def threesum(arr, target):

res = []

arr.sort()

length = len(arr)

for i in range(length -2):

if i > 0 and arr[i] == arr[i-1]:

continue

l = i +1

r = length -1

while l < r:

total = arr[i] + arr[l] + arr[r]

if total < target:

l += 1

elif total > target:

r -=1

else:

res.append([arr[i],arr[l],arr[r]])

while l < r and arr[l] == arr[l+1]:

l += 1

while l < r and arr[r] == arr[r-1]:

r -= 1

l +=1

r -=1

return res

print(threesum([-1,0,1,2,-1,-4],0))