Core
Arrays & Strings
The workhorse patterns for array and string problems. Master these and a large share of interview questions become pattern-matching instead of puzzles.
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Upgrade- Two SumEasy
- Group AnagramsMedium
- Top K Frequent ElementsMedium
- Product of Array Except SelfMedium
- Longest Consecutive SequenceMedium
- Two Sum II - Input Array Is SortedMedium
- 3SumMedium
- Container With Most WaterMedium
- Longest Substring Without Repeating CharactersMedium
- Longest Repeating Character ReplacementMedium
- Minimum Window SubstringHard
- Subarray Sum Equals KMedium
- Maximum SubarrayMedium
- Trapping Rain WaterHard