Lexicographic Numbers up to N

Problem

Return the integers from 1 through n in lexicographic order as strings compared character by character.

Start at 1 and repeatedly either descend by appending a zero when that stays within n, or move to the next sibling by incrementing and falling back to a parent. Stop after n numbers.

Hint

Falling back to the parent happens whenever the next sibling would exceed n.

Test cases

case 1

in: [13]

expected: [1,10,11,12,13,2,3,4,5,6,7,8,9]

case 2

in: [2]

expected: [1,2]

case 3

in: [1]

expected: [1]

case 4

in: [10]

expected: [1,10,2,3,4,5,6,7,8,9]

case 5

in: [20]

expected: [1,10,11,12,13,14,15,16,17,18,19,2,20,3,4,5,6,7,8,9]

Starter codePython

def lexicographic_numbers(n):
    # Your code here
    pass

5 test cases · run your code against them in the editor