sumTwoNumbers

class Solution:
    def sumTwo(self, arr, target):
        if len(arr) < 2:
            return
        res = set()
        arr.sort()
        for i in range(len(arr)):
            left = i
            right = len(arr) - 1
            while left < right:
                total = arr[left] + arr[right]
                if total < target:
                    left += 1
                elif total > target:
                    right -= 1
                else:
                    res.add((arr[left], arr[right]))
                    while left < right and arr[left] == arr[left + 1]:
                        left += 1
                    while left < right and arr[right] == arr[right -1]:
                        right -= 1
                    left += 1
                    right -= 1

        return res

arr = [-1,3,0,2,1,7,8,9,6]
target = 9
s = Solution()
print(arr)
print(s.sumTwo(arr,target))

# output: {(1, 8), (0, 9), (2, 7), (3, 6)}