Faaez Razeen

3Sum Closest

  • 1 min read
  • Array
  • Sorting
  • LC-Medium
  • Two Pointers

3 years ago

Approach: Sort + 2Sum

Same as 3Sum but instead of incrementing/decrementing the left/right pointers when the sum == target, we just return the sum.

Implementation
def threeSumClosest(nums: List[int], target: int) -> int: nums.sort() ans = math.inf for i in range(len(nums)): if i > 1 and nums[i] == nums[i - 1]: continue l, r = i + 1, len(nums) - 1 while l < r: sum_ = nums[i] + nums[l] + nums[r] if sum_ == target: return sum_ if abs(sum_ - target) < abs(ans - target): ans = sum_ elif sum_ < target: l += 1 while l < r and nums[l] == nums[l - 1]: l += 1 else: r -= 1 while r > l and nums[r] == nums[r + 1]: r -= 1 return ans