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    Moving MedianNot Completed

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    Star RatingNot Completed

    Solutions: 239 | View user solutions | Added 10/30/17

    Command LineNot Completed

    Solutions: 88 | View user solutions | Added 10/28/17

    Free Challenges

    Longest WordNot Completed

    Solutions: 54977 | Step-by-step solution | Challenge discussion

    First FactorialNot Completed

    Solutions: 71000 | Step-by-step solution | Challenge discussion

    First ReverseNot Completed

    Solutions: 95321 | Step-by-step solution | Challenge discussion

    Letter ChangesNot Completed

    Solutions: 55549 | Step-by-step solution | Challenge discussion

    Simple AddingNot Completed

    Solutions: 45722 | Step-by-step solution | Challenge discussion

    Letter CapitalizeNot Completed

    Solutions: 38941 | Step-by-step solution | Challenge discussion

    Simple SymbolsNot Completed

    Solutions: 32347 | Step-by-step solution | Challenge discussion

    Check NumsNot Completed

    Solutions: 33258 | Step-by-step solution | Challenge discussion

    Time ConvertNot Completed

    Solutions: 25140 | Step-by-step solution | Challenge discussion

    Alphabet SoupNot Completed

    Solutions: 23419 | Step-by-step solution | Challenge discussion

    Kaprekars ConstantNot Completed

    Solutions: 1480 | View all user solutions | Challenge discussion

    Chessboard TravelingNot Completed

    Solutions: 574 | View all user solutions | Challenge discussion

    Maximal SquareNot Completed

    Solutions: 407 | View all user solutions | Challenge discussion

    Pentagonal NumberNot Completed

    Solutions: 420 | View all user solutions | Challenge discussion

    Correct PathNot Completed

    Solutions: 888 | View all user solutions | Challenge discussion

    Scale BalancingNot Completed

    Solutions: 1143 | View all user solutions | Challenge discussion

    Vowel SquareNot Completed

    Solutions: 731 | View all user solutions | Challenge discussion

    Eight QueensNot Completed

    Solutions: 372 | View all user solutions | Challenge discussion

    Closest Enemy IINot Completed

    Solutions: 570 | View all user solutions | Challenge discussion

    Questions MarksNot Completed

    Solutions: 1543 | View all user solutions | Challenge discussion

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    Easy Difficulty

    First ReverseNot Completed

    Solutions: 95321 | Step-by-step solution | Challenge discussion

    First FactorialNot Completed

    Solutions: 71000 | Step-by-step solution | Challenge discussion

    Longest WordNot Completed

    Solutions: 54977 | Step-by-step solution | Challenge discussion

    Letter ChangesNot Completed

    Solutions: 55549 | Step-by-step solution | Challenge discussion

    Simple AddingNot Completed

    Solutions: 45722 | Step-by-step solution | Challenge discussion

    Letter CapitalizeNot Completed

    Solutions: 38941 | Step-by-step solution | Challenge discussion

    Simple SymbolsNot Completed

    Solutions: 32347 | Step-by-step solution | Challenge discussion

    Check NumsNot Completed

    Solutions: 33258 | Step-by-step solution | Challenge discussion

    Time ConvertNot Completed

    Solutions: 25140 | Step-by-step solution | Challenge discussion

    Alphabet SoupNot Completed

    Solutions: 23419 | Step-by-step solution | Challenge discussion

    AB CheckNot Completed

    Solutions: 16264 | Step-by-step solution | Challenge discussion

    Vowel CountNot Completed

    Solutions: 15088 | Step-by-step solution | Challenge discussion

    Word CountNot Completed

    Solutions: 14254 | Step-by-step solution | Challenge discussion

    Ex OhNot Completed

    Solutions: 13895 | Step-by-step solution | Challenge discussion

    PalindromeNot Completed

    Solutions: 16167 | Step-by-step solution | Challenge discussion

    Arith GeoNot Completed

    Solutions: 12876 | Step-by-step solution | Challenge discussion

    Array Addition INot Completed

    Solutions: 8152 | Step-by-step solution | Challenge discussion

    Letter Count INot Completed

    Solutions: 7464 | Step-by-step solution | Challenge discussion

    Second GreatLowNot Completed

    Solutions: 12450 | Step-by-step solution | Challenge discussion

    Division StringifiedNot Completed

    Solutions: 9338 | Step-by-step solution | Challenge discussion

    Counting Minutes INot Completed

    Solutions: 5522 | Step-by-step solution | Challenge discussion

    Mean ModeNot Completed

    Solutions: 7303 | Step-by-step solution | Challenge discussion

    Dash InsertNot Completed

    Solutions: 8258 | Step-by-step solution | Challenge discussion

    Swap CaseNot Completed

    Solutions: 7858 | Step-by-step solution | Challenge discussion

    Number AdditionNot Completed

    Solutions: 7673 | Step-by-step solution | Challenge discussion

    Third GreatestNot Completed

    Solutions: 7090 | Step-by-step solution | Challenge discussion

    Powers of TwoNot Completed

    Solutions: 7991 | Step-by-step solution | Challenge discussion

    Additive PersistenceNot Completed

    Solutions: 5628 | Step-by-step solution | Challenge discussion

    Multiplicative PersistenceNot Completed

    Solutions: 4357 | Step-by-step solution | Challenge discussion

    Off Line MinimumNot Completed

    Solutions: 5834 | Step-by-step solution | Challenge discussion

    Changing SequenceNot Completed

    Solutions: 2281 | Step-by-step solution | Challenge discussion

    Overlapping RangesNot Completed

    Solutions: 2297 | Step-by-step solution | Challenge discussion

    SuperincreasingNot Completed

    Solutions: 2324 | Step-by-step solution | Challenge discussion

    Hamming DistanceNot Completed

    Solutions: 1567 | Step-by-step solution | Challenge discussion

    Rectangle AreaNot Completed

    Solutions: 1909 | Step-by-step solution | Challenge discussion

    Bitwise OneNot Completed

    Solutions: 1559 | Step-by-step solution | Challenge discussion

    Other ProductsNot Completed

    Solutions: 1569 | Step-by-step solution | Challenge discussion

    Wave SortingNot Completed

    Solutions: 1044 | Step-by-step solution | Challenge discussion

    Array MatchingNot Completed

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

    Binary ReversalNot Completed

    Solutions: 1067 | Step-by-step solution | Challenge discussion

    Longest Increasing SequenceNot Completed

    Solutions: 1007 | Step-by-step solution | Challenge discussion

    Even PairsNot Completed

    Solutions: 960 | Step-by-step solution | Challenge discussion

    Next PalindromeNot Completed

    Solutions: 847 | Step-by-step solution | Challenge discussion

    Largest PairNot Completed

    Solutions: 1191 | Step-by-step solution | Challenge discussion

    Nonrepeating CharacterNot Completed

    Solutions: 849 | Step-by-step solution | Challenge discussion

    Two SumNot Completed

    Solutions: 1554 | Step-by-step solution | Challenge discussion

    Bitwise TwoNot Completed

    Solutions: 599 | Step-by-step solution | Challenge discussion

    Power Set CountNot Completed

    Solutions: 890 | Step-by-step solution | Challenge discussion

    Product DigitsNot Completed

    Solutions: 1158 | Step-by-step solution | Challenge discussion

    Palindrome CreatorNot Completed

    Solutions: 919 | Step-by-step solution | Challenge discussion

    Basic Roman NumeralsNot Completed

    Solutions: 634 | Step-by-step solution | Challenge discussion

    Food DistributionNot Completed

    Solutions: 511 | Step-by-step solution | Challenge discussion

    Three SumNot Completed

    Solutions: 613 | Step-by-step solution | Challenge discussion

    Correct PathNot Completed

    Solutions: 888 | Step-by-step solution | Challenge discussion

    Scale BalancingNot Completed

    Solutions: 1143 | Step-by-step solution | Challenge discussion

    Three NumbersNot Completed

    Solutions: 575 | Step-by-step solution | Challenge discussion

    Alphabet SearchingNot Completed

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

    Time DifferenceNot Completed

    Solutions: 313 | Step-by-step solution | Challenge discussion

    Triangle RowNot Completed

    Solutions: 298 | Step-by-step solution | Challenge discussion

    Vowel SquareNot Completed

    Solutions: 731 | Step-by-step solution | Challenge discussion

    Closest EnemyNot Completed

    Solutions: 451 | Step-by-step solution | Challenge discussion

    Closest Enemy IINot Completed

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

    Number StreamNot Completed

    Solutions: 268 | Step-by-step solution | Challenge discussion

    Largest FourNot Completed

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

    Distinct CharactersNot Completed

    Solutions: 307 | Step-by-step solution | Challenge discussion

    Questions MarksNot Completed

    Solutions: 1543 | Step-by-step solution | Challenge discussion

    Camel CaseNot Completed

    Solutions: 360 | Step-by-step solution | Challenge discussion

    ASCII ConversionNot Completed

    Solutions: 239 | Step-by-step solution | Challenge discussion

    Simple EvensNot Completed

    Solutions: 340 | Step-by-step solution | Challenge discussion

    Snake CaseNot Completed

    Solutions: 298 | Step-by-step solution | Challenge discussion

    Sum MultiplierNot Completed

    Solutions: 386 | Step-by-step solution | Challenge discussion

    String MergeNot Completed

    Solutions: 355 | Step-by-step solution | Challenge discussion

    One DecrementedNot Completed

    Solutions: 342 | Step-by-step solution | Challenge discussion

    Element MergerNot Completed

    Solutions: 367 | Step-by-step solution | Challenge discussion

    GCFNot Completed

    Solutions: 335 | Step-by-step solution | Challenge discussion

    Serial NumberNot Completed

    Solutions: 345 | Step-by-step solution | Challenge discussion

    String PeriodsNot Completed

    Solutions: 306 | Step-by-step solution | Challenge discussion

    Palindrome SwapperNot Completed

    Solutions: 217 | Step-by-step solution | Challenge discussion

    Remove BracketsNot Completed

    Solutions: 309 | Step-by-step solution | Challenge discussion

    Command LineNot Completed

    Solutions: 88 | Step-by-step solution | Challenge discussion

    Star RatingNot Completed

    Solutions: 239 | Step-by-step solution | Challenge discussion

    Moving MedianNot Completed

    Solutions: 70 | Step-by-step solution | Challenge discussion

    Medium Difficulty

    Prime TimeNot Completed

    Solutions: 11745 | Step-by-step solution | Challenge discussion

    Run Length Not Completed

    Solutions: 8292 | Step-by-step solution | Challenge discussion

    Prime MoverNot Completed

    Solutions: 7252 | Step-by-step solution | Challenge discussion

    Palindrome TwoNot Completed

    Solutions: 6904 | Step-by-step solution | Challenge discussion

    DivisionNot Completed

    Solutions: 6462 | Step-by-step solution | Challenge discussion

    String ScrambleNot Completed

    Solutions: 7036 | Step-by-step solution | Challenge discussion

    Arith Geo IINot Completed

    Solutions: 4864 | Step-by-step solution | Challenge discussion

    Array AdditionNot Completed

    Solutions: 4199 | Step-by-step solution | Challenge discussion

    Binary ConverterNot Completed

    Solutions: 4413 | Step-by-step solution | Challenge discussion

    Letter CountNot Completed

    Solutions: 4326 | Step-by-step solution | Challenge discussion

    Simple ModeNot Completed

    Solutions: 4863 | Step-by-step solution | Challenge discussion

    Caesar CipherNot Completed

    Solutions: 4952 | Step-by-step solution | Challenge discussion

    Formatted DivisionNot Completed

    Solutions: 3658 | Step-by-step solution | Challenge discussion

    ConsecutiveNot Completed

    Solutions: 3977 | Step-by-step solution | Challenge discussion

    Counting MinutesNot Completed

    Solutions: 2686 | View all user solutions | Challenge discussion

    Permutation StepNot Completed

    Solutions: 3189 | View all user solutions | Challenge discussion

    Prime CheckerNot Completed

    Solutions: 2459 | View all user solutions | Challenge discussion

    Dash Insert IINot Completed

    Solutions: 4784 | View all user solutions | Challenge discussion

    Swap IINot Completed

    Solutions: 2652 | View all user solutions | Challenge discussion

    Number SearchNot Completed

    Solutions: 3254 | View all user solutions | Challenge discussion

    Triple DoubleNot Completed

    Solutions: 3024 | View all user solutions | Challenge discussion

    Bracket MatcherNot Completed

    Solutions: 2755 | View all user solutions | Challenge discussion

    String ReductionNot Completed

    Solutions: 2266 | View all user solutions | Challenge discussion

    Coin DeterminerNot Completed

    Solutions: 2243 | View all user solutions | Challenge discussion

    ThreeFive MultiplesNot Completed

    Solutions: 2756 | View all user solutions | Challenge discussion

    Fibonacci CheckerNot Completed

    Solutions: 2572 | View all user solutions | Challenge discussion

    Multiple BracketsNot Completed

    Solutions: 2273 | View all user solutions | Challenge discussion

    Most Free TimeNot Completed

    Solutions: 1366 | View all user solutions | Challenge discussion

    Overlapping RectanglesNot Completed

    Solutions: 1535 | View all user solutions | Challenge discussion

    Distinct ListNot Completed

    Solutions: 2335 | View all user solutions | Challenge discussion

    Look Say SequenceNot Completed

    Solutions: 1403 | View all user solutions | Challenge discussion

    Number EncodingNot Completed

    Solutions: 1439 | View all user solutions | Challenge discussion

    Stock PickerNot Completed

    Solutions: 680 | View all user solutions | Challenge discussion

    Max SubarrayNot Completed

    Solutions: 593 | View all user solutions | Challenge discussion

    Missing DigitNot Completed

    Solutions: 400 | View all user solutions | Challenge discussion

    K Unique CharactersNot Completed

    Solutions: 389 | View all user solutions | Challenge discussion

    Bitmap HolesNot Completed

    Solutions: 272 | View all user solutions | Challenge discussion

    Symmetric TreeNot Completed

    Solutions: 243 | View all user solutions | Challenge discussion

    Binary Search Tree LCANot Completed

    Solutions: 214 | View all user solutions | Challenge discussion

    Binary Tree LCANot Completed

    Solutions: 121 | View all user solutions | Challenge discussion

    LRU CacheNot Completed

    Solutions: 160 | View all user solutions | Challenge discussion

    Tree ConstructorNot Completed

    Solutions: 149 | View all user solutions | Challenge discussion

    Array Min JumpsNot Completed

    Solutions: 196 | View all user solutions | Challenge discussion

    Nearest Smaller ValuesNot Completed

    Solutions: 363 | View all user solutions | Challenge discussion

    Matrix SpiralNot Completed

    Solutions: 158 | View all user solutions | Challenge discussion

    Word SplitNot Completed

    Solutions: 311 | View all user solutions | Challenge discussion

    Pair SearchingNot Completed

    Solutions: 96 | View all user solutions | Challenge discussion

    Boggle SolverNot Completed

    Solutions: 72 | View all user solutions | Challenge discussion

    HTML ElementsNot Completed

    Solutions: 130 | View all user solutions | Challenge discussion

    Missing Digit IINot Completed

    Solutions: 127 | View all user solutions | Challenge discussion

    Palindromic SubstringNot Completed

    Solutions: 216 | View all user solutions | Challenge discussion

    Trapping WaterNot Completed

    Solutions: 127 | View all user solutions | Challenge discussion

    Matrix PathNot Completed

    Solutions: 66 | View all user solutions | Challenge discussion

    Seating StudentsNot Completed

    Solutions: 121 | View all user solutions | Challenge discussion

    Longest Matrix PathNot Completed

    Solutions: 51 | View all user solutions | Challenge discussion

    Min Window SubstringNot Completed

    Solutions: 123 | View all user solutions | Challenge discussion

    Matrix ChainsNot Completed

    Solutions: 56 | View all user solutions | Challenge discussion

    Histogram AreaNot Completed

    Solutions: 92 | View all user solutions | Challenge discussion

    Matching CharactersNot Completed

    Solutions: 135 | View all user solutions | Challenge discussion

    Ternary ConverterNot Completed

    Solutions: 70 | View all user solutions | Challenge discussion

    Linear CongruenceNot Completed

    Solutions: 39 | View all user solutions | Challenge discussion

    Formatted NumberNot Completed

    Solutions: 149 | View all user solutions | Challenge discussion

    Largest Row ColumnNot Completed

    Solutions: 41 | View all user solutions | Challenge discussion

    Eight QueensNot Completed

    Solutions: 372 | View all user solutions | Challenge discussion

    Three PointsNot Completed

    Solutions: 91 | View all user solutions | Challenge discussion

    Character RemovalNot Completed

    Solutions: 117 | View all user solutions | Challenge discussion

    Simple PasswordNot Completed

    Solutions: 156 | View all user solutions | Challenge discussion

    Preorder TraversalNot Completed

    Solutions: 61 | View all user solutions | Challenge discussion

    String ZigzagNot Completed

    Solutions: 79 | View all user solutions | Challenge discussion

    Off BinaryNot Completed

    Solutions: 68 | View all user solutions | Challenge discussion

    Longest ConsecutiveNot Completed

    Solutions: 238 | View all user solutions | Challenge discussion

    String ExpressionNot Completed

    Solutions: 113 | View all user solutions | Challenge discussion

    Charlie the DogNot Completed

    Solutions: 50 | View all user solutions | Challenge discussion

    Plus MinusNot Completed

    Solutions: 82 | View all user solutions | Challenge discussion

    Hard Difficulty

    Shortest PathNot Completed

    Solutions: 1092 | View all user solutions | Challenge discussion

    Pattern ChaserNot Completed

    Solutions: 718 | View all user solutions | Challenge discussion

    CalculatorNot Completed

    Solutions: 1130 | View all user solutions | Challenge discussion

    Weighted PathNot Completed

    Solutions: 346 | View all user solutions | Challenge discussion

    Intersecting LinesNot Completed

    Solutions: 547 | View all user solutions | Challenge discussion

    RREF MatrixNot Completed

    Solutions: 122 | View all user solutions | Challenge discussion

    Polynomial ExpansionNot Completed

    Solutions: 281 | View all user solutions | Challenge discussion

    Gas StationNot Completed

    Solutions: 554 | View all user solutions | Challenge discussion

    Symmetric MatrixNot Completed

    Solutions: 392 | View all user solutions | Challenge discussion

    Switch SortNot Completed

    Solutions: 270 | View all user solutions | Challenge discussion

    Matrix DeterminantNot Completed

    Solutions: 256 | View all user solutions | Challenge discussion

    Queen CheckNot Completed

    Solutions: 451 | View all user solutions | Challenge discussion

    Noughts DeterminerNot Completed

    Solutions: 370 | View all user solutions | Challenge discussion

    Blackjack HighestNot Completed

    Solutions: 513 | View all user solutions | Challenge discussion

    Transitivity RelationsNot Completed

    Solutions: 408 | View all user solutions | Challenge discussion

    Alphabet Run EncryptionNot Completed

    Solutions: 240 | View all user solutions | Challenge discussion

    Knight JumpsNot Completed

    Solutions: 510 | View all user solutions | Challenge discussion

    Line OrderingNot Completed

    Solutions: 55 | View all user solutions | Challenge discussion

    Sudoku Quadrant CheckerNot Completed

    Solutions: 99 | View all user solutions | Challenge discussion

    Quick KnightNot Completed

    Solutions: 54 | View all user solutions | Challenge discussion

    Square FiguresNot Completed

    Solutions: 136 | View all user solutions | Challenge discussion

    Connect Four WinnerNot Completed

    Solutions: 87 | View all user solutions | Challenge discussion

    Array JumpingNot Completed

    Solutions: 65 | View all user solutions | Challenge discussion

    Matrix BorderNot Completed

    Solutions: 61 | View all user solutions | Challenge discussion

    Roman Numeral ReductionNot Completed

    Solutions: 77 | View all user solutions | Challenge discussion

    Parallel SumsNot Completed

    Solutions: 126 | View all user solutions | Challenge discussion

    LCSNot Completed

    Solutions: 71 | View all user solutions | Challenge discussion

    Nim WinnerNot Completed

    Solutions: 47 | View all user solutions | Challenge discussion

    Farthest NodesNot Completed

    Solutions: 141 | View all user solutions | Challenge discussion

    Optimal AssignmentsNot Completed

    Solutions: 496 | View all user solutions | Challenge discussion

    Kaprekars ConstantNot Completed

    Solutions: 1480 | View all user solutions | Challenge discussion

    Hamiltonian PathNot Completed

    Solutions: 134 | View all user solutions | Challenge discussion

    Vertex CoveringNot Completed

    Solutions: 134 | View all user solutions | Challenge discussion

    Step WalkingNot Completed

    Solutions: 96 | View all user solutions | Challenge discussion

    Pascals TriangleNot Completed

    Solutions: 91 | View all user solutions | Challenge discussion

    Reverse Polish NotationNot Completed

    Solutions: 209 | View all user solutions | Challenge discussion

    Max Heap CheckerNot Completed

    Solutions: 94 | View all user solutions | Challenge discussion

    Chessboard TravelingNot Completed

    Solutions: 574 | View all user solutions | Challenge discussion

    Matching CouplesNot Completed

    Solutions: 104 | View all user solutions | Challenge discussion

    Approaching FibonacciNot Completed

    Solutions: 128 | View all user solutions | Challenge discussion

    Simple SATNot Completed

    Solutions: 65 | View all user solutions | Challenge discussion

    Array CouplesNot Completed

    Solutions: 105 | View all user solutions | Challenge discussion

    Array RotationNot Completed

    Solutions: 164 | View all user solutions | Challenge discussion

    Bracket CombinationsNot Completed

    Solutions: 115 | View all user solutions | Challenge discussion

    Counting AnagramsNot Completed

    Solutions: 142 | View all user solutions | Challenge discussion

    Maximal SquareNot Completed

    Solutions: 407 | View all user solutions | Challenge discussion

    Maximal RectangleNot Completed

    Solutions: 33 | View all user solutions | Challenge discussion

    Bipartite MatchingNot Completed

    Solutions: 31 | View all user solutions | Challenge discussion

    Pentagonal NumberNot Completed

    Solutions: 420 | View all user solutions | Challenge discussion

    City TrafficNot Completed

    Solutions: 30 | View all user solutions | Challenge discussion

    Convex Hull PointsNot Completed

    Solutions: 26 | View all user solutions | Challenge discussion

    Wildcard CharactersNot Completed

    Solutions: 54 | View all user solutions | Challenge discussion

    Tetris MoveNot Completed

    Solutions: 15 | View all user solutions | Challenge discussion

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