🎲 백준 2573번 빙산

백준 2573번

💡 기존 블럭 수 세기 코드에 얼음 녹이는 코드를 추가해 풀었다.

코드

const fs = require('fs'); 
let input = fs.readFileSync('/dev/stdin').toString().trim().split('\n');
const [N, M] = input.shift().split(" ").map(Number);
input = input.map((el) => el.split(" ").map(Number));

const dir = [
  [0, 1],
  [0, -1],
  [1, 0],
  [-1, 0],
];

let visited;
let minus = Array.from(new Array(N), () => new Array(M).fill(0));

const bfs = (y, x) => {
  const queue = [[y, x]];
  visited[y][x] = true;
  while (queue.length) {
    const [locY, locX] = queue.shift();
    for (let d = 0; d < 4; d++) {
      const nextLocY = locY + dir[d][0];
      const nextLocX = locX + dir[d][1];
      if (
        nextLocY <= 0 ||
        nextLocX <= 0 ||
        nextLocY >= N - 1 ||
        nextLocX >= M - 1
      )
        continue;
      if (visited[nextLocY][nextLocX]) continue;
      if (input[nextLocY][nextLocX]) {
        queue.push([nextLocY, nextLocX]);
        visited[nextLocY][nextLocX] = true;
      }
    }
  }
};

const meltingIce = () => {
  for (let i = 1; i < N - 1; i++) {
    for (let j = 1; j < M - 1; j++) {
      if (input[i][j]) {
        for (let d = 0; d < 4; d++) {
          const nextI = i + dir[d][0];
          const nextJ = j + dir[d][1];
          if (nextI < 0 || nextJ < 0 || nextI >= N || nextJ >= M) continue;
          if (!input[nextI][nextJ]) minus[i][j]--;
        }
      }
    }
  }
};

let year = 0;
while (true) {
  let block = 0;
  visited = Array.from(new Array(N), () => new Array(M).fill(false));

  for (let i = 1; i < N - 1; i++) {
    for (let j = 1; j < M - 1; j++) {
      if (!visited[i][j] && input[i][j]) {
        bfs(i, j);
        block++;
      }
    }
  }
  if (block >= 2) return console.log(year);
  if (!block) return console.log(0);

  minus = Array.from(new Array(N), () => new Array(M).fill(0));

  meltingIce();

  for (let i = 1; i < N - 1; i++) {
    for (let j = 1; j < M - 1; j++) {
      input[i][j] += minus[i][j];
      if (input[i][j] < 0) input[i][j] = 0;
    }
  }
  year++;
}