题解 | #两数之和#

  * @param numbers int整型一维数组 
  * @param target int整型 
  * @return int整型一维数组
  */
function twoSum( numbers ,  target ) {
    let map = new Map(), res = new Array(2)
    for(let i = 0 ; i < numbers.length ; i++){
        let diff = target - numbers[i]
        if(map.has(diff)){
//             注意判断顺序问题，diff已在map中存在，即diff在前
//             同时，还要注意数组下标从1开始
            res[0] = map.get(diff) + 1
            res[1] = i + 1
            break
        }else {
            map.set(numbers[i] , i)
        }
    }
    return res
}
module.exports = {
    twoSum : twoSum
};