All problems
Hash maps problems
10 problems: 4 easy, 6 medium and 0 hard. Start at the top; each one assumes the ones above it.
- Not startedEasyThe number more than halfArrays, Hash maps
- Not startedEasyThe number that appears onceArrays, Hash maps, Bit manipulation
- Not startedEasyTwo sumArrays, Hash maps
- Not startedEasyValid anagramStrings, Hash maps, Sorting
- Not startedMediumA cache that forgets what you have not usedLinked lists, Hash maps, Design
- Not startedMediumGroup anagramsStrings, Hash maps, Sorting
- Not startedMediumLongest stretch with no repeatsStrings, Hash maps, Sliding window
- Not startedMediumMost frequent numbersArrays, Hash maps, Heaps, Sorting
- Not startedMediumThe first letter that has appeared only once, so farStrings, Stacks and queues, Hash maps
- Not startedMediumTwo baskets, one row of treesArrays, Hash maps, Sliding window