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    Group TotalsNot Completed

    Solutions: 75 | View user solutions | Added 04/30/18

    Moving MedianNot Completed

    Solutions: 140 | View user solutions | Added 11/30/17

    Star RatingNot Completed

    Solutions: 363 | View user solutions | Added 10/30/17

    Free Challenges

    Longest WordNot Completed

    Solutions: 66248 | Step-by-step solution | Challenge discussion

    First FactorialNot Completed

    Solutions: 83996 | Step-by-step solution | Challenge discussion

    First ReverseNot Completed

    Solutions: 106507 | Step-by-step solution | Challenge discussion

    Letter ChangesNot Completed

    Solutions: 64165 | Step-by-step solution | Challenge discussion

    Simple AddingNot Completed

    Solutions: 52692 | Step-by-step solution | Challenge discussion

    Letter CapitalizeNot Completed

    Solutions: 44801 | Step-by-step solution | Challenge discussion

    Simple SymbolsNot Completed

    Solutions: 38058 | Step-by-step solution | Challenge discussion

    Check NumsNot Completed

    Solutions: 38619 | Step-by-step solution | Challenge discussion

    Time ConvertNot Completed

    Solutions: 29263 | Step-by-step solution | Challenge discussion

    Alphabet SoupNot Completed

    Solutions: 27065 | Step-by-step solution | Challenge discussion

    Kaprekars ConstantNot Completed

    Solutions: 3269 | View all user solutions | Challenge discussion

    Chessboard TravelingNot Completed

    Solutions: 1335 | View all user solutions | Challenge discussion

    Maximal SquareNot Completed

    Solutions: 878 | View all user solutions | Challenge discussion

    Pentagonal NumberNot Completed

    Solutions: 949 | View all user solutions | Challenge discussion

    Correct PathNot Completed

    Solutions: 1227 | View all user solutions | Challenge discussion

    Scale BalancingNot Completed

    Solutions: 1631 | View all user solutions | Challenge discussion

    Vowel SquareNot Completed

    Solutions: 1090 | View all user solutions | Challenge discussion

    Eight QueensNot Completed

    Solutions: 700 | View all user solutions | Challenge discussion

    Closest Enemy IINot Completed

    Solutions: 915 | View all user solutions | Challenge discussion

    Questions MarksNot Completed

    Solutions: 2628 | View all user solutions | Challenge discussion

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    Easy Difficulty

    First ReverseNot Completed

    Solutions: 106507 | Step-by-step solution | Challenge discussion

    First FactorialNot Completed

    Solutions: 83996 | Step-by-step solution | Challenge discussion

    Longest WordNot Completed

    Solutions: 66248 | Step-by-step solution | Challenge discussion

    Letter ChangesNot Completed

    Solutions: 64165 | Step-by-step solution | Challenge discussion

    Simple AddingNot Completed

    Solutions: 52692 | Step-by-step solution | Challenge discussion

    Letter CapitalizeNot Completed

    Solutions: 44801 | Step-by-step solution | Challenge discussion

    Simple SymbolsNot Completed

    Solutions: 38058 | Step-by-step solution | Challenge discussion

    Check NumsNot Completed

    Solutions: 38619 | Step-by-step solution | Challenge discussion

    Time ConvertNot Completed

    Solutions: 29263 | Step-by-step solution | Challenge discussion

    Alphabet SoupNot Completed

    Solutions: 27065 | Step-by-step solution | Challenge discussion

    AB CheckNot Completed

    Solutions: 16711 | Step-by-step solution | Challenge discussion

    Vowel CountNot Completed

    Solutions: 15406 | Step-by-step solution | Challenge discussion

    Word CountNot Completed

    Solutions: 14554 | Step-by-step solution | Challenge discussion

    Ex OhNot Completed

    Solutions: 14230 | Step-by-step solution | Challenge discussion

    PalindromeNot Completed

    Solutions: 16557 | Step-by-step solution | Challenge discussion

    Arith GeoNot Completed

    Solutions: 13196 | Step-by-step solution | Challenge discussion

    Array Addition INot Completed

    Solutions: 8421 | Step-by-step solution | Challenge discussion

    Letter Count INot Completed

    Solutions: 7726 | Step-by-step solution | Challenge discussion

    Second GreatLowNot Completed

    Solutions: 12845 | Step-by-step solution | Challenge discussion

    Division StringifiedNot Completed

    Solutions: 9632 | Step-by-step solution | Challenge discussion

    Counting Minutes INot Completed

    Solutions: 5695 | Step-by-step solution | Challenge discussion

    Mean ModeNot Completed

    Solutions: 7490 | Step-by-step solution | Challenge discussion

    Dash InsertNot Completed

    Solutions: 8474 | Step-by-step solution | Challenge discussion

    Swap CaseNot Completed

    Solutions: 8046 | Step-by-step solution | Challenge discussion

    Number AdditionNot Completed

    Solutions: 7896 | Step-by-step solution | Challenge discussion

    Third GreatestNot Completed

    Solutions: 7298 | Step-by-step solution | Challenge discussion

    Powers of TwoNot Completed

    Solutions: 8183 | Step-by-step solution | Challenge discussion

    Additive PersistenceNot Completed

    Solutions: 5824 | Step-by-step solution | Challenge discussion

    Multiplicative PersistenceNot Completed

    Solutions: 4495 | Step-by-step solution | Challenge discussion

    Off Line MinimumNot Completed

    Solutions: 6042 | Step-by-step solution | Challenge discussion

    Changing SequenceNot Completed

    Solutions: 2460 | Step-by-step solution | Challenge discussion

    Overlapping RangesNot Completed

    Solutions: 2464 | Step-by-step solution | Challenge discussion

    SuperincreasingNot Completed

    Solutions: 2509 | Step-by-step solution | Challenge discussion

    Hamming DistanceNot Completed

    Solutions: 1711 | Step-by-step solution | Challenge discussion

    Rectangle AreaNot Completed

    Solutions: 2079 | Step-by-step solution | Challenge discussion

    Bitwise OneNot Completed

    Solutions: 1697 | Step-by-step solution | Challenge discussion

    Other ProductsNot Completed

    Solutions: 1720 | Step-by-step solution | Challenge discussion

    Wave SortingNot Completed

    Solutions: 1190 | Step-by-step solution | Challenge discussion

    Array MatchingNot Completed

    Solutions: 1454 | Step-by-step solution | Challenge discussion

    Binary ReversalNot Completed

    Solutions: 1213 | Step-by-step solution | Challenge discussion

    Longest Increasing SequenceNot Completed

    Solutions: 1162 | Step-by-step solution | Challenge discussion

    Even PairsNot Completed

    Solutions: 1102 | Step-by-step solution | Challenge discussion

    Next PalindromeNot Completed

    Solutions: 968 | Step-by-step solution | Challenge discussion

    Largest PairNot Completed

    Solutions: 1299 | Step-by-step solution | Challenge discussion

    Nonrepeating CharacterNot Completed

    Solutions: 951 | Step-by-step solution | Challenge discussion

    Two SumNot Completed

    Solutions: 1757 | Step-by-step solution | Challenge discussion

    Bitwise TwoNot Completed

    Solutions: 696 | Step-by-step solution | Challenge discussion

    Power Set CountNot Completed

    Solutions: 1018 | Step-by-step solution | Challenge discussion

    Product DigitsNot Completed

    Solutions: 1280 | Step-by-step solution | Challenge discussion

    Palindrome CreatorNot Completed

    Solutions: 1035 | Step-by-step solution | Challenge discussion

    Basic Roman NumeralsNot Completed

    Solutions: 703 | Step-by-step solution | Challenge discussion

    Food DistributionNot Completed

    Solutions: 598 | Step-by-step solution | Challenge discussion

    Three SumNot Completed

    Solutions: 703 | Step-by-step solution | Challenge discussion

    Correct PathNot Completed

    Solutions: 1227 | Step-by-step solution | Challenge discussion

    Scale BalancingNot Completed

    Solutions: 1631 | Step-by-step solution | Challenge discussion

    Three NumbersNot Completed

    Solutions: 668 | Step-by-step solution | Challenge discussion

    Alphabet SearchingNot Completed

    Solutions: 570 | Step-by-step solution | Challenge discussion

    Time DifferenceNot Completed

    Solutions: 368 | Step-by-step solution | Challenge discussion

    Triangle RowNot Completed

    Solutions: 356 | Step-by-step solution | Challenge discussion

    Vowel SquareNot Completed

    Solutions: 1090 | Step-by-step solution | Challenge discussion

    Closest EnemyNot Completed

    Solutions: 523 | Step-by-step solution | Challenge discussion

    Closest Enemy IINot Completed

    Solutions: 915 | Step-by-step solution | Challenge discussion

    Number StreamNot Completed

    Solutions: 348 | Step-by-step solution | Challenge discussion

    Largest FourNot Completed

    Solutions: 525 | Step-by-step solution | Challenge discussion

    Distinct CharactersNot Completed

    Solutions: 379 | Step-by-step solution | Challenge discussion

    Questions MarksNot Completed

    Solutions: 2628 | Step-by-step solution | Challenge discussion

    Camel CaseNot Completed

    Solutions: 442 | Step-by-step solution | Challenge discussion

    ASCII ConversionNot Completed

    Solutions: 301 | Step-by-step solution | Challenge discussion

    Simple EvensNot Completed

    Solutions: 413 | Step-by-step solution | Challenge discussion

    Snake CaseNot Completed

    Solutions: 361 | Step-by-step solution | Challenge discussion

    Sum MultiplierNot Completed

    Solutions: 450 | Step-by-step solution | Challenge discussion

    String MergeNot Completed

    Solutions: 427 | Step-by-step solution | Challenge discussion

    One DecrementedNot Completed

    Solutions: 398 | Step-by-step solution | Challenge discussion

    Element MergerNot Completed

    Solutions: 432 | Step-by-step solution | Challenge discussion

    GCFNot Completed

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

    Serial NumberNot Completed

    Solutions: 556 | Step-by-step solution | Challenge discussion

    String PeriodsNot Completed

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

    Palindrome SwapperNot Completed

    Solutions: 275 | Step-by-step solution | Challenge discussion

    Remove BracketsNot Completed

    Solutions: 398 | Step-by-step solution | Challenge discussion

    Command LineNot Completed

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

    Star RatingNot Completed

    Solutions: 363 | Step-by-step solution | Challenge discussion

    Moving MedianNot Completed

    Solutions: 140 | Step-by-step solution | Challenge discussion

    Group TotalsNot Completed

    Solutions: 75 | Step-by-step solution | Challenge discussion

    Medium Difficulty

    Prime TimeNot Completed

    Solutions: 11936 | Step-by-step solution | Challenge discussion

    Run Length Not Completed

    Solutions: 8483 | Step-by-step solution | Challenge discussion

    Prime MoverNot Completed

    Solutions: 7385 | Step-by-step solution | Challenge discussion

    Palindrome TwoNot Completed

    Solutions: 7061 | Step-by-step solution | Challenge discussion

    DivisionNot Completed

    Solutions: 6582 | Step-by-step solution | Challenge discussion

    String ScrambleNot Completed

    Solutions: 7190 | Step-by-step solution | Challenge discussion

    Arith Geo IINot Completed

    Solutions: 4953 | Step-by-step solution | Challenge discussion

    Array AdditionNot Completed

    Solutions: 4342 | Step-by-step solution | Challenge discussion

    Binary ConverterNot Completed

    Solutions: 4482 | Step-by-step solution | Challenge discussion

    Letter CountNot Completed

    Solutions: 4430 | Step-by-step solution | Challenge discussion

    Simple ModeNot Completed

    Solutions: 4963 | Step-by-step solution | Challenge discussion

    Caesar CipherNot Completed

    Solutions: 5090 | Step-by-step solution | Challenge discussion

    Formatted DivisionNot Completed

    Solutions: 3755 | Step-by-step solution | Challenge discussion

    ConsecutiveNot Completed

    Solutions: 4064 | Step-by-step solution | Challenge discussion

    Counting MinutesNot Completed

    Solutions: 2758 | View all user solutions | Challenge discussion

    Permutation StepNot Completed

    Solutions: 3275 | View all user solutions | Challenge discussion

    Prime CheckerNot Completed

    Solutions: 2518 | View all user solutions | Challenge discussion

    Dash Insert IINot Completed

    Solutions: 4875 | View all user solutions | Challenge discussion

    Swap IINot Completed

    Solutions: 2710 | View all user solutions | Challenge discussion

    Number SearchNot Completed

    Solutions: 3322 | View all user solutions | Challenge discussion

    Triple DoubleNot Completed

    Solutions: 3094 | View all user solutions | Challenge discussion

    Bracket MatcherNot Completed

    Solutions: 2811 | View all user solutions | Challenge discussion

    String ReductionNot Completed

    Solutions: 2316 | View all user solutions | Challenge discussion

    Coin DeterminerNot Completed

    Solutions: 2282 | View all user solutions | Challenge discussion

    ThreeFive MultiplesNot Completed

    Solutions: 2812 | View all user solutions | Challenge discussion

    Fibonacci CheckerNot Completed

    Solutions: 2630 | View all user solutions | Challenge discussion

    Multiple BracketsNot Completed

    Solutions: 2325 | View all user solutions | Challenge discussion

    Most Free TimeNot Completed

    Solutions: 1400 | View all user solutions | Challenge discussion

    Overlapping RectanglesNot Completed

    Solutions: 1596 | View all user solutions | Challenge discussion

    Distinct ListNot Completed

    Solutions: 2383 | View all user solutions | Challenge discussion

    Look Say SequenceNot Completed

    Solutions: 1455 | View all user solutions | Challenge discussion

    Number EncodingNot Completed

    Solutions: 1476 | View all user solutions | Challenge discussion

    Stock PickerNot Completed

    Solutions: 722 | View all user solutions | Challenge discussion

    Max SubarrayNot Completed

    Solutions: 637 | View all user solutions | Challenge discussion

    Missing DigitNot Completed

    Solutions: 429 | View all user solutions | Challenge discussion

    K Unique CharactersNot Completed

    Solutions: 430 | View all user solutions | Challenge discussion

    Bitmap HolesNot Completed

    Solutions: 313 | View all user solutions | Challenge discussion

    Symmetric TreeNot Completed

    Solutions: 277 | View all user solutions | Challenge discussion

    Binary Search Tree LCANot Completed

    Solutions: 242 | View all user solutions | Challenge discussion

    Binary Tree LCANot Completed

    Solutions: 140 | View all user solutions | Challenge discussion

    LRU CacheNot Completed

    Solutions: 180 | View all user solutions | Challenge discussion

    Tree ConstructorNot Completed

    Solutions: 276 | View all user solutions | Challenge discussion

    Array Min JumpsNot Completed

    Solutions: 210 | View all user solutions | Challenge discussion

    Nearest Smaller ValuesNot Completed

    Solutions: 387 | View all user solutions | Challenge discussion

    Matrix SpiralNot Completed

    Solutions: 183 | View all user solutions | Challenge discussion

    Word SplitNot Completed

    Solutions: 348 | View all user solutions | Challenge discussion

    Pair SearchingNot Completed

    Solutions: 113 | View all user solutions | Challenge discussion

    Boggle SolverNot Completed

    Solutions: 88 | View all user solutions | Challenge discussion

    HTML ElementsNot Completed

    Solutions: 146 | View all user solutions | Challenge discussion

    Missing Digit IINot Completed

    Solutions: 147 | View all user solutions | Challenge discussion

    Palindromic SubstringNot Completed

    Solutions: 254 | View all user solutions | Challenge discussion

    Trapping WaterNot Completed

    Solutions: 144 | View all user solutions | Challenge discussion

    Matrix PathNot Completed

    Solutions: 72 | View all user solutions | Challenge discussion

    Seating StudentsNot Completed

    Solutions: 145 | View all user solutions | Challenge discussion

    Longest Matrix PathNot Completed

    Solutions: 61 | View all user solutions | Challenge discussion

    Min Window SubstringNot Completed

    Solutions: 148 | View all user solutions | Challenge discussion

    Matrix ChainsNot Completed

    Solutions: 63 | View all user solutions | Challenge discussion

    Histogram AreaNot Completed

    Solutions: 113 | View all user solutions | Challenge discussion

    Matching CharactersNot Completed

    Solutions: 158 | View all user solutions | Challenge discussion

    Ternary ConverterNot Completed

    Solutions: 87 | View all user solutions | Challenge discussion

    Linear CongruenceNot Completed

    Solutions: 46 | View all user solutions | Challenge discussion

    Formatted NumberNot Completed

    Solutions: 181 | View all user solutions | Challenge discussion

    Largest Row ColumnNot Completed

    Solutions: 50 | View all user solutions | Challenge discussion

    Eight QueensNot Completed

    Solutions: 700 | View all user solutions | Challenge discussion

    Three PointsNot Completed

    Solutions: 113 | View all user solutions | Challenge discussion

    Character RemovalNot Completed

    Solutions: 136 | View all user solutions | Challenge discussion

    Simple PasswordNot Completed

    Solutions: 177 | View all user solutions | Challenge discussion

    Preorder TraversalNot Completed

    Solutions: 76 | View all user solutions | Challenge discussion

    String ZigzagNot Completed

    Solutions: 88 | View all user solutions | Challenge discussion

    Off BinaryNot Completed

    Solutions: 79 | View all user solutions | Challenge discussion

    Longest ConsecutiveNot Completed

    Solutions: 284 | View all user solutions | Challenge discussion

    String ExpressionNot Completed

    Solutions: 131 | View all user solutions | Challenge discussion

    Charlie the DogNot Completed

    Solutions: 67 | View all user solutions | Challenge discussion

    Plus MinusNot Completed

    Solutions: 111 | View all user solutions | Challenge discussion

    Hard Difficulty

    Shortest PathNot Completed

    Solutions: 1144 | View all user solutions | Challenge discussion

    Pattern ChaserNot Completed

    Solutions: 755 | View all user solutions | Challenge discussion

    CalculatorNot Completed

    Solutions: 1158 | View all user solutions | Challenge discussion

    Weighted PathNot Completed

    Solutions: 359 | View all user solutions | Challenge discussion

    Intersecting LinesNot Completed

    Solutions: 564 | View all user solutions | Challenge discussion

    RREF MatrixNot Completed

    Solutions: 123 | View all user solutions | Challenge discussion

    Polynomial ExpansionNot Completed

    Solutions: 289 | View all user solutions | Challenge discussion

    Gas StationNot Completed

    Solutions: 577 | View all user solutions | Challenge discussion

    Symmetric MatrixNot Completed

    Solutions: 405 | View all user solutions | Challenge discussion

    Switch SortNot Completed

    Solutions: 282 | View all user solutions | Challenge discussion

    Matrix DeterminantNot Completed

    Solutions: 264 | View all user solutions | Challenge discussion

    Queen CheckNot Completed

    Solutions: 466 | View all user solutions | Challenge discussion

    Noughts DeterminerNot Completed

    Solutions: 379 | View all user solutions | Challenge discussion

    Blackjack HighestNot Completed

    Solutions: 521 | View all user solutions | Challenge discussion

    Transitivity RelationsNot Completed

    Solutions: 411 | View all user solutions | Challenge discussion

    Alphabet Run EncryptionNot Completed

    Solutions: 245 | View all user solutions | Challenge discussion

    Knight JumpsNot Completed

    Solutions: 522 | View all user solutions | Challenge discussion

    Line OrderingNot Completed

    Solutions: 64 | View all user solutions | Challenge discussion

    Sudoku Quadrant CheckerNot Completed

    Solutions: 107 | View all user solutions | Challenge discussion

    Quick KnightNot Completed

    Solutions: 58 | View all user solutions | Challenge discussion

    Square FiguresNot Completed

    Solutions: 147 | View all user solutions | Challenge discussion

    Connect Four WinnerNot Completed

    Solutions: 107 | View all user solutions | Challenge discussion

    Array JumpingNot Completed

    Solutions: 77 | View all user solutions | Challenge discussion

    Matrix BorderNot Completed

    Solutions: 65 | View all user solutions | Challenge discussion

    Roman Numeral ReductionNot Completed

    Solutions: 92 | View all user solutions | Challenge discussion

    Parallel SumsNot Completed

    Solutions: 145 | View all user solutions | Challenge discussion

    LCSNot Completed

    Solutions: 83 | View all user solutions | Challenge discussion

    Nim WinnerNot Completed

    Solutions: 51 | View all user solutions | Challenge discussion

    Farthest NodesNot Completed

    Solutions: 149 | View all user solutions | Challenge discussion

    Optimal AssignmentsNot Completed

    Solutions: 507 | View all user solutions | Challenge discussion

    Kaprekars ConstantNot Completed

    Solutions: 3269 | View all user solutions | Challenge discussion

    Hamiltonian PathNot Completed

    Solutions: 140 | View all user solutions | Challenge discussion

    Vertex CoveringNot Completed

    Solutions: 138 | View all user solutions | Challenge discussion

    Step WalkingNot Completed

    Solutions: 104 | View all user solutions | Challenge discussion

    Pascals TriangleNot Completed

    Solutions: 110 | View all user solutions | Challenge discussion

    Reverse Polish NotationNot Completed

    Solutions: 218 | View all user solutions | Challenge discussion

    Max Heap CheckerNot Completed

    Solutions: 101 | View all user solutions | Challenge discussion

    Chessboard TravelingNot Completed

    Solutions: 1335 | View all user solutions | Challenge discussion

    Matching CouplesNot Completed

    Solutions: 118 | View all user solutions | Challenge discussion

    Approaching FibonacciNot Completed

    Solutions: 137 | View all user solutions | Challenge discussion

    Simple SATNot Completed

    Solutions: 73 | View all user solutions | Challenge discussion

    Array CouplesNot Completed

    Solutions: 111 | View all user solutions | Challenge discussion

    Array RotationNot Completed

    Solutions: 171 | View all user solutions | Challenge discussion

    Bracket CombinationsNot Completed

    Solutions: 130 | View all user solutions | Challenge discussion

    Counting AnagramsNot Completed

    Solutions: 161 | View all user solutions | Challenge discussion

    Maximal SquareNot Completed

    Solutions: 878 | View all user solutions | Challenge discussion

    Maximal RectangleNot Completed

    Solutions: 41 | View all user solutions | Challenge discussion

    Bipartite MatchingNot Completed

    Solutions: 41 | View all user solutions | Challenge discussion

    Pentagonal NumberNot Completed

    Solutions: 949 | View all user solutions | Challenge discussion

    City TrafficNot Completed

    Solutions: 42 | View all user solutions | Challenge discussion

    Convex Hull PointsNot Completed

    Solutions: 28 | View all user solutions | Challenge discussion

    Wildcard CharactersNot Completed

    Solutions: 71 | View all user solutions | Challenge discussion

    Tetris MoveNot Completed

    Solutions: 18 | View all user solutions | Challenge discussion

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