3sum.py

class Solution(object):
   def threeSum(self, nums):
      nums.sort()
      result = []
      for i in range(len(nums)-2):
         if i> 0 and nums[i] == nums[i-1]:
            continue
         l = i+1
         r = len(nums)-1
         while(l<r):
            sum = nums[i] + nums[l] + nums[r]
            if sum<0:
               l+=1
            elif sum >0:
               r-=1
            else:
               result.append([nums[i],nums[l],nums[r]])
               while l<len(nums)-1 and nums[l] == nums[l + 1] : l += 1
               while r>0 and nums[r] == nums[r - 1]: r -= 1
               l+=1
               r-=1
      return result
ob1 = Solution()
print(ob1.threeSum([-1,0,1,2,-1,-4]))