js 循环**数据结构处理**问题, 遇到瓶颈,求方案(考虑性能)

Question

数据结构描述var users = [    {id: 1, username: '123', authPlayerIds: [1001, 1002, 1003]},    {id: 2, username: 'qwe', authPlayerIds: [1003, 1004, 1005]},    {id: 3, username: 'fdf', authPlayerIds: [1002, 1007, 1088]},    {id: 4, username: 'dsa', authPlayerIds: [1001, 1022, 1033]},    ...    // 注意: 数据在`20000`以上]需求描述计算authPlayerIds字段中的每一项(id)所出现的次数以及包含它的用户(user)性能优先(首选)处理结束后的数据结构var authPlayers = {    '1001': [        {id: 1, username: '123'},        {id: 4, username: 'dsa'}    ],    '1002': [        {id: 1, username: '123'},        {id: 3, username: 'fdf'},        {id: 4, username: 'dsa'},    ],    '1003': [        {id: 1, username: '123'},        {id: 2, username: 'qwe'},    ]}语言及工具描述JavaScriptNode.jsLodashunderscoreasyncbluebird一切你想用的工具都可以在线急等...是时候表演真正的技术了

Answer 1

var users = [

    {id: 1, username: '123', authPlayerIds: [1001, 1002, 1003]},

    {id: 2, username: 'qwe', authPlayerIds: [1003, 1004, 1005]},

    {id: 3, username: 'fdf', authPlayerIds: [1002, 1007, 1088]},

    {id: 4, username: 'dsa', authPlayerIds: [1001, 1022, 1033]},

]

var ret = {}

users.forEach(function(e){

    var ap = e.authPlayerIds

    ap.forEach(function(p){

        var t = {}

        if (ret[p]) {

            t.id = e.id || null

            t.username = e.username || null

        } else {

            ret[p] = []

            t.id = e.id || null

            t.username = e.username || null

        }

        ret[p].push(t)

    })

})