[[-1, 2, 3], [4, 2, 1], [-2, 6, 4]] For example I have this two dimensional array, and I need to pick the combination of numbers (one from each sublist) that in total give some number, let's say -1, so the right numbers will be -1 from the first, 2 from the second and -2 from the third. What is the fastest and easiest way to do it?

CodePudding user response：

The easiest way would be to use itertools.product but that's not the fastest (it is simple brute force over all possible combinations):

from itertools import product

numbers = [[-1, 2, 3], [4, 2, 1], [-2, 6, 4]]

print(*(p for p in product(*numbers) if sum(p) == -1))
# (-1, 2, -2) 

print(*(p for p in product(*numbers) if sum(p) == 7))
# (-1, 4, 4) (-1, 2, 6) (2, 1, 4)

Getting something faster will require diving into recursion and dynamic programming which will no longer be the simplest way (there's always a trade off)