1var assert = require('assert');
2
3function twoSum(arr, goal) {
4  const results = [];
5  const hash = {};
6
7  for (let idx in arr) {
8    const difference = goal - arr[idx];
9    if (hash.hasOwnProperty(arr[idx])) {
10      results[0] = parseInt(hash[arr[idx]]);
11      results[1] = parseInt(idx);
12    } else {
13      hash[difference] = idx;
14    }
15  }
16
17  return results;
18}
19
20try {
21  assert.deepEqual(twoSum([1, 9, 13, 20, 47], 10), [0, 1]);
22
23  console.log(
24    'PASSED: ' + 'assert.deepEqual(twoSum([1, 9, 13, 20, 47], 10), [0, 1]);'
25  );
26} catch (err) {
27  console.log(err);
28}
29
30try {
31  assert.deepEqual(twoSum([3, 2, 4, 1, 9], 12), [0, 4]);
32
33  console.log(
34    'PASSED: ' + 'assert.deepEqual(twoSum([3, 2, 4, 1, 9], 12), [0, 4]);'
35  );
36} catch (err) {
37  console.log(err);
38}
39
40try {
41  assert.deepEqual(twoSum([], 10), []);
42
43  console.log('PASSED: ' + 'assert.deepEqual(twoSum([], 10), []);');
44} catch (err) {
45  console.log(err);
46}