leetcode 15. 3Sum

https://leetcode.com/problems/3sum/description/

3Sum - LeetCode

 

class Solution:
    def threeSum(self, nums: List[int]) -> List[List[int]]:
        answer = []
        nums.sort()
 
        for i in range(len(nums)-2):
            if i>0 and nums[i] == nums[i-1]:
                continue
            
            left, right = i + 1, len(nums) - 1
 
            while left < right:
                sum = nums[i]+ nums[left]+nums[right]
 
                if sum<0:
                    left+=1
                elif sum>0:
                    right-=1
                else:
                    answer.append([nums[i], nums[left], nums[right]])
 
                    while left< right and nums[left] == nums[left+1]:
                        left+=1
                    while left< right and nums[right] == nums[right-1]:
                        right -=1
                    
                    left +=1
                    right -=1
        
        return answer