Spiral matrix print - March 7 2018 - I am the interviewer and the peer solved the problem. The code should be improved.

SpiralMatrixPrint_March7_2018.java

/*
Spiral Matrix print - mock interview, it took the peer over 45 minutes to come out the correct solution. 
 Given a matrix of m x n elements (m rows, n columns), return all elements of the matrix in spiral order. For example, Given the following matrix: 
[
  [ 1, 2, 3 ],
  [ 4, 5, 6 ],
  [ 7, 8, 9 ]
]
You should return [1,2,3,6,9,8,7,4,5].
  
 */

class Solution {
    
    public int[] spiralOrder(int[][] matrix) {
        int rows, cols;
        if((rows = matrix.length) == 0 || (cols = matrix[0].length) == 0) {
            return new int[0];
        }
        boolean[][] flags = new boolean[rows][cols];
        int[] result = new int[rows * cols];
        int[][] directions = {{0, 1}, {1, 0}, {0, -1}, {-1, 0}}; // right, down, left, up
        int index = 0;
        int r = 0;  // current row
        int c = 0;  // current col
        while(index < result.length) {
            for(int i = 0; i < directions.length; i++) {  // no break statement inside !
                int[] delta = directions[i];
                while(r >= 0 && r < rows && c >= 0 && c < cols && !flags[r][c]) {
                    result[index++] = matrix[r][c];
                    flags[r][c] = true;

                    int nr = r + delta[0];
                    int nc = c + delta[1];
                    if(nr >= 0 && nr < rows && nc >= 0 && nc < cols && !flags[nr][nc]) {
                        r = nr;
                        c = nc;
                    }
                }
                int[] nextDir = directions[(i+1) % directions.length];
                r += nextDir[0];
                c += nextDir[1];
            }
        }
        return result;
    }
    
    public void printArray(int[] arr) {
        for(int i : arr) {
            System.out.print(" " + i);
        }
        System.out.println();
    }
    
    public static void main(String[] args) {
        Solution inst = new Solution();
        int[][] matrix = {{1, 2, 3, 10}, {4, 5, 6, 11}, {7, 8, 9, 12}};
        int[] res = inst.spiralOrder(matrix);
        inst.printArray(res);
      
    }
}