BOJ-13549 (숨바꼭질3)

포인트

• 왜 아래는 되고

    if (next < 0 || next > 100000) continue
    if (visits[next]) continue

  아래는 안되는지 모르겠다.

    if (next >= 0 && next <= 100000 && visits[next] === 0) {

const fs = require("fs");
const [n, k] = fs
  .readFileSync("/dev/stdin")
  .toString()
  .trim()
  .split(" ")
  .map((v) => Number(v));

const move = [(v) => v * 2, (v) => v - 1, (v) => v + 1];

const queue = [];

const visits = Array(100000).fill(0);

function bfs(startVal) {
  queue.push({ v: startVal, t: 0 });
  visits[startVal] = 1;

  while (queue.length) {
    const { v, t } = queue.shift();

    if (v === k) {
      return t;
    }

    for (let i = 0; i < move.length; i++) {
      const next = move[i](v);
      if (next < 0 || next > 100000) continue;
      if (visits[next]) continue;

      visits[next] = 1;

      if (i === 0) queue.unshift({ v: next, t });
      else queue.push({ v: next, t: t + 1 });
    }
  }
}

console.log(bfs(n));