0066-plus-one.rb

# frozen_string_literal: true

# 66. Plus One
# https://leetcode.com/problems/plus-one

=begin

You are given a large integer represented as an integer array digits, where each digits[i] is the ith digit of the integer. The digits are ordered from most significant to least significant in left-to-right order. The large integer does not contain any leading 0's.
Increment the large integer by one and return the resulting array of digits.

# Constraints:

* 1 <= digits.length <= 100
* 0 <= digits[i] <= 9
* digits does not contain any leading 0's.
=end

# @param {Integer[]} digits
# @return {Integer[]}
defplus_one(digits)
carryover,pointer=1, -1

whilecarryover.positive?
breakdigits.unshift(carryover)ifdigits[pointer].nil?

sum=digits[pointer] + carryover
carryover=sum / 10
digits[pointer]=sum % 10
pointer -= 1
end

digits
end

# ********************#
# TEST #
# ********************#

require"test/unit"
classTest_plus_one < Test::Unit::TestCase
deftest_
assert_equal[1,2,4],plus_one([1,2,3])
assert_equal[4,3,2,2],plus_one([4,3,2,1])
assert_equal[1,0],plus_one([9])
end
end