Hashing & maps
Trading memory for speed with hash sets and maps for O(1) lookups and counting.
Solved
0/8
1Two Sumhash map · complement lookupEasy2Contains Duplicatehash setEasy3Valid Anagramfrequency countEasy4Group Anagramshash map · canonical keyMedium5Longest Consecutive Sequencehash setMedium6Insert Delete GetRandom O(1)design · hash mapMedium74Sum IImeet in the middle · hash mapMedium8Insert Delete GetRandom O(1) - Duplicates alloweddesign · hash mapHard