[Java] 2차원 배열 돌리기

 

💡시계 방향으로 90도 회전

 

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

public class Main_rotate {
	
	static int N,M;
	static int[][] arr;

	public static void main(String[] args) throws IOException{
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		StringTokenizer st = new StringTokenizer(br.readLine());
		
		N = Integer.parseInt(st.nextToken());
		M = Integer.parseInt(st.nextToken());
		
		int num = 1;
		arr = new int[N][M];
		for(int i=0;i<N;i++) {
			for(int j=0;j<M;j++) {
				arr[i][j] = num++;
			}
		}
		
		int[][] arr2 = new int[M][N];
		for(int i=0;i<N;i++) {
			for(int j=0;j<M;j++) {
				arr2[j][N-1-i] = arr[i][j];
			}
		}
        
		for(int i=0;i<N;i++) {
			for(int j=0;j<M;j++) {
				System.out.print(arr[i][j]+"\t");
			}
			System.out.println();
		}
		System.out.println(" ========================== ");
		for(int i=0;i<M;i++) {
			for(int j=0;j<N;j++) {
				System.out.print(arr2[i][j]+"\t");
			}
			System.out.println();
		}
		
	}

}

 

 

💡반시계 방향으로 90도 회전

 

 

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

public class Main_rotate {
	
	static int N,M;
	static int[][] arr;

	public static void main(String[] args) throws IOException{
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		StringTokenizer st = new StringTokenizer(br.readLine());
		
		N = Integer.parseInt(st.nextToken());
		M = Integer.parseInt(st.nextToken());
		
		int num = 1;
		arr = new int[N][M];
		for(int i=0;i<N;i++) {
			for(int j=0;j<M;j++) {
				arr[i][j] = num++;
			}
		}
		
		arr2 = new int[M][N];
		for(int i=0;i<N;i++	) {
			for(int j=0;j<M;j++) {
				arr2[M-1-j][i] = arr[i][j];
			}
		}
		
		System.out.println(" ======= 반시계 방향 90도 회전 ======= ");
		for(int i=0;i<M;i++) {
			for(int j=0;j<N;j++) {
				System.out.print(arr2[i][j]+"\t");
			}
			System.out.println();
		}
	}

}