The challenge
Write an algorithm that takes an array and moves all of the zeros to the end, preserving the order of the other elements.
move_zeros([1, 0, 1, 2, 0, 1, 3]) # returns [1, 1, 2, 1, 3, 0, 0]
The solution in Python code
Option 1:
def move_zeros(arr):
l = [i for i in arr if isinstance(i, bool) or i!=0]
return l+[0]*(len(arr)-len(l))
Option 2:
def move_zeros(array):
return sorted(array, key=lambda x: x==0 and type(x) is not bool)
Option 3:
def move_zeros(array):
return [a for a in array if isinstance(a, bool) or a != 0] + [a for a in array if not isinstance(a, bool) and a == 0]
Test cases to validate our solution
import test
from solution import move_zeros
@test.it("Basic tests")
test.assert_equals(move_zeros(
[1, 2, 0, 1, 0, 1, 0, 3, 0, 1]),
[1, 2, 1, 1, 3, 1, 0, 0, 0, 0])
test.assert_equals(move_zeros(
[9, 0, 0, 9, 1, 2, 0, 1, 0, 1, 0, 3, 0, 1, 9, 0, 0, 0, 0, 9]),
[9, 9, 1, 2, 1, 1, 3, 1, 9, 9, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0])
test.assert_equals(move_zeros([0, 0]), [0, 0])
test.assert_equals(move_zeros([0]), [0])
test.assert_equals(move_zeros([]), [])
