// Piece.java -- define a piece class.  For now, it's just the rook
// and knight.  Can you find the bugs?  Why is there an infinite loop?

public class Piece
{
  private char rank;
  private int row;
  private int col;

  public Piece(char k, int r, int c)
  {
    rank = k;
    row = r;
    col = c;
  }

  // Infinite loop in this function.
  // ROOK -- go outward in 4 directions, up, down, left, right
  // for example, if we are at row = 2, col = 3
  //         1,3
  // 2,1 2,2 *** 2,4 2,5 2,6 2,7 2,8
  //         3,3
  //         4,3
  //         5,3
  //         6,3
  //         7,3
  //         8,3
  // Note that (row,col) is the current position of the rook
  // and that (r,c) is a possible destination. 
  public void findRookMoves()
  {
    int r, c;

    // go up
    for (r = row - 1; r >= 1; --r)
      System.out.println(r + "," + col);
  
    // go down
    for (r = row + 1; row <= 8; ++r)
      System.out.println(r + "," + col);

    // go left
    for (c = col - 1; col >= 1; --c)
      System.out.println(row + "," + c);

    // go right
    for (c = col + 1; col <= +8; ++c)
      System.out.println(row + "," + c);
  }

  // Infinite loop in this function.
  // KNIGHT -- go 2 up and 1 over, or some other combo of 2 and 1
  void findKnightMoves()
  {
    int i, j;

    for (i = 1; i <= 8; ++i)
      for (j = 1; j <= 8; ++i)
        if (two_and_one (i, j, row, col))
          System.out.println(i + "," + j);
  }

  // there are no bugs in this function -- it determines if
  // the square (row2, row2) can be reached by a knight from (row1, col1)
  public boolean two_and_one (int row1, int col1, int row2, int col2)
  {
    int row_diff, col_diff;

    row_diff = row1 - row2;
    if (row_diff < 0)
      row_diff = -row_diff;

    col_diff = col1 - col2;
    if (col_diff < 0)
      col_diff = -col_diff;

    if (row_diff == 2 && col_diff == 1 ||
        row_diff == 1 && col_diff == 2)
      return true;
    else
      return false;
  }
}