Queen Attack

Instructions

Given the position of two queens on a chess board, indicate whether or not they are positioned so that they can attack each other.

In the game of chess, a queen can attack pieces which are on the same row, column, or diagonal.

A chessboard can be represented by an 8 by 8 array.

So if you are told the white queen is at c5 (zero-indexed at column 2, row 3) and the black queen at f2 (zero-indexed at column 5, row 6), then you know that the set-up is like so:

You are also able to answer whether the queens can attack each other. In this case, that answer would be yes, they can, because both pieces share a diagonal.

Credit

The chessboard image was made by habere-et-dispertire using LaTeX and the chessboard package by Ulrike Fischer.

A queen must be placed on a valid position on the board. Two queens cannot share the same position.

If a position has not been given, the queens are at their default starting positions. That's the bottom row (1) for the white queen and the top row (8) for the black queen. Both queens start in the fourth column (d).

  a b c d e f g h
8 _ _ _ B _ _ _ _ 8
7 _ _ _ _ _ _ _ _ 7
6 _ _ _ _ _ _ _ _ 6
5 _ _ _ _ _ _ _ _ 5
4 _ _ _ _ _ _ _ _ 4
3 _ _ _ _ _ _ _ _ 3
2 _ _ _ _ _ _ _ _ 2
1 _ _ _ W _ _ _ _ 1
  a b c d e f g h

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Source

J Dalbey's Programming Practice problems