在给定维度上聚合数组数据

Question

原谅n00b-ish问题,但我是数据结构的新手.我最近被要求将一个给定的数组聚合在另一个数组上,并产生一个基于树的结果.

有人可以给我一些关于如何获得这个输出的指示吗？

INPUT

var T = [
  ['COUNTRY', 'GENDER', 'MARITAL STATUS', 'SALES'],
  ['India', 'Female', 'Single', 2400],
  ['India', 'Male', 'Single', 5200],
  ['India', 'Female', 'Married', 4300],
  ['India', 'Male', 'Married', 3200],
  ['England', 'Female', 'Single', 1600],
  ['England', 'Female', 'Married', 2000],
  ['England', 'Male', 'Single', 4800],
  ['England', 'Male', 'Married', 6400],
];

var A = ['GENDER', 'MARITAL STATUS', 'COUNTRY'];

输出:为每个叶节点使用2*空格.

TOTAL 29900
  Female <Female Total>
    Single <Single Female Total>
      India <Single Female Total India>
      England <Single Female Total England>
    Married <Married Female Total>
      India <Married Female Total India>
      England <Married Female Total England>
  Male <Male Total>
    Single <Single Male Total>
      India <Single Male Total India>
      England <Single Male Total England>
    Married <Married Male Total>
      India <Married Male Total India>
      England <Married Male Total England>

Answer 1

结果可以用嵌套对象表示,每个内部对象都是一个子树,其总数为:

{
  total: 29900,
  Female: {
    total: 10300,
    Single: {
      total: 4000,
      India: {
        total: 2400
      },
      ...
    },
    ...
  },
  ...
}

只需循环遍历所有条目,并将值添加到相应的子树节点.

对于输出,您可以使用JSON.stringify和删除不必要的文本.

警告:下面的剧透

const T = [
  ['COUNTRY', 'GENDER', 'MARITAL STATUS', 'SALES'],
  ['India', 'Female', 'Single', 2400],
  ['India', 'Male', 'Single', 5200],
  ['India', 'Female', 'Married', 4300],
  ['India', 'Male', 'Single', 3200],
  ['England', 'Female', 'Single', 1600],
  ['England', 'Female', 'Married', 2000],
  ['England', 'Male', 'Single', 4800],
  ['England', 'Male', 'Married', 6400],
]
const A = ['GENDER', 'MARITAL STATUS', 'COUNTRY']

function aggregate(T, A) {
  const [fields, ...data] = T
  const columns = A.map(name => fields.findIndex(it => name === it))
  const count = fields.length - 1
  const result = { total: 0 }
  data.forEach(values => {
    result.total += values[count]
    //Go through the tree path, reduce is used here
    //to avoid creating extra tracking variable for current position
    columns.reduce((ref, index) => {
      const key = values[index]
      const next = ref[key] || (ref[key] = { total: 0 })
      next.total += values[count]
      return next
    }, result)
  })
  return result
}
function pack(data) {
  return Object.keys(data).reduce((result, key) => {
    if (key !== 'total') {
      const name = key + " " + data[key].total
      result[name] = pack(data[key])
    }
    return result
  }, {})
}
function format(result) {
  return JSON.stringify(pack(result), null, 2)
  .replace(/[^A-z0-9\n\s]/g, '')
  .replace(/\n?\s*\n/g, '\n')
}
function output(it) {
  const result = "TOTAL " + it.total + format(it)
  console.log(result)
}
output(aggregate(T, A))