completed

    Solutions: 3662 | Step-by-step solution | Challenge discussion

    Simple ModeNot Completed

    Solutions: 4031 | Step-by-step solution | Challenge discussion

    Caesar CipherNot Completed

    Solutions: 4315 | Step-by-step solution | Challenge discussion

    Formatted DivisionNot Completed

    Solutions: 3162 | Step-by-step solution | Challenge discussion

    ConsecutiveNot Completed

    Solutions: 3492 | Step-by-step solution | Challenge discussion

    Counting MinutesNot Completed

    Solutions: 2340 | View all user solutions | Challenge discussion

    Permutation StepNot Completed

    Solutions: 2724 | View all user solutions | Challenge discussion

    Prime CheckerNot Completed

    Solutions: 2087 | View all user solutions | Challenge discussion

    Dash Insert IINot Completed

    Solutions: 4236 | View all user solutions | Challenge discussion

    Swap IINot Completed

    Solutions: 2296 | View all user solutions | Challenge discussion

    Number SearchNot Completed

    Solutions: 2778 | View all user solutions | Challenge discussion

    Triple DoubleNot Completed

    Solutions: 2587 | View all user solutions | Challenge discussion

    Bracket MatcherNot Completed

    Solutions: 2377 | View all user solutions | Challenge discussion

    String ReductionNot Completed

    Solutions: 1994 | View all user solutions | Challenge discussion

    Coin DeterminerNot Completed

    Solutions: 1921 | View all user solutions | Challenge discussion

    ThreeFive MultiplesNot Completed

    Solutions: 2418 | View all user solutions | Challenge discussion

    Fibonacci CheckerNot Completed

    Solutions: 2258 | View all user solutions | Challenge discussion

    Multiple BracketsNot Completed

    Solutions: 1906 | View all user solutions | Challenge discussion

    Most Free TimeNot Completed

    Solutions: 1209 | View all user solutions | Challenge discussion

    Overlapping RectanglesNot Completed

    Solutions: 1360 | View all user solutions | Challenge discussion

    Distinct ListNot Completed

    Solutions: 2056 | View all user solutions | Challenge discussion

    Look Say SequenceNot Completed

    Solutions: 1181 | View all user solutions | Challenge discussion

    Number EncodingNot Completed

    Solutions: 1223 | View all user solutions | Challenge discussion

    Stock PickerNot Completed

    Solutions: 426 | View all user solutions | Challenge discussion

    Max SubarrayNot Completed

    Solutions: 308 | View all user solutions | Challenge discussion

    Missing DigitNot Completed

    Solutions: 213 | View all user solutions | Challenge discussion

    K Unique CharactersNot Completed

    Solutions: 195 | View all user solutions | Challenge discussion

    Bitmap HolesNot Completed

    Solutions: 107 | View all user solutions | Challenge discussion

    Symmetric TreeNot Completed

    Solutions: 115 | View all user solutions | Challenge discussion

    Binary Search Tree LCANot Completed

    Solutions: 116 | View all user solutions | Challenge discussion

    Binary Tree LCANot Completed

    Solutions: 62 | View all user solutions | Challenge discussion

    LRU CacheNot Completed

    Solutions: 50 | View all user solutions | Challenge discussion

    Tree ConstructorNot Completed

    Solutions: 54 | View all user solutions | Challenge discussion

    Array Min JumpsNot Completed

    Solutions: 79 | View all user solutions | Challenge discussion

    Nearest Smaller ValuesNot Completed

    Solutions: 123 | View all user solutions | Challenge discussion

    Matrix SpiralNot Completed

    Solutions: 58 | View all user solutions | Challenge discussion

    Word SplitNot Completed

    Solutions: 102 | View all user solutions | Challenge discussion

    Pair SearchingNot Completed

    Solutions: 40 | View all user solutions | Challenge discussion

    Boggle SolverNot Completed

    Solutions: 28 | View all user solutions | Challenge discussion

    HTML ElementsNot Completed

    Solutions: 36 | View all user solutions | Challenge discussion

    Missing Digit IINot Completed

    Solutions: 48 | View all user solutions | Challenge discussion

    Palindromic SubstringNot Completed

    Solutions: 64 | View all user solutions | Challenge discussion

    Trapping WaterNot Completed

    Solutions: 52 | View all user solutions | Challenge discussion

    Matrix PathNot Completed

    Solutions: 33 | View all user solutions | Challenge discussion

    Seating StudentsNot Completed

    Solutions: 37 | View all user solutions | Challenge discussion

    Longest Matrix PathNot Completed

    Solutions: 19 | View all user solutions | Challenge discussion

    Min Window SubstringNot Completed

    Solutions: 34 | View all user solutions | Challenge discussion

    Matrix ChainsNot Completed

    Solutions: 23 | View all user solutions | Challenge discussion

    Histogram AreaNot Completed

    Solutions: 26 | View all user solutions | Challenge discussion

    Matching CharactersNot Completed

    Solutions: 26 | View all user solutions | Challenge discussion

    Ternary ConverterNot Completed

    Solutions: 16 | View all user solutions | Challenge discussion

    Linear CongruenceNot Completed

    Solutions: 8 | View all user solutions | Challenge discussion

    Formatted NumberNot Completed

    Solutions: 21 | View all user solutions | Challenge discussion

    Largest Row ColumnNot Completed

    Solutions: 6 | View all user solutions | Challenge discussion

    Eight QueensNot Completed

    Solutions: 7 | View all user solutions | Challenge discussion

    Three PointsNot Completed

    Solutions: 11 | View all user solutions | Challenge discussion

    Hard Difficulty

    Shortest PathNot Completed

    Solutions: 885 | View all user solutions | Challenge discussion

    Pattern ChaserNot Completed

    Solutions: 580 | View all user solutions | Challenge discussion

    CalculatorNot Completed

    Solutions: 1007 | View all user solutions | Challenge discussion

    Weighted PathNot Completed

    Solutions: 306 | View all user solutions | Challenge discussion

    Intersecting LinesNot Completed

    Solutions: 495 | View all user solutions | Challenge discussion

    RREF MatrixNot Completed

    Solutions: 103 | View all user solutions | Challenge discussion

    Polynomial ExpansionNot Completed

    Solutions: 260 | View all user solutions | Challenge discussion

    Gas StationNot Completed

    Solutions: 493 | View all user solutions | Challenge discussion

    Symmetric MatrixNot Completed

    Solutions: 345 | View all user solutions | Challenge discussion

    Switch SortNot Completed

    Solutions: 243 | View all user solutions | Challenge discussion

    Matrix DeterminantNot Completed

    Solutions: 236 | View all user solutions | Challenge discussion

    Queen CheckNot Completed

    Solutions: 402 | View all user solutions | Challenge discussion

    Noughts DeterminerNot Completed

    Solutions: 340 | View all user solutions | Challenge discussion

    Blackjack HighestNot Completed

    Solutions: 451 | View all user solutions | Challenge discussion

    Transitivity RelationsNot Completed

    Solutions: 396 | View all user solutions | Challenge discussion

    Alphabet Run EncryptionNot Completed

    Solutions: 220 | View all user solutions | Challenge discussion

    Knight JumpsNot Completed

    Solutions: 478 | View all user solutions | Challenge discussion

    Line OrderingNot Completed

    Solutions: 45 | View all user solutions | Challenge discussion

    Sudoku Quadrant CheckerNot Completed

    Solutions: 87 | View all user solutions | Challenge discussion

    Quick KnightNot Completed

    Solutions: 37 | View all user solutions | Challenge discussion

    Square FiguresNot Completed

    Solutions: 92 | View all user solutions | Challenge discussion

    Connect Four WinnerNot Completed

    Solutions: 61 | View all user solutions | Challenge discussion

    Array JumpingNot Completed

    Solutions: 45 | View all user solutions | Challenge discussion

    Matrix BorderNot Completed

    Solutions: 50 | View all user solutions | Challenge discussion

    Roman Numeral ReductionNot Completed

    Solutions: 55 | View all user solutions | Challenge discussion

    Parallel SumsNot Completed

    Solutions: 71 | View all user solutions | Challenge discussion

    LCSNot Completed

    Solutions: 47 | View all user solutions | Challenge discussion

    Nim WinnerNot Completed

    Solutions: 34 | View all user solutions | Challenge discussion

    Farthest NodesNot Completed

    Solutions: 130 | View all user solutions | Challenge discussion

    Optimal AssignmentsNot Completed

    Solutions: 473 | View all user solutions | Challenge discussion

    Kaprekars ConstantNot Completed

    Solutions: 73 | View all user solutions | Challenge discussion

    Hamiltonian PathNot Completed

    Solutions: 123 | View all user solutions | Challenge discussion

    Vertex CoveringNot Completed

    Solutions: 126 | View all user solutions | Challenge discussion

    Step WalkingNot Completed

    Solutions: 61 | View all user solutions | Challenge discussion

    Pascals TriangleNot Completed

    Solutions: 65 | View all user solutions | Challenge discussion

    Reverse Polish NotationNot Completed

    Solutions: 179 | View all user solutions | Challenge discussion

    Max Heap CheckerNot Completed

    Solutions: 62 | View all user solutions | Challenge discussion

    Chessboard TravelingNot Completed

    Solutions: 40 | View all user solutions | Challenge discussion

    Matching CouplesNot Completed

    Solutions: 72 | View all user solutions | Challenge discussion

    Approaching FibonacciNot Completed

    Solutions: 86 | View all user solutions | Challenge discussion

    Simple SATNot Completed

    Solutions: 45 | View all user solutions | Challenge discussion

    Array CouplesNot Completed

    Solutions: 59 | View all user solutions | Challenge discussion

    Array RotationNot Completed

    Solutions: 95 | View all user solutions | Challenge discussion

    Bracket CombinationsNot Completed

    Solutions: 71 | View all user solutions | Challenge discussion

    Counting AnagramsNot Completed

    Solutions: 81 | View all user solutions | Challenge discussion

    Maximal SquareNot Completed

    Solutions: 19 | View all user solutions | Challenge discussion

    Maximal RectangleNot Completed

    Solutions: 21 | View all user solutions | Challenge discussion

    Bipartite MatchingNot Completed

    Solutions: 15 | View all user solutions | Challenge discussion

    Pentagonal NumberNot Completed

    Solutions: 12 | View all user solutions | Challenge discussion

    City TrafficNot Completed

    Solutions: 15 | View all user solutions | Challenge discussion

    Convex Hull PointsNot Completed

    Solutions: 6 | View all user solutions | Challenge discussion