Given a list of numbers and a number k, return whether any two numbers from the list add up to k. For example, given [10, 15, 3, 7] and k of 17, return true since 10 + 7 is 17.

O(n^2)twoArrayElementsSum.js

/**
Given a list of numbers and a number k, return whether any two numbers from the list add up to k.

For example, given [10, 15, 3, 7] and k of 17, return true since 10 + 7 is 17.
*/

const arrayElementsSum = (arr, k) => {
  // If k - index exists in array, return true
  for (let i = 0; i < arr.length; i++) {
    const diff = k - arr[i];
    
    if (arr.includes(diff)) return true
  }
  
  return false;
}