[JS & Stack] 10828번: 스택

 

const fs = require('fs');
// const input = fs.readFileSync('./testcase.txt').toString().trim();
const input = fs.readFileSync('/dev/stdin').toString().trim();

const inputs = input.split('\n');
const N = inputs[0];

function initMethodInArrayPrototype() {
    if (
        Array.prototype.at === undefined ||
        typeof Array.prototype.at !== 'function'
    ) {
        Array.prototype.at = (index) => {
            if (index >= 0) {
                if (index < this.length) return this[index];
                else return undefined;
            }
            else {
                const ridx = index * -1;
                if (ridx > this.length) return undefined;
                return this[this.length - ridx];
            }
        }
    }
}

class Stack {
    constructor() {
        this.stack = [];
    }
    push(x) {
        this.stack.push(x);
    }
    pop() {
        if (this.stack.length === 0) {
            return -1;
        } else {
            return this.stack.pop();
        }
    }
    size() {
        return this.stack.length;
    }
    empty() {
        return this.stack.length ? 0 : 1;
    }
    top() {
        if (this.stack.length) {
            return this.stack.at(-1);
        } else {
            return -1;
        }
    }
}

initMethodInArrayPrototype();
const stack = new Stack();
let answer = '';

for (let i = 1; i <= N; i++) {
    const [req, num] = [...inputs[i].split(' ')];
    if (req === 'push') {
        stack.push(+num);
    }
    if (req === 'pop') {
        answer += stack.pop() + '\n';
    }
    if (req === 'size') {
        answer += stack.size() + '\n';
    }
    if (req === 'top') {
        answer += stack.top() + '\n';
    }
    if (req === 'empty') {
        answer += stack.empty() + '\n';
    }
}

console.log(answer);

https://www.acmicpc.net/problem/10828

10828번: 스택