LeetCode:1.两数之和

LeetCode:1.两数之和

新建一个字典作为婚姻介绍所。nums里的值，逐个来介绍所找对象，没有合适的就先登记着，有合适的就牵手成功。

/**
 * @param {number[]} nums
 * @param {number} target
 * @return {number[]}
 */
var twoSum = function(nums, target) {
    let map=new Map()
    let diff
    let result=[]
    nums.forEach((item,index)=>{
        diff=target-item
        if(map.has(diff)){
            result=[index,map.get(diff)]
        }else{
            map.set(item,index)
        }
    })
    return result
};
//time 6ms 54mb  O(n)
// es6 api time fast

//for time 72ms 35mb

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