Given a list of numbers an a number k, return whether any two number from the list add up to k

listNumbersPossibleSum.js

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

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

Bonus can you do in a single pass?
*/

array = [7,15,3,7,8,3,4,100]
k = 23

// e1 + e2 = k
// e2 = k - e1

verifySol = (_array, _k) => {
  hashMap = {};
  for(let e of _array) {
    if (hashMap[e]) {
      return true;
    } else {
      // Store the value that we are looking for
      // which is: e2 = k - e1
      hashMap[k-e] = true
    }
  }
  return false;
}

console.log(`Given the list ${array} and a desired sum ${k}: `)
console.log()

let res = verifySol(array, k);
console.log("Result using solution 1 (single pass hash map)", res);