0016-3sum-closest.rb

# frozen_string_literal: true

# 16. 3Sum Closest
# https://leetcode.com/problems/3sum-closest/
# Medium

=begin
Given an integer array nums of length n and an integer target, find three integers in nums such that the sum is closest to target.

Return the sum of the three integers.

You may assume that each input would have exactly one solution.

Example 1:
Input: nums = [-1,2,1,-4], target = 1
Output: 2
Explanation: The sum that is closest to the target is 2. (-1 + 2 + 1 = 2).

Example 2:
Input: nums = [0,0,0], target = 1
Output: 0
Explanation: The sum that is closest to the target is 0. (0 + 0 + 0 = 0).

Constraints:
* 3 <= nums.length <= 500
* -1000 <= nums[i] <= 1000
* -104 <= target <= 104
=end

# @param {Integer[]} nums
# @param {Integer} target
# @return {Integer}
defthree_sum_closest(nums,target)
nums.sort!
result=Float::INFINITY

(0..nums.size - 3).eachdo |i|
left=i + 1
right=nums.size - 1

nextifi.positive? && nums[i] == nums[i - 1]

whileleft < right
sum=nums[i] + nums[left] + nums[right]
returnsumifsum == target

sum < target ? left += 1 : right -= 1
result=sumif(target - sum).abs < (target - result).abs
end
end

result
end

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

require"test/unit"
classTest_three_sum_closest < Test::Unit::TestCase
deftest_
assert_equal(2,three_sum_closest([-1,2,1, -4],1))
assert_equal(0,three_sum_closest([0,0,0],1))
end
end