Practice · judged on hidden tests
Problems
100 problems, ordered so each topic builds on the last.
- Not startedA cache that forgets what you have not usedDesign, Linked lists, Hash mapsMedium
- Not startedAn order you can actually take the courses inTopological sort, GraphsMedium
- Not startedAre these two trees identicalTreesEasy
- Not startedArithmetic without bracketsStrings, Stacks and queuesMedium
- Not startedBest day to buy and sellDynamic programming, ArraysEasy
- Not startedBest run after k changesStrings, Sliding windowMedium
- Not startedBinary search on a sorted list someone rotatedArrays, Binary searchMedium
- Not startedBlank out every row and column holding a zeroMatrices, ArraysMedium
- Not startedBreak the loop and leave the listTwo pointers, Linked listsMedium
- Not startedBuilding Pascal's triangle row by rowDynamic programming, Basics, ArraysEasy
- Not startedCancel out neighbouring pairsStrings, Stacks and queuesEasy
- Not startedCan it be split into two equal halvesDynamic programming, ArraysMedium
- Not startedCan you get to the endGreedy, ArraysMedium
- Not startedCombine the ranges that overlapGreedy, Arrays, SortingMedium
- Not startedContains duplicateArrays, Hash setsEasy
- Not startedCount the islandsMatrices, GraphsMedium
- Not startedCourse scheduleTopological sort, GraphsMedium
- Not startedDoes this list loop back on itselfTwo pointers, Linked listsEasy
- Not startedDrop the nth node from the endTwo pointers, Linked listsMedium
- Not startedEvery arrangement of the letters, each one onceStrings, BacktrackingMedium
- Not startedEvery subset, in orderArrays, BacktrackingMedium
- Not startedEvery way the brackets can balanceStrings, BacktrackingMedium
- Not startedEvery way to make the targetArrays, BacktrackingMedium
- Not startedFewest coins to make the amountDynamic programming, GreedyMedium
- Not startedFind it by halvingArrays, Binary searchEasy