0081-search-in-rotated-sorted-array-ii.rb

# frozen_string_literal: true

# 81. Search in Rotated Sorted Array II
# Medium
# https://leetcode.com/problems/search-in-rotated-sorted-array-ii

=begin
There is an integer array nums sorted in non-decreasing order (not necessarily with distinct values).
Before being passed to your function, nums is rotated at an unknown pivot index k (0 <= k < nums.length) such that the resulting array is [nums[k], nums[k+1], ..., nums[n-1], nums[0], nums[1], ..., nums[k-1]] (0-indexed). For example, [0,1,2,4,4,4,5,6,6,7] might be rotated at pivot index 5 and become [4,5,6,6,7,0,1,2,4,4].
Given the array nums after the rotation and an integer target, return true if target is in nums, or false if it is not in nums.
You must decrease the overall operation steps as much as possible.

Example 1:
Input: nums = [2,5,6,0,0,1,2], target = 0
Output: true

Example 2:
Input: nums = [2,5,6,0,0,1,2], target = 3
Output: false

Constraints:
* 1 <= nums.length <= 5000
* -104 <= nums[i] <= 104
* nums is guaranteed to be rotated at some pivot.
* -104 <= target <= 104
=end

# @param {Integer[]} nums
# @param {Integer} target
# @return {Boolean}
def search(nums, target)
  left = 0
  right = nums.length - 1

  while left <= right do
    mid = (left + right) / 2
    return true if nums[mid] == target

    if nums[left] < nums[mid]
      if nums[left] <= target && target < nums[mid]
        right = mid - 1
      else
        left = mid + 1
      end
    elsif nums[left] > nums[mid]
      if nums[mid] < target && target <= nums[right]
        left = mid + 1
      else
        right = mid - 1
      end
    else
      left += 1
    end
  end
  false
end

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

require "test/unit"
class Test_search < Test::Unit::TestCase
  def test_
    assert_equal true, search([2, 5, 6, 0, 0, 1, 2], 0)
    assert_equal false, search([2, 5, 6, 0, 0, 1, 2], 3)
  end
end