1 Two Sum.js

/**
 * 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.
 * 给定一个整数数组 nums 和一个目标值 target，请你在该数组中找出和为目标值的 两个 整数。
 * 你可以假设每种输入只会对应一个答案。但是，你不能重复利用这个数组中同样的元素。
 */

/**
 * 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 = (nums, target) => {
  let res = []
  nums.forEach((num, index) => {
    for (let i = index + 1; i < nums.length; i++) {
      if (num + nums[i] === target) {
        res.push(index, i)
      }
    }
  })

  return [...new Set(res)]
}

console.log(twoSum([2, 7, 11, 15], 9))