0643-maximum-average-subarray-i.rb

# frozen_string_literal: true

# 643. Maximum Average Subarray I
# https://leetcode.com/problems/maximum-average-subarray-i
# Easy

=begin
You are given an integer array nums consisting of n elements, and an integer k.

Find a contiguous subarray whose length is equal to k that has the maximum average value and return this value. Any answer with a calculation error less than 10-5 will be accepted.

Example 1:
Input: nums = [1,12,-5,-6,50,3], k = 4
Output: 12.75000
Explanation: Maximum average is (12 - 5 - 6 + 50) / 4 = 51 / 4 = 12.75

Example 2:
Input: nums = [5], k = 1
Output: 5.00000

Constraints:
n == nums.length
1 <= k <= n <= 105
-104 <= nums[i] <= 104
=end

# @param {Integer[]} nums
# @param {Integer} k
# @return {Float}
deffind_max_average(nums,k)
max_sum=0
i=0
whilei < kdo
max_sum += nums[i]
i += 1
end

new_sum=max_sum

whilei < nums.lengthdo
new_sum += nums[i] - nums[i - k]
max_sum=new_sumifnew_sum > max_sum
i += 1
end
max_sum / k.to_f
end

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

require"test/unit"
classTest_max_vowels < Test::Unit::TestCase
deftest_
assert_equal12.75,find_max_average([1,12, -5, -6,50,3],4)
assert_equal5.0,find_max_average([5],1)
end
end