🎲 백준 2606번 바이러스

백준 2606번

코드

const fs = require('fs'); 
const input = fs.readFileSync('/dev/stdin').toString().trim().split('\n');

const N = +input.shift();
const E = +input.shift();

let graph = {};

for (let i = 1; i <= N; i++) {
  graph[i] = [];
}

for (let i = 0; i < E; i++) {
  const [a, b] = input[i].split(" ");
  graph[a].push(b);
  graph[b].push(a);
}

let checked = [];
willCheck = ['1'];

while (willCheck.length !== 0) {
  const check = willCheck.shift();
  if (!checked.includes(check)) {
    checked.push(check);
    willCheck.push(...graph[check]);
  }
}

console.log(checked.length - 1);