문제 풀이(백준에서는 입출력 관련 오류가 있음)

keylogger.js

// https://www.acmicpc.net/problem/5397

function stdin_text() {
    const readline = require('readline')
    const rl = readline.createInterface({
        input: process.stdin,
        output: process.stdout
    });
	const input = [];
	let isFirstLine = false;
	let testcases = 0;
	let i = 0;

    rl.on('line', function(line){
		if (!isFirstLine) {
			testcases = parseInt(line);
			isFirstLine = true;
		}
		else {
			console.log(keyLogger(line));
			i++;
			if (i === testcases) {
				rl.close();
			}
		}
    });
    rl.on('close', function(){
        process.exit();
    });
}

class Node {
	constructor(data) {
		this.data = data;
		this.next = null;
		this.previos = null;
	}
}

class LinkedList {
	constructor() {
		this.head = null;
		this.tail = null;
	}

	add(node) {
		if (this.head === null) {
			this.head = node;
			this.tail = node;
		}
		else {
			node.previos = this.tail;
			this.tail.next = node;
			this.tail = node;
		}
		return this.tail;
	}

	getHead() {
		return this.head;
	}

	addNext(target, node) {
		if (target !== null) {
			const nextNode = target.next;

			target.next = node;
			node.previos = target;
			node.next = nextNode;
			if (nextNode !== null)
				nextNode.previos = node;
			return node;
		}
		else {
			this.head = node;
			return this.head;
		}
	}

	remove(target) {
		if (target != null) {
			if (target.previos === null) {
				if (target.next === null) {
					this.head = null;
					return null;
				}
				else {
					this.head = target.next;
					return this.head
				}
			}
			else {
				const previosNode = target.previos;
				const nextNode = target.next;

				if (previosNode == null) {
					this.head = nextNode;
					return this.head;
				}
				else {
					previosNode.next = nextNode;
					if (nextNode != null)
						nextNode.previos = previosNode;
					return this.previosNode
				}
			}
		}
		return target;
	}

	toString() {
		let tempNode = this.head;
		const strArray = [];

		while (tempNode) {
			strArray.push(tempNode.data);
			tempNode = tempNode.next;
		}
		return strArray.join('');
	}

	print() {
		let tempNode = this.head;

		console.log("--------------");
		while (tempNode) {
			console.log(tempNode.data);
			tempNode = tempNode.next;
		}
	}
}

function keyLogger(line) {
	const passowrdList = new LinkedList();
	const passowrd = [];
	let cursor = passowrdList.getHead();

	for (let ch of line) {
		if (ch === '<') {
			if (cursor != null && cursor.previos != null) {
				cursor = cursor.previos;
			}
		}
		else if (ch === '>') {
			if (cursor != null && cursor.next != null) {
				cursor = cursor.next;
			}
		}
		else if (ch === '-') {
			cursor = passowrdList.remove(cursor);
		}
		else {
			cursor = passowrdList.addNext(cursor, new Node(ch));
		}
	}
	return passowrdList.toString();
}

stdin_text();