solution.py

# Your task is to write a function that does just what the title suggests
# (so, fair warning, be aware that you are not getting out of it just throwing a lame bas sorting method there)
# with an array/list/vector of integers and the expected number n of smallest elements to return.

# Also:

# the number of elements to be returned cannot be higher than the array/list/vector length;
# elements can be duplicated;
# in case of duplicates, just return them according to the original order (see third example for more clarity).

# Same examples and more in the test cases:
# first_n_smallest([1,2,3,4,5],3) == [1,2,3]
# first_n_smallest([5,4,3,2,1],3) == [3,2,1]
# first_n_smallest([1,2,3,4,1],3) == [1,2,1]
# first_n_smallest([1,2,3,-4,0],3) == [1,-4,0]
# first_n_smallest([1,2,3,4,5],0) == []


def first_n_smallest(arr, n):
    arr = sorted(enumerate(arr), key=lambda x: x[1])[:n]
    return [i[1] for i in sorted(arr, key=lambda x: x[0])]