Practice Problem
3Sum
Difficulty: Medium
Find all unique triplets in an array that sum to zero, avoiding duplicate triplets in the result.
3Sum
Given an integer array nums, return all the triplets [nums[i], nums[j], nums[k]] such that i != j, i != k, and j != k, and nums[i] + nums[j] + nums[k] == 0.
Notice that the solution set must not contain duplicate triplets.
Examples
Example 1:
Input: nums = [-1, 0, 1, 2, -1, -4]
Output: [[-1, -1, 2], [-1, 0, 1]]
Explanation:
nums[0] + nums[1] + nums[2] = (-1) + 0 + 1 = 0
nums[1] + nums[2] + nums[4] = 0 + 1 + (-1) = 0
nums[0] + nums[3] + nums[4] = (-1) + 2 + (-1) = 0
The distinct triplets are [-1,-1,2] and [-1,0,1].Example 2:
Input: nums = [0, 1, 1]
Output: []
Explanation: The only possible triplet does not sum up to 0.Example 3:
Input: nums = [0, 0, 0]
Output: [[0, 0, 0]]
Explanation: The only possible triplet sums up to 0.Constraints
3 <= nums.length <= 3000-10^5 <= nums[i] <= 10^5
Expected Complexity
- Time: O(n^2)
- Space: O(1) extra space (excluding the output)
MEDIUM
Two Pointers
Arrays
Sorting
Intermediate
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Solution
Hints
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