HackerRank matrix rotation - Google semchyshyn - study code - Java Solution - calculation is interesting.

matrixRotation_gg_semchyshyn.java

import java.util.*;

public class Solution {
  public static void main(String[] args) {
    int m, n, r, a[][];
    try (Scanner in = new Scanner(System.in)) {
      m = in.nextInt();
      n = in.nextInt();
      r = in.nextInt();
      a = new int[m][];
      for (int i = 0; i < m; i++) {
        a[i] = new int[n];
        for (int j = 0; j < n; j++) {
          a[i][j] = in.nextInt();
        }
      }
    }
    for (int i = 0; i < m; i++) {
      for (int j = 0; j < n; j++) {
        if (j > 0) {
          System.out.print(' ');
        }
        int layer = Math.min(Math.min(i, j), Math.min(m - i - 1, n - j - 1));
        int length = 2*n + 2*m - 8*layer - 4;
        int position = i == layer ? j - layer :
               n - j - 1 == layer ? n + i - 3*layer - 1 :
               m - i - 1 == layer ? m + 2*n - j - 5*layer - 3 :
                                    2*m + 2*n - 7*layer - i - 4;
        int rotated = (position + r) % length;
        int value = rotated < n - 2*layer           ? a[layer][rotated + layer] :
                    rotated < m + n - 4*layer - 1   ? a[rotated - n + 3*layer + 1][n - layer - 1] :
                    rotated < m + 2*n - 6*layer - 2 ? a[m - layer - 1][m + 2*n - 5*layer - 3 - rotated] : 
                                                      a[2*m + 2*n - 7*layer - 4 - rotated][layer];
        System.out.print(value);
      }
      System.out.println();
    }
  }
}