1.two-sum.js

/*
 * @lc app=leetcode id=1 lang=javascript
 *
 * [1] Two Sum
 *
 * https://leetcode.com/problems/two-sum/description/
 *
 * algorithms
 * Easy (40.29%)
 * Total Accepted:    1.4M
 * Total Submissions: 3.5M
 * Testcase Example:  '[2,7,11,15]\n9'
 *
 * Given an array of integers, return indices of the two numbers such that they
 * add up to a specific target.
 *
 * You may assume that each input would have exactly one solution, and you may
 * not use the same element twice.
 *
 * Example:
 *
 *
 * Given nums = [2, 7, 11, 15], target = 9,
 *
 * Because nums[0] + nums[1] = 2 + 7 = 9,
 * return [0, 1].
 *
 *
 *
 *
 */
/**
 * @param {number[]} nums
 * @param {number} target
 * @return {number[]}
 */
const twoSum = function(nums, target) {
  let firstIndex;
  let secondIndex;
  nums.forEach((num, index) => {
    nums.slice(0, index).forEach((nestNum, nestIndex) => {
      if (num + nestNum === target) {
        firstIndex = index;
        secondIndex = nestIndex;
      }
    });
  });

  return [firstIndex, secondIndex];
};