Node.js) 백준 11558번: The Game of Death

https://www.acmicpc.net/problem/11558

11558번: The Game of Death

const fs = require('fs');
const input = fs.readFileSync("./dev/stdin").toString().trim().split("\n").map(v => +v);

let answer = [];

let T = input.shift();

for (let i = 0; i < T; i++) {
  let N = input.shift();
  let arr = new Array(N + 1);
  let isVisited = new Array(N + 1).fill(false);
  for (let j = 1; j <= N; j++) {
    arr[j] = input.shift();
  }
  let J = arr[1];
  isVisited[1] = true;
  let cnt = 1;
  while (true) {
    if (J == N) {
      answer.push(cnt);
      break;
    } else {
      J = arr[J];
      if (isVisited[J]) {
        answer.push(0)
        break;
      }
      isVisited[J] = true;
      cnt++;
    }
    
  }
}

console.log(answer.join('\n'));