题解 | #数据分类处理#

什么叫函数式啊？（后仰）

const rl = require("readline").createInterface({ input: process.stdin });
var iter = rl[Symbol.asyncIterator]();
const readline = async () => (await iter.next()).value;

void (async function () {
    const I = String(await readline())
        .split(" ")
        .slice(1);
    const R = String(await readline())
        .split(" ")
        .slice(1)
        .map(Number)
        .sort((a, b) => a - b)
        .filter((v, i, arr) => i == 0 || (i > 0 && arr[i - 1] != v));
    // console.debug(R)

    const results = R.filter((r) => I.some((el) => el.includes(r))).flatMap(
        (r) =>
            // 3 {6 { i, v }+}+
            [
                r,
                ...I.flatMap((el, index) =>
                    el.includes(r) ? [[index, el]] : []
                ).flatMap(
                    ([index, el], i, arr) =>
                        i == 0 ? [arr.length, index, el] : [index, el] // len, (i, el)+
                ),
            ]
    );

    console.log(results.length, ...results);
})();