题解 | #数据分类处理#

const rl = require("readline").createInterface({ input: process.stdin });
let arr = []
rl.on('line', function(line) {
    arr.push(line)
})
rl.on('close', function() {
    // console.log(arr)
    let arr1 = arr[0].split(' ')
    let arr2 = arr[1].split(' ')
    arr1.shift()
    arr2.shift()
    let tempArr = Array.from(new Set(arr2))
    let temp = tempArr.sort((a, b) => {
        return a-b
    })
    // console.log(arr1, temp)
    let empty = []
    for (let i of temp) {
        let newArr = []
        let newArr2 = []
        arr1.forEach((item, index) => {
            if(item.includes(i)) {
                newArr2.push(i)
                newArr.push(index)
                newArr.push(item)
            }
        })
        // console.log(newArr, newArr2)
        if(newArr.length>0||newArr2.length>0) {
            newArr.unshift(newArr2.length)
            newArr.unshift(newArr2[0])
            // console.log(newArr)
            empty.push(...newArr)
            // console.log(empty)
        }   
    }
    empty.unshift(empty.length)
    console.log(empty.join(' '))

})

关键在于如何将序列一中匹配到元素及个数添加到序列元素前面