AlgoDaily - Contiguous Subarray Sum

To make the brute force more efficient, we will be using a very popular data structure named: Hash Table.

A hash table keeps a key-value pair in a table using a hash function. As the hash function directly returns the memory address of the value given a key, its search, insert, and delete operations are in constant O(1) time.

We will be using a hash table to store the cumulative sum of the array as a key and its ending elements index as the value.

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var assert = require('assert');
​
function subarraySum(nums, n) {
  // hash of prefix sums
​
  // Fill in this method
  return nums;
}
​
const arr = [1, 2, 3],
  sum = 5;
console.log(subarraySum(arr, sum));
​
try {
  assert.equal(subarraySum([1, 2, 3], 3), true);
​
  console.log('PASSED: ' + 'assert.equal(subarraySum([ 1, 2, 3 ], 3), true)');
} catch (err) {
  console.log(err);
}
​
try {
  assert.equal(subarraySum([], 3), false);
​
  console.log('PASSED: ' + 'assert.equal(subarraySum([], 3), false)');
} catch (err) {
  console.log(err);

OUTPUT

Results will appear here.