Triplet Sum

Given an integer array nums and an integer target, return all unique triplets [a,b,c] such that a + b + c = target. The solution set must not contain duplicate triplets.

Input:  nums = [-1,0,1,2,-1,-4], target = 0
Output: [[-1,-1,2],[-1,0,1]]

export function tripletSum(nums: number[], target: number): number[][] {
  nums.sort((a, b) => a - b);
  const res: number[][] = [];

  for (let i = 0; i < nums.length - 2; i++) {
    if (i > 0 && nums[i] === nums[i - 1]) continue;

    let l = i + 1, r = nums.length - 1;
    
    while (l < r) {
      const sum = nums[i] + nums[l] + nums[r];
      if (sum === target) {
        res.push([nums[i], nums[l], nums[r]]);
        l++; r--;
        while (l < r && nums[l] === nums[l - 1]) l++;
        while (l < r && nums[r] === nums[r + 1]) r--;
      } else if (sum < target) {
        l++;
      } else {
        r--;
      }
    }
  }
  return res;
}