삼각 달팽이

package programmers;

import java.util.Arrays;

public class 삼각_달팽이 {

   public static int[] solution(int n) {
      if (n == 1)
         return new int[] {1};
      int[][] map = new int[n][n];

      int sum = getSum(n);

      int count = 1;
      int y = 0;
      int x = 0;
      int limit = 0;

      while (limit + 1 <= n / 2) {
         //y 증가
         while (y + limit < n && count <= sum) {
            if (map[y][x] != 0)
               break;
            map[y][x] = count++;
            y++;
         }
         y--;
         x++;
         //x 증가
         while (x + limit < n && count <= sum) {
            if (map[y][x] != 0)
               break;
            map[y][x] = count++;
            x++;
         }
         x -= 2;
         y--;
         //y , x 동시 감소
         while (y >= limit && x >= limit && count <= sum) {
            if (map[y][x] != 0)
               break;
            map[y][x] = count++;
            y--;
            x--;
         }
         y += 2;
         x++;
         limit++;
      }

      return getAnswer(n, map, sum);
   }

   private static int[] getAnswer(int n, int[][] map, int sum) {
      int[] answer = new int[sum];

      int idx = 0;
      for (int i = 0; i < n; i++) {
         for (int j = 0; j < n; j++) {
            if (map[i][j] == 0)
               break;
            answer[idx++] = map[i][j];
         }
      }

      return answer;
   }

   private static int getSum(int n) {
      int sum = 0;
      for (int i = 1; i <= n; i++) {
         sum += i;
      }

      return sum;
   }

   public static void main(String[] args) {
      System.out.println(Arrays.toString(solution(4)));
      System.out.println(Arrays.toString(solution(6)));
      System.out.println(Arrays.toString(solution(6)));
      System.out.println(Arrays.toString(solution(1)));
   }
}