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Python Basic - 1: Exercise-4 with Solution

Write a Python program to find unique triplets whose three elements gives the sum of zero from an array of n integers.

Pictorial Presentation: Sample Solution:

Python Code :

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))

Sample Output:

[(-6, 2, 4)]

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Python Code Editor :

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