ruby version: leetcode two sum problem

two_sum.rb

# Ruby version leetcode problem two_sum
def two_sum(nums, target)
  hash = {}
  nums.each.with_index do |k, i|
    return [ hash[target - k], i ] if hash.key?(target - k)
    hash[k] = i
  end
end

data = [2,1,5,4,9,6]

target = 10 

result = two_sum(data, target)

puts result.inspect # [1, 4]

Javascript version:

function twoSum(nums, target) {

  const hash = {};

  for (let i = 0; i < nums.length; i++) {

    const currentNum = nums[i];
    const complement = target - currentNum;

    if (hash.hasOwnProperty(complement)) {
      return [hash[complement], i];
    }

    hash[currentNum] = i;
  }

  return [];

}

Javascript v2: Using reduce

function twoSum (nums, target) {
  const hash = {};
  return nums.reduce((acc, currentNum, i) => {
    const complement = target - currentNum;
    if (hash.hasOwnProperty(complement)) {
      return [hash[complement], i];
    }
    hash[currentNum] = i;
    return acc;
  }, []);
}