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H

3Sum

#9
arrayhashmap

Sort and use two pointers to find triplets summing to zero, skipping duplicates.

Example:

Input:[-1,0,1,2,-1,-4]
Output:[[-1,-1,2],[-1,0,1]]

Common Mistakes:

  • Off-by-one indexing
  • Not handling edge cases (null/empty)

Notes:

Edge cases: duplicates, empty inputs, negative numbers where applicable.

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3Sum