21.08.17 - [BOJ] 16926. 배열 돌리기 1

[suhyunsim]

문제

• 16926

핵심 아이디어

1. 배열을 먼저 그룹 짓는 것이 필요 -> 1차원 배열
2. 1차원 배열 R번 회전
3. 그룹에 넣기

어려운 점, 실수

풀이

package main.java.com.poogle.BOJ.Q16927;

import java.util.ArrayList;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int m = sc.nextInt();
        int r = sc.nextInt();
        int[][] a = new int[n][m];
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < m; j++) {
                a[i][j] = sc.nextInt();
            }
        }
        ArrayList<ArrayList<Integer>> groups = new ArrayList<>();
        int groupn = Math.min(n, m) / 2;
        for (int k = 0; k < groupn; k++) {
            ArrayList<Integer> group = new ArrayList<>();
            for (int j = k; j < m - k; j++) {
                group.add(a[k][j]);
            }
            for (int i = k + 1; i < n - k - 1; i++) {
                group.add(a[i][m - k - 1]);
            }
            for (int j = m - k - 1; j > k; j--) {
                group.add(a[n - k - 1][j]);
            }
            for (int i = n - k - 1; i > k; i--) {
                group.add(a[i][k]);
            }
            groups.add(group);
        }
        for (int k = 0; k < groupn; k++) {
            ArrayList<Integer> group = groups.get(k);
            int len = group.size();
            int index = r % len;
            for (int j = k; j < m - k; j++, index = (index + 1) % len) {
                a[k][j] = group.get(index);
            }
            for (int i = k + 1; i < n - k - 1; i++, index = (index + 1) % len) {
                a[i][m - k - 1] = group.get(index);
            }
            for (int j = m - k - 1; j > k; j--, index = (index + 1) % len) {
                a[n - k - 1][j] = group.get(index);
            }
            for (int i = n - k - 1; i > k; i--, index = (index + 1) % len) {
                a[i][k] = group.get(index);
            }
        }
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < m; j++) {
                System.out.print(a[i][j] + " ");
            }
            System.out.println();
        }
    }
}