题解 | #【模板】栈#,使用策略模式，简化代码

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
    let len = await readline();
    let arr = [];
    let obj = {
        'push':(n)=>arr.push(n),
        'pop':()=>arr.pop()||'error',
        'top':()=>arr[arr.length-1]||'error'
    }
    for(let i = 0;i<len;i++){
        let str = await readline();
       str.split(' ')[0] !=='push'?console.log(obj[str.split(' ')[0]]()): obj[str.split(' ')[0]](str.split(' ')[1])
    }
}()