All problems
Stacks and queues problems
14 problems: 3 easy, 8 medium and 3 hard. Start at the top; each one assumes the ones above it.
- Not startedEasyCancel out neighbouring pairsStacks and queues, Strings
- Not startedEasyThe next bigger number to the rightStacks and queues, Arrays
- Not startedEasyValid parenthesesStacks and queues, Strings
- Not startedMediumArithmetic without bracketsStacks and queues, Strings
- Not startedMediumHow long this price has been the bestStacks and queues, Arrays
- Not startedMediumHow long until every orange has gone badMatrices, Stacks and queues, Graphs
- Not startedMediumHow long until it gets warmerStacks and queues, Arrays
- Not startedMediumReading a tree one level at a timeStacks and queues, Trees
- Not startedMediumThe first letter that has appeared only once, so farStacks and queues, Hash maps, Strings
- Not startedMediumThe first negative number in every windowStacks and queues, Arrays, Sliding window
- Not startedMediumWhat the tree looks like from the rightStacks and queues, Trees
- Not startedHardThe biggest rectangle inside a histogramStacks and queues, Arrays
- Not startedHardThe largest number in every windowStacks and queues, Arrays, Sliding window
- Not startedHardWater held between the barsStacks and queues, Arrays, Two pointers