Practice · judged on hidden tests

Problems

100 problems, ordered so each topic builds on the last.

Not startedThe longest path anywhere in the treeTreesMedium
Not startedThe longest run of ones, with k flipsSliding window, ArraysMedium
Not startedThe next bigger number to the rightStacks and queues, ArraysEasy
Not startedThe number more than halfArrays, Hash mapsEasy
Not startedThe number that appears onceBit manipulation, Arrays, Hash mapsEasy
Not startedThe one number that is not repeated three timesBit manipulation, ArraysMedium
Not startedThe slowest speed that still finishes in timeArrays, Binary searchMedium
Not startedThe smallest ship that still finishes in timeArrays, Binary searchMedium
Not startedThe smallest value after a rotationArrays, Binary searchMedium
Not startedThe widest, deepest containerArrays, Greedy, Two pointersMedium
Not startedTurn the digits aroundNumbers, BasicsEasy
Not startedTurn the list aroundLinked listsEasy
Not startedTurn the square a quarter turnMatrices, ArraysMedium
Not startedTwo baskets, one row of treesSliding window, Arrays, Hash mapsMedium
Not startedTwo sumArrays, Hash mapsEasy
Not startedTwo sum in a sorted listArrays, Binary search, Two pointersEasy
Not startedValid anagramStrings, Hash maps, SortingEasy
Not startedValid parenthesesStacks and queues, StringsEasy
Not startedWater held between the barsStacks and queues, Arrays, Two pointersHard
Not startedWhat the tree looks like from the rightStacks and queues, TreesMedium
Not startedWhat two lists have in commonHash sets, ArraysEasy
Not startedWhere a repeated value starts and endsArrays, Binary searchMedium
Not startedWhere the loop beginsLinked lists, Two pointersMedium
Not startedWord search IIBacktracking, Graphs, TriesHard
Not startedZip two sorted lists togetherLinked listsEasy