Find_Unique_Triplets.py

# Write a Python Program to find unique triplets whose three elements gives the sum of zero from an array of n integers.
def three_sum(nums):
    result = []
    nums.sort()
    for i in range(len(nums)-2):
        if i>0 and nums[i] == nums[i-1]:
            continue
        l, r = i+1, len(nums)-1
        while l < r:
            s = nums[i] + nums[l] + nums[r]
            if s > 0:
                r -= 1
            elif s < 0:
                l += 1
            else:
                # found three sum
                result.append((nums[i], nums[l], nums[r]))
                # remove duplicates
                while l < r and nums[l] == nums[l+1]:
                    l += 1
                    while l < r and nums[r] == nums[r-1]:
                        r -= 1
                        l += 1
                        r -= 1
                    return result

x = [1, -6, 4, 2, -1, 2, 0, -2, 0]
print(three_sum(x))