text: 
  /**
   * Given an array and a target, return the indices of the 2 number that sum up target
   *
   * @param {number[]} nums
   * @param {numer} target
   * @returns
   *
   * @runtime O(n)
   */
  function twoSum(nums, target) {
    const map = new Map();
  
    for (let i = 0; i < nums.length; i++) {
      const diff = target - nums[i];
      if (map.has(diff)) {
        return [map.get(diff), i];
      }
      map.set(nums[i], i);
    }
  
    return [];
  }
  
  module.exports = twoSum;
  