[BOJ] 백준 12100 2024 Easy

회전 방식으로 보완 !

 

 

[문제]

https://www.acmicpc.net/problem/12100

 

 

[소스 코드]

1. 4가지 방향을 기준으로 수행

import java.io.*;
import java.util.*;

public class Main {
	static int[] dr = {-1,1,0,0};
	static int[] dc = {0,0,-1,1};
	public static void main(String[] args) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		StringTokenizer st;
		int n = Integer.parseInt(br.readLine());
		int[][] map = new int[n][n];
		for(int i=0;i<n;i++) {
			st = new StringTokenizer(br.readLine());
			for(int j=0;j<n;j++) {
				map[i][j] = Integer.parseInt(st.nextToken());
			}
		}
		int result = 0;
		int total = (int)Math.pow(4, 5);
		for(int t=0;t<total;t++) {
			int mode = t;
			int[][] copyM = new int[n][n];
			for(int i=0;i<n;i++) {
				copyM[i] = map[i].clone();
			}
			for(int m=0;m<5;m++) {
				int rot = mode % 4;
				mode /= 4;
				if(rot==0) {
					for(int j=0;j<n;j++) {
						int idx = 0;
						int[] temp = new int[n];
						for(int i=0;i<n;i++) {
							if(copyM[i][j]!=0) {
								if(temp[idx]==0) temp[idx] = copyM[i][j];
								else {
									if(temp[idx]==copyM[i][j]) temp[idx++] *= 2;
									else temp[++idx] = copyM[i][j];
								}
							}
						}
						for(int i=0;i<n;i++) {
							copyM[i][j] = temp[i];
						}
					}
					
				}
				else if(rot==1) {
					for(int j=0;j<n;j++) {
						int idx = n-1;
						int[] temp = new int[n];
						for(int i=n-1;i>=0;i--) {
							if(copyM[i][j]!=0) {
								if(temp[idx]==0) temp[idx] = copyM[i][j];
								else {
									if(temp[idx]==copyM[i][j]) temp[idx--] *= 2;
									else temp[--idx] = copyM[i][j];
								}
							}
						}
						for(int i=0;i<n;i++) {
							copyM[i][j] = temp[i];
						}
					}
				}
				else if(rot==2) {
					for(int i=0;i<n;i++) {
						int idx = 0;
						int[] temp = new int[n];
						for(int j=0;j<n;j++) {
							if(copyM[i][j]!=0) {
								if(temp[idx]==0) temp[idx] = copyM[i][j];
								else {
									if(temp[idx]==copyM[i][j]) temp[idx++] *= 2;
									else temp[++idx] = copyM[i][j];
								}
							}
						}
						for(int j=0;j<n;j++) {
							copyM[i][j] = temp[j];
						}
					}
				}
				else {
					for(int i=0;i<n;i++) {
						int idx = n-1;
						int[] temp = new int[n];
						for(int j=n-1;j>=0;j--) { 
							if(copyM[i][j]!=0) {
								if(temp[idx]==0) temp[idx] = copyM[i][j];
								else {
									if(temp[idx]==copyM[i][j]) temp[idx--] *= 2;
									else temp[--idx] = copyM[i][j];
								}
							}
						}
						for(int j=0;j<n;j++) {
							copyM[i][j] = temp[j];
						}
					}
				}
			}
			int cnt = 0;
			for(int i=0;i<n;i++) {
				for(int j=0;j<n;j++) {
					cnt = Math.max(cnt, copyM[i][j]);
				}
			}
			result = Math.max(result, cnt);
		}
		System.out.println(result);
	}
}

2. 1가지 방향을 기준으로 수행 (횟수 만큼 회전)  => 보완

import java.io.*;
import java.util.*;

public class Main {
	static int n;
	static int[][] map, copyM;
	public static void main(String[] args) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		StringTokenizer st;
		n = Integer.parseInt(br.readLine());
		map = new int[n][n];
		for(int i=0;i<n;i++) {
			st = new StringTokenizer(br.readLine());
			for(int j=0;j<n;j++) {
				map[i][j] = Integer.parseInt(st.nextToken());
			}
		}
		int total = (int)Math.pow(4, 5);
		int result = 0;
		for(int t=0;t<total;t++) {
			int mode = t;
			copyM = new int[n][n];
			for(int i=0;i<n;i++) {
				copyM[i] = map[i].clone();
			}
			for(int m=0;m<5;m++) {
				int rot = mode % 4;
				mode /= 4;
				rotate(rot);
				move();
			}
			int cnt = 0;
			for(int i=0;i<n;i++) {
				for(int j=0;j<n;j++) {
					if(copyM[i][j]>cnt) {
						cnt = copyM[i][j];
					}
				}
			}
			result = Math.max(result, cnt);
		}
		System.out.println(result);
	}
	private static void rotate(int rot) {
		int[][] temp = new int[n][n];
		for(int i=0;i<n;i++) {
			temp[i] = copyM[i].clone();
		}
		for(int i=0;i<n;i++) {
			for(int j=0;j<n;j++) {
				if(rot==1) copyM[i][j] = temp[n-1-j][i];
				if(rot==2) copyM[i][j] = temp[n-1-i][n-1-j];
				if(rot==3) copyM[i][j] = temp[j][n-1-i];
			}
		}
	}
	private static void move() {
		for(int i=0;i<n;i++) {
			int idx = 0;
			int[] temp = new int[n];
			for(int j=0;j<n;j++) {
				if(copyM[i][j]>0) {
					if(temp[idx]==0) temp[idx] = copyM[i][j];
					else {
						if(temp[idx]==copyM[i][j]) {
							temp[idx++] *= 2;
						}
						else if(temp[idx]!=copyM[i][j]) {
							temp[++idx] = copyM[i][j];
						}
					}
				}
			}
			copyM[i] = temp;
		}
	}
}