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    WildcardsNot Completed

    Solutions: 26 | View user solutions | Added 09/12/18

    String CalculateNot Completed

    Solutions: 20 | View user solutions | Added 09/10/18

    PrimesNot Completed

    Solutions: 53 | View user solutions | Added 08/29/18

    Free Challenges

    Longest WordNot Completed

    Solutions: 79480 | Step-by-step solution | Challenge discussion

    First FactorialNot Completed

    Solutions: 99552 | Step-by-step solution | Challenge discussion

    First ReverseNot Completed

    Solutions: 120820 | Step-by-step solution | Challenge discussion

    Letter ChangesNot Completed

    Solutions: 75123 | Step-by-step solution | Challenge discussion

    Simple AddingNot Completed

    Solutions: 61269 | Step-by-step solution | Challenge discussion

    Letter CapitalizeNot Completed

    Solutions: 52062 | Step-by-step solution | Challenge discussion

    Simple SymbolsNot Completed

    Solutions: 44290 | Step-by-step solution | Challenge discussion

    Check NumsNot Completed

    Solutions: 44856 | Step-by-step solution | Challenge discussion

    Time ConvertNot Completed

    Solutions: 34196 | Step-by-step solution | Challenge discussion

    Alphabet SoupNot Completed

    Solutions: 31368 | Step-by-step solution | Challenge discussion

    Kaprekars ConstantNot Completed

    Solutions: 5405 | View all user solutions | Challenge discussion

    Chessboard TravelingNot Completed

    Solutions: 2343 | View all user solutions | Challenge discussion

    Maximal SquareNot Completed

    Solutions: 1497 | View all user solutions | Challenge discussion

    Pentagonal NumberNot Completed

    Solutions: 1598 | View all user solutions | Challenge discussion

    Correct PathNot Completed

    Solutions: 1744 | View all user solutions | Challenge discussion

    Scale BalancingNot Completed

    Solutions: 2378 | View all user solutions | Challenge discussion

    Vowel SquareNot Completed

    Solutions: 1513 | View all user solutions | Challenge discussion

    Eight QueensNot Completed

    Solutions: 1220 | View all user solutions | Challenge discussion

    Closest Enemy IINot Completed

    Solutions: 1352 | View all user solutions | Challenge discussion

    Questions MarksNot Completed

    Solutions: 3961 | View all user solutions | Challenge discussion

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    Easy Difficulty

    First ReverseNot Completed

    Solutions: 120820 | Step-by-step solution | Challenge discussion

    First FactorialNot Completed

    Solutions: 99552 | Step-by-step solution | Challenge discussion

    Longest WordNot Completed

    Solutions: 79480 | Step-by-step solution | Challenge discussion

    Letter ChangesNot Completed

    Solutions: 75123 | Step-by-step solution | Challenge discussion

    Simple AddingNot Completed

    Solutions: 61269 | Step-by-step solution | Challenge discussion

    Letter CapitalizeNot Completed

    Solutions: 52062 | Step-by-step solution | Challenge discussion

    Simple SymbolsNot Completed

    Solutions: 44290 | Step-by-step solution | Challenge discussion

    Check NumsNot Completed

    Solutions: 44856 | Step-by-step solution | Challenge discussion

    Time ConvertNot Completed

    Solutions: 34196 | Step-by-step solution | Challenge discussion

    Alphabet SoupNot Completed

    Solutions: 31368 | Step-by-step solution | Challenge discussion

    AB CheckNot Completed

    Solutions: 17087 | Step-by-step solution | Challenge discussion

    Vowel CountNot Completed

    Solutions: 15700 | Step-by-step solution | Challenge discussion

    Word CountNot Completed

    Solutions: 14819 | Step-by-step solution | Challenge discussion

    Ex OhNot Completed

    Solutions: 14527 | Step-by-step solution | Challenge discussion

    PalindromeNot Completed

    Solutions: 16929 | Step-by-step solution | Challenge discussion

    Arith GeoNot Completed

    Solutions: 13489 | Step-by-step solution | Challenge discussion

    Array Addition INot Completed

    Solutions: 8695 | Step-by-step solution | Challenge discussion

    Letter Count INot Completed

    Solutions: 7943 | Step-by-step solution | Challenge discussion

    Second GreatLowNot Completed

    Solutions: 13160 | Step-by-step solution | Challenge discussion

    Division StringifiedNot Completed

    Solutions: 9850 | Step-by-step solution | Challenge discussion

    Counting Minutes INot Completed

    Solutions: 5859 | Step-by-step solution | Challenge discussion

    Mean ModeNot Completed

    Solutions: 7646 | Step-by-step solution | Challenge discussion

    Dash InsertNot Completed

    Solutions: 8669 | Step-by-step solution | Challenge discussion

    Swap CaseNot Completed

    Solutions: 8198 | Step-by-step solution | Challenge discussion

    Number AdditionNot Completed

    Solutions: 8081 | Step-by-step solution | Challenge discussion

    Third GreatestNot Completed

    Solutions: 7487 | Step-by-step solution | Challenge discussion

    Powers of TwoNot Completed

    Solutions: 8372 | Step-by-step solution | Challenge discussion

    Additive PersistenceNot Completed

    Solutions: 5979 | Step-by-step solution | Challenge discussion

    Multiplicative PersistenceNot Completed

    Solutions: 4600 | Step-by-step solution | Challenge discussion

    Off Line MinimumNot Completed

    Solutions: 6189 | Step-by-step solution | Challenge discussion

    Changing SequenceNot Completed

    Solutions: 2583 | Step-by-step solution | Challenge discussion

    Overlapping RangesNot Completed

    Solutions: 2597 | Step-by-step solution | Challenge discussion

    SuperincreasingNot Completed

    Solutions: 2646 | Step-by-step solution | Challenge discussion

    Hamming DistanceNot Completed

    Solutions: 1811 | Step-by-step solution | Challenge discussion

    Rectangle AreaNot Completed

    Solutions: 2189 | Step-by-step solution | Challenge discussion

    Bitwise OneNot Completed

    Solutions: 1779 | Step-by-step solution | Challenge discussion

    Other ProductsNot Completed

    Solutions: 1844 | Step-by-step solution | Challenge discussion

    Wave SortingNot Completed

    Solutions: 1276 | Step-by-step solution | Challenge discussion

    Array MatchingNot Completed

    Solutions: 1583 | Step-by-step solution | Challenge discussion

    Binary ReversalNot Completed

    Solutions: 1296 | Step-by-step solution | Challenge discussion

    Longest Increasing SequenceNot Completed

    Solutions: 1248 | Step-by-step solution | Challenge discussion

    Even PairsNot Completed

    Solutions: 1200 | Step-by-step solution | Challenge discussion

    Next PalindromeNot Completed

    Solutions: 1045 | Step-by-step solution | Challenge discussion

    Largest PairNot Completed

    Solutions: 1390 | Step-by-step solution | Challenge discussion

    Nonrepeating CharacterNot Completed

    Solutions: 1051 | Step-by-step solution | Challenge discussion

    Two SumNot Completed

    Solutions: 1907 | Step-by-step solution | Challenge discussion

    Bitwise TwoNot Completed

    Solutions: 750 | Step-by-step solution | Challenge discussion

    Power Set CountNot Completed

    Solutions: 1084 | Step-by-step solution | Challenge discussion

    Product DigitsNot Completed

    Solutions: 1362 | Step-by-step solution | Challenge discussion

    Palindrome CreatorNot Completed

    Solutions: 1148 | Step-by-step solution | Challenge discussion

    Basic Roman NumeralsNot Completed

    Solutions: 756 | Step-by-step solution | Challenge discussion

    Food DistributionNot Completed

    Solutions: 647 | Step-by-step solution | Challenge discussion

    Three SumNot Completed

    Solutions: 768 | Step-by-step solution | Challenge discussion

    Correct PathNot Completed

    Solutions: 1744 | Step-by-step solution | Challenge discussion

    Scale BalancingNot Completed

    Solutions: 2378 | Step-by-step solution | Challenge discussion

    Three NumbersNot Completed

    Solutions: 753 | Step-by-step solution | Challenge discussion

    Alphabet SearchingNot Completed

    Solutions: 625 | Step-by-step solution | Challenge discussion

    Time DifferenceNot Completed

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

    Triangle RowNot Completed

    Solutions: 387 | Step-by-step solution | Challenge discussion

    Vowel SquareNot Completed

    Solutions: 1513 | Step-by-step solution | Challenge discussion

    Closest EnemyNot Completed

    Solutions: 593 | Step-by-step solution | Challenge discussion

    Closest Enemy IINot Completed

    Solutions: 1352 | Step-by-step solution | Challenge discussion

    Number StreamNot Completed

    Solutions: 400 | Step-by-step solution | Challenge discussion

    Largest FourNot Completed

    Solutions: 583 | Step-by-step solution | Challenge discussion

    Distinct CharactersNot Completed

    Solutions: 423 | Step-by-step solution | Challenge discussion

    Questions MarksNot Completed

    Solutions: 3961 | Step-by-step solution | Challenge discussion

    Camel CaseNot Completed

    Solutions: 506 | Step-by-step solution | Challenge discussion

    ASCII ConversionNot Completed

    Solutions: 346 | Step-by-step solution | Challenge discussion

    Simple EvensNot Completed

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

    Snake CaseNot Completed

    Solutions: 411 | Step-by-step solution | Challenge discussion

    Sum MultiplierNot Completed

    Solutions: 507 | Step-by-step solution | Challenge discussion

    String MergeNot Completed

    Solutions: 486 | Step-by-step solution | Challenge discussion

    One DecrementedNot Completed

    Solutions: 452 | Step-by-step solution | Challenge discussion

    Element MergerNot Completed

    Solutions: 477 | Step-by-step solution | Challenge discussion

    GCFNot Completed

    Solutions: 453 | Step-by-step solution | Challenge discussion

    Serial NumberNot Completed

    Solutions: 615 | Step-by-step solution | Challenge discussion

    String PeriodsNot Completed

    Solutions: 513 | Step-by-step solution | Challenge discussion

    Palindrome SwapperNot Completed

    Solutions: 325 | Step-by-step solution | Challenge discussion

    Remove BracketsNot Completed

    Solutions: 471 | Step-by-step solution | Challenge discussion

    Command LineNot Completed

    Solutions: 210 | Step-by-step solution | Challenge discussion

    Star RatingNot Completed

    Solutions: 443 | Step-by-step solution | Challenge discussion

    Moving MedianNot Completed

    Solutions: 181 | Step-by-step solution | Challenge discussion

    Group TotalsNot Completed

    Solutions: 176 | Step-by-step solution | Challenge discussion

    String ChangesNot Completed

    Solutions: 63 | Step-by-step solution | Challenge discussion

    FizzBuzzNot Completed

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

    H DistanceNot Completed

    Solutions: 48 | Step-by-step solution | Challenge discussion

    Different CasesNot Completed

    Solutions: 59 | Step-by-step solution | Challenge discussion

    Medium Difficulty

    Prime TimeNot Completed

    Solutions: 12105 | Step-by-step solution | Challenge discussion

    Run Length Not Completed

    Solutions: 8631 | Step-by-step solution | Challenge discussion

    Prime MoverNot Completed

    Solutions: 7470 | Step-by-step solution | Challenge discussion

    Palindrome TwoNot Completed

    Solutions: 7163 | Step-by-step solution | Challenge discussion

    DivisionNot Completed

    Solutions: 6662 | Step-by-step solution | Challenge discussion

    String ScrambleNot Completed

    Solutions: 7316 | Step-by-step solution | Challenge discussion

    Arith Geo IINot Completed

    Solutions: 5008 | Step-by-step solution | Challenge discussion

    Array AdditionNot Completed

    Solutions: 4455 | Step-by-step solution | Challenge discussion

    Binary ConverterNot Completed

    Solutions: 4537 | Step-by-step solution | Challenge discussion

    Letter CountNot Completed

    Solutions: 4501 | Step-by-step solution | Challenge discussion

    Caesar CipherNot Completed

    Solutions: 5161 | Step-by-step solution | Challenge discussion

    Simple ModeNot Completed

    Solutions: 5024 | Step-by-step solution | Challenge discussion

    ConsecutiveNot Completed

    Solutions: 4121 | Step-by-step solution | Challenge discussion

    Formatted DivisionNot Completed

    Solutions: 3801 | Step-by-step solution | Challenge discussion

    Counting MinutesNot Completed

    Solutions: 2799 | View all user solutions | Challenge discussion

    Permutation StepNot Completed

    Solutions: 3336 | View all user solutions | Challenge discussion

    Prime CheckerNot Completed

    Solutions: 2559 | View all user solutions | Challenge discussion

    Dash Insert IINot Completed

    Solutions: 4937 | View all user solutions | Challenge discussion

    Swap IINot Completed

    Solutions: 2754 | View all user solutions | Challenge discussion

    Number SearchNot Completed

    Solutions: 3372 | View all user solutions | Challenge discussion

    Triple DoubleNot Completed

    Solutions: 3128 | View all user solutions | Challenge discussion

    Bracket MatcherNot Completed

    Solutions: 2851 | View all user solutions | Challenge discussion

    String ReductionNot Completed

    Solutions: 2357 | View all user solutions | Challenge discussion

    ThreeFive MultiplesNot Completed

    Solutions: 2851 | View all user solutions | Challenge discussion

    Binary Search Tree LCANot Completed

    Solutions: 288 | View all user solutions | Challenge discussion

    Coin DeterminerNot Completed

    Solutions: 2314 | View all user solutions | Challenge discussion

    Fibonacci CheckerNot Completed

    Solutions: 2657 | View all user solutions | Challenge discussion

    Multiple BracketsNot Completed

    Solutions: 2363 | View all user solutions | Challenge discussion

    Most Free TimeNot Completed

    Solutions: 1428 | View all user solutions | Challenge discussion

    Overlapping RectanglesNot Completed

    Solutions: 1626 | View all user solutions | Challenge discussion

    Look Say SequenceNot Completed

    Solutions: 1483 | View all user solutions | Challenge discussion

    Distinct ListNot Completed

    Solutions: 2408 | View all user solutions | Challenge discussion

    Number EncodingNot Completed

    Solutions: 1496 | View all user solutions | Challenge discussion

    Stock PickerNot Completed

    Solutions: 744 | View all user solutions | Challenge discussion

    Max SubarrayNot Completed

    Solutions: 666 | View all user solutions | Challenge discussion

    Missing DigitNot Completed

    Solutions: 453 | View all user solutions | Challenge discussion

    K Unique CharactersNot Completed

    Solutions: 464 | View all user solutions | Challenge discussion

    Bitmap HolesNot Completed

    Solutions: 329 | View all user solutions | Challenge discussion

    Symmetric TreeNot Completed

    Solutions: 295 | View all user solutions | Challenge discussion

    Binary Tree LCANot Completed

    Solutions: 160 | View all user solutions | Challenge discussion

    LRU CacheNot Completed

    Solutions: 196 | View all user solutions | Challenge discussion

    Tree ConstructorNot Completed

    Solutions: 300 | View all user solutions | Challenge discussion

    Array Min JumpsNot Completed

    Solutions: 232 | View all user solutions | Challenge discussion

    Nearest Smaller ValuesNot Completed

    Solutions: 424 | View all user solutions | Challenge discussion

    Matrix SpiralNot Completed

    Solutions: 201 | View all user solutions | Challenge discussion

    Word SplitNot Completed

    Solutions: 376 | View all user solutions | Challenge discussion

    Pair SearchingNot Completed

    Solutions: 126 | View all user solutions | Challenge discussion

    Boggle SolverNot Completed

    Solutions: 100 | View all user solutions | Challenge discussion

    HTML ElementsNot Completed

    Solutions: 163 | View all user solutions | Challenge discussion

    Missing Digit IINot Completed

    Solutions: 157 | View all user solutions | Challenge discussion

    Palindromic SubstringNot Completed

    Solutions: 263 | View all user solutions | Challenge discussion

    Trapping WaterNot Completed

    Solutions: 158 | View all user solutions | Challenge discussion

    Matrix PathNot Completed

    Solutions: 86 | View all user solutions | Challenge discussion

    Seating StudentsNot Completed

    Solutions: 157 | View all user solutions | Challenge discussion

    Longest Matrix PathNot Completed

    Solutions: 77 | View all user solutions | Challenge discussion

    Min Window SubstringNot Completed

    Solutions: 159 | View all user solutions | Challenge discussion

    Matrix ChainsNot Completed

    Solutions: 70 | View all user solutions | Challenge discussion

    Histogram AreaNot Completed

    Solutions: 122 | View all user solutions | Challenge discussion

    Matching CharactersNot Completed

    Solutions: 178 | View all user solutions | Challenge discussion

    Ternary ConverterNot Completed

    Solutions: 95 | View all user solutions | Challenge discussion

    Linear CongruenceNot Completed

    Solutions: 58 | View all user solutions | Challenge discussion

    Formatted NumberNot Completed

    Solutions: 202 | View all user solutions | Challenge discussion

    Largest Row ColumnNot Completed

    Solutions: 57 | View all user solutions | Challenge discussion

    Eight QueensNot Completed

    Solutions: 1220 | View all user solutions | Challenge discussion

    Three PointsNot Completed

    Solutions: 135 | View all user solutions | Challenge discussion

    Character RemovalNot Completed

    Solutions: 148 | View all user solutions | Challenge discussion

    Simple PasswordNot Completed

    Solutions: 199 | View all user solutions | Challenge discussion

    Preorder TraversalNot Completed

    Solutions: 92 | View all user solutions | Challenge discussion

    String ZigzagNot Completed

    Solutions: 101 | View all user solutions | Challenge discussion

    Off BinaryNot Completed

    Solutions: 85 | View all user solutions | Challenge discussion

    Longest ConsecutiveNot Completed

    Solutions: 305 | View all user solutions | Challenge discussion

    String ExpressionNot Completed

    Solutions: 143 | View all user solutions | Challenge discussion

    Charlie the DogNot Completed

    Solutions: 85 | View all user solutions | Challenge discussion

    Plus MinusNot Completed

    Solutions: 125 | View all user solutions | Challenge discussion

    PrimesNot Completed

    Solutions: 53 | View all user solutions | Challenge discussion

    String CalculateNot Completed

    Solutions: 20 | View all user solutions | Challenge discussion

    Hard Difficulty

    Sudoku Quadrant CheckerNot Completed

    Solutions: 134 | View all user solutions | Challenge discussion

    Optimal AssignmentsNot Completed

    Solutions: 528 | View all user solutions | Challenge discussion

    Transitivity RelationsNot Completed

    Solutions: 417 | View all user solutions | Challenge discussion

    Shortest PathNot Completed

    Solutions: 1184 | View all user solutions | Challenge discussion

    Polynomial ExpansionNot Completed

    Solutions: 298 | View all user solutions | Challenge discussion

    CalculatorNot Completed

    Solutions: 1169 | View all user solutions | Challenge discussion

    Pattern ChaserNot Completed

    Solutions: 767 | View all user solutions | Challenge discussion

    Weighted PathNot Completed

    Solutions: 366 | View all user solutions | Challenge discussion

    RREF MatrixNot Completed

    Solutions: 134 | View all user solutions | Challenge discussion

    Intersecting LinesNot Completed

    Solutions: 577 | View all user solutions | Challenge discussion

    Kaprekars ConstantNot Completed

    Solutions: 5405 | View all user solutions | Challenge discussion

    Hamiltonian PathNot Completed

    Solutions: 150 | View all user solutions | Challenge discussion

    Step WalkingNot Completed

    Solutions: 115 | View all user solutions | Challenge discussion

    Gas StationNot Completed

    Solutions: 589 | View all user solutions | Challenge discussion

    Symmetric MatrixNot Completed

    Solutions: 413 | View all user solutions | Challenge discussion

    Switch SortNot Completed

    Solutions: 289 | View all user solutions | Challenge discussion

    Matrix DeterminantNot Completed

    Solutions: 272 | View all user solutions | Challenge discussion

    Queen CheckNot Completed

    Solutions: 472 | View all user solutions | Challenge discussion

    Noughts DeterminerNot Completed

    Solutions: 383 | View all user solutions | Challenge discussion

    Blackjack HighestNot Completed

    Solutions: 535 | View all user solutions | Challenge discussion

    Alphabet Run EncryptionNot Completed

    Solutions: 249 | View all user solutions | Challenge discussion

    Vertex CoveringNot Completed

    Solutions: 146 | View all user solutions | Challenge discussion

    Knight JumpsNot Completed

    Solutions: 526 | View all user solutions | Challenge discussion

    Farthest NodesNot Completed

    Solutions: 156 | View all user solutions | Challenge discussion

    Line OrderingNot Completed

    Solutions: 73 | View all user solutions | Challenge discussion

    Quick KnightNot Completed

    Solutions: 66 | View all user solutions | Challenge discussion

    Square FiguresNot Completed

    Solutions: 158 | View all user solutions | Challenge discussion

    Connect Four WinnerNot Completed

    Solutions: 110 | View all user solutions | Challenge discussion

    Array JumpingNot Completed

    Solutions: 86 | View all user solutions | Challenge discussion

    Matrix BorderNot Completed

    Solutions: 83 | View all user solutions | Challenge discussion

    Roman Numeral ReductionNot Completed

    Solutions: 99 | View all user solutions | Challenge discussion

    Parallel SumsNot Completed

    Solutions: 158 | View all user solutions | Challenge discussion

    LCSNot Completed

    Solutions: 96 | View all user solutions | Challenge discussion

    Nim WinnerNot Completed

    Solutions: 60 | View all user solutions | Challenge discussion

    Pascals TriangleNot Completed

    Solutions: 116 | View all user solutions | Challenge discussion

    Reverse Polish NotationNot Completed

    Solutions: 222 | View all user solutions | Challenge discussion

    Max Heap CheckerNot Completed

    Solutions: 107 | View all user solutions | Challenge discussion

    Chessboard TravelingNot Completed

    Solutions: 2343 | View all user solutions | Challenge discussion

    Matching CouplesNot Completed

    Solutions: 125 | View all user solutions | Challenge discussion

    Approaching FibonacciNot Completed

    Solutions: 148 | View all user solutions | Challenge discussion

    Simple SATNot Completed

    Solutions: 81 | View all user solutions | Challenge discussion

    Array CouplesNot Completed

    Solutions: 118 | View all user solutions | Challenge discussion

    Bracket CombinationsNot Completed

    Solutions: 139 | View all user solutions | Challenge discussion

    Counting AnagramsNot Completed

    Solutions: 179 | View all user solutions | Challenge discussion

    Array RotationNot Completed

    Solutions: 188 | View all user solutions | Challenge discussion

    Maximal SquareNot Completed

    Solutions: 1497 | View all user solutions | Challenge discussion

    Maximal RectangleNot Completed

    Solutions: 48 | View all user solutions | Challenge discussion

    Bipartite MatchingNot Completed

    Solutions: 48 | View all user solutions | Challenge discussion

    Pentagonal NumberNot Completed

    Solutions: 1598 | View all user solutions | Challenge discussion

    City TrafficNot Completed

    Solutions: 50 | View all user solutions | Challenge discussion

    Convex Hull PointsNot Completed

    Solutions: 32 | View all user solutions | Challenge discussion

    Wildcard CharactersNot Completed

    Solutions: 83 | View all user solutions | Challenge discussion

    Tetris MoveNot Completed

    Solutions: 36 | View all user solutions | Challenge discussion

    WildcardsNot Completed

    Solutions: 26 | View all user solutions | Challenge discussion

    Difficulty

    Companies

    • Google 44
    • Facebook 23
    • Microsoft 21
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    Bootcamps

    • Hack Reactor 87
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    • optimization 22
    • matrix 21
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    • game 10
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    • sequences 7
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    • cache 1