[1] 两数之和

 1 /**
 2  * @param {number[]} nums
 3  * @param {number} target
 4  * @return {number[]}
 5  */
 6 var twoSum = function (nums, target) {
 7   const ll = nums.length
 8   const numsMap = new Map()
 9   for (let i = 0; ll - 1; i++) {
10     const complement = target - nums[i]
11     if (numsMap.get(complement) || numsMap.get(complement) === 0) {
12       return [i, numsMap.get(complement)]
13     }
14     numsMap.set(nums[i], i)
15 
16   }
17 };