/**
* @param {number[]} nums
* @param {number} target
* @return {number[]}
*/
var twoSum = function(nums, target) {
//利用map
let maps= new Map()
for(let i in nums){
num = target - nums[i]
if(maps.has(num)){
return [maps.get(num),i]
}
maps.set(nums[i],i)
}
};