[Java] 삼각 달팽이 (2차원배열, 방향)

2023.07.19 - [Coding Test/programmers] - 삼각 달팽이 (리스트 반시계 방향으로 채우기)

삼각 달팽이 (리스트 반시계 방향으로 채우기)

 

import java.util.*;

class Solution {
    public int[] solution(int n) {
        
        int[][] triangle = new int[n][n];
        int v=1; // 현재수
        int r=0;
        int c=0;
        
        for (int d=0; d<n; d++){
            for (int x=0; x<n-d; x++){
                switch((d+1)%3){
                    case 0:  r--; c--;
                        break;
                    case 1: r++; 
                        break;
                    case 2: c++;
                        break;
                }
                triangle[r-1][c]=v++;
            } 
        }
                
        int[] answer = new int[v-1];
        int idx = 0;
        for (int i=0; i<n; i++){
            for (int j=0; j<=i; j++){
                if(triangle[i][j]!=0){
                    answer[idx++]=triangle[i][j];
                }
            }
        }
        return answer;
    }
}

import java.util.*;

class Solution {
    public static final int[] dx = {0,1,-1};
    public static final int[] dy = {1,0,-1};
    
    public int[] solution(int n) {
        
        int[][] triangle = new int[n][n];
        int v=1; // 현재수
        int x=0;
        int y=0;
        int d=0; 
        
        
        while(true){
            triangle[y][x]=v++;
            
            int nx = x+dx[d];
            int ny = y+dy[d];
            if(nx==n||nx==-1||ny==n||ny==-1||triangle[ny][nx]!=0) {
                d=(d+1)%3;
                nx = x+dx[d];
                ny = y+dy[d];
                if(nx==n||nx==-1||ny==n||ny==-1||triangle[ny][nx]!=0) break;
            }
            x = nx;
            y = ny;
         }
                
        int[] answer = new int[v-1];
        int idx = 0;
        for (int i=0; i<n; i++){
            for (int j=0; j<=i; j++){
                if(triangle[i][j]!=0){
                    answer[idx++]=triangle[i][j];
                }
            }
        }
        return answer;
    }
}