K-Sum Pattern (3Sum, 4Sum) Problems
5 K-Sum Pattern (3Sum, 4Sum) problems on LeetCode, a Two Pointers interview pattern, ranked by importance (how often it comes up in real interviews). Difficulty (ELO) and importance shown per problem.
| # | PROBLEM | DIFF | ELO | IMP | PATTERNS |
|---|---|---|---|---|---|
| 1 | 3Sum | Medium | 1534 | 91 | Sorting + Comparison · Complement Search (Two Sum Pattern) |
| 2 | 4Sum | Medium | 1581 | 72 | Sorting + Comparison |
| 3 | 3Sum SmallerPREMIUM | Easy | 1378 | 62 | Sorting + Comparison · Standard Binary Search |
| 4 | 3Sum Closest | Medium | 1427 | 58 | Sorting + Comparison |
| 5 | 3Sum With Multiplicity | Medium | 1711 | 53 | Frequency Counting / Hash Map Lookup · Combinatorics |
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