题解 | 【模板】序列操作

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

void async function () {
    // Write your code here
    const nums = [];
    while(line = await readline()){
        let [operate, a, b] = line.split(' ');
        a = Number(a);
        b = Number(b);
        switch(operate){
            case '1':{
                nums.push(a);
                break;
            }
            case '2':{
                nums.pop();
                break;
            }
            case '3':{
                console.log(nums[a]?nums[a]:undefined);
                break;
            }
            case '4':{
                nums.splice(a+1,0,b);
                break;
            }
            case '5':{
                nums.sort((a,b)=>a-b);
                break;
            }
            case '6':{
                nums.sort((a,b)=>b-a);
                break;
            }
            case '7':{
                console.log(nums.length);
                break;
            }
            case '8':{
                console.log(nums.join(' '));
                break;
            }
        }
    }
    rl.close();
}()