[백준] 16935번: 배열 돌리기 3 (JavaScript, NodeJS)

 

정답 풀이

const path = process.platform === "linux" ? "/dev/stdin" : "input.txt"; // 리눅스로 테스트할 땐 따로 설정해주어야 합니다.

let input = require("fs")
  .readFileSync(path)
  .toString()
  .trim()
  .split("\n")
  .map(i => i.split(' ').map(Number));

/* input 정리 */
const [N, M, R] = input.shift();
const calculators = input.pop();

/* 문제 풀이 */
const go = (...args) => args.reduce((a, f) => f(a));

for (const calculator of calculators) {
  switch (calculator) {
    case 1: upDownReverse(); break;
    case 2: leftRightReverse(); break;
    case 3: right90degreeRotate(); break;
    case 4: left90degreeRotate(); break;
    case 5: divideFourSectionAndRotateRight(); break;
    case 6: divideFourSectionAndRotateLeft(); break;
  }
}

input.forEach(i => console.log(i.join(' ')));

// 1
function upDownReverse() {
  input = [...input].reverse();
}

// 2
function leftRightReverse() {
  input = input.map(row => [...row].reverse());
}

// 3
function right90degreeRotate() {
  const n = input.length;
  const m = input[0].length;
  const newArray = Array.from({ length: m }, () => Array.from({ n }));

  for (let i = 0; i < m; i++) {
    for (let j = 0; j < n; j++) {
      newArray[i][j] = input[n - j - 1][i]; 
    }
  }

  input = newArray
}

// 4
function left90degreeRotate() {
  return go(
    input,
    right90degreeRotate,
    right90degreeRotate,
    right90degreeRotate,
  );
}

// 5
function divideFourSectionAndRotateRight() {
  const n = input.length / 2;
  const m = input[0].length / 2;
  const top = input.slice(0, n);
  const bottom = input.slice(n);

  const part1 = top.map(row => row.slice(0, m));
  const part2 = top.map(row => row.slice(m));
  const part3 = bottom.map(row => row.slice(0, m));
  const part4 = bottom.map(row => row.slice(m));

  input = [
    ...part3.map((row, index) => [...row, ...part1[index]]),
    ...part4.map((row, index) => [...row, ...part2[index]]),
  ];
}

// 6
function divideFourSectionAndRotateLeft() {
  return go(
    input,
    divideFourSectionAndRotateRight,
    divideFourSectionAndRotateRight,
    divideFourSectionAndRotateRight,
  );
}