Practice · judged on hidden tests
Problems
100 problems, ordered so each topic builds on the last.
- Not startedFind the middle in one passLinked lists, Two pointersEasy
- Not startedFitting the most value into the bagDynamic programming, ArraysMedium
- Not startedGroup anagramsStrings, Hash maps, SortingMedium
- Not startedHow deep does the tree goTreesEasy
- Not startedHow far the list is from sortedArrays, SortingHard
- Not startedHow long this price has been the bestArrays, Stacks and queuesMedium
- Not startedHow long until every orange has gone badMatrices, Stacks and queues, GraphsMedium
- Not startedHow long until it gets warmerArrays, Stacks and queuesMedium
- Not startedHow many digitsBasics, NumbersEasy
- Not startedHow many must you dropArrays, Sorting, GreedyMedium
- Not startedHow many nodes the loop goes roundLinked lists, Two pointersMedium
- Not startedHow many separate groups of friendsMatrices, GraphsMedium
- Not startedHow many triples add to zeroArrays, Two pointers, SortingMedium
- Not startedHow many ways down through the gridDynamic programming, Arrays, MatricesMedium
- Not startedHow many ways the queens fitBacktrackingHard
- Not startedHow many ways up the stairsDynamic programmingEasy
- Not startedHow many words start with thisStrings, TriesMedium
- Not startedIs it a palindromeStrings, Two pointersEasy
- Not startedIs the tree balancedTreesEasy
- Not startedIs this really a search treeTrees, Binary searchMedium
- Not startedLongest increasing subsequenceDynamic programming, Binary searchMedium
- Not startedLongest run of consecutive numbersArrays, Hash setsMedium
- Not startedLongest stretch with no repeatsStrings, Hash maps, Sliding windowMedium
- Not startedMaximum subarray sumDynamic programming, ArraysMedium
- Not startedMedian from a data streamHeaps, DesignHard