Chessboard in FEN
Description:
In the FEN (Forsyth-Edwards Notation), a chessboard is described as follows:
- The Board-Content is specified starting with the top row and ending with the bottom row.
- Character / is used to separate data of adjacent rows.
- Each row is specified from left to right.
- White pieces are identified by uppercase piece letters: PNBRQK.
- Black pieces are identified by lowercase piece letters: pnbrqk.
- Empty squares are represented by the numbers one through eight.
- A number used represents the count of contiguous empty squares along a row.
- Each row's sum of numbers and characters must equal 8.
For example:
- 5k1r/2q3p1/p3p2p/1B3p1Q/n4P2/6P1/bbP2N1P/1K1RR3
is the FEN notation description of the following chessboard:
The chessboard of the beginning of a chess game is described in FEN as:
- rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR
Your task is simple: given a chessboard description in a FEN notation you are asked to compute the number of unoccupied squares on the board which are not attacked by any piece.
Input:
Input is a sequence of lines, each line containing a FEN description of a chessboard. Note that the description does not necessarily give a legal chess position. Input lines do not contain whitespace.
Output:
For each line of input, output one line containing an integer which gives the number of unoccupied squares which are not attacked.
Sample Input:
5k1r/2q3p1/p3p2p/1B3p1Q/n4P2/6P1/bbP2N1P/1K1RR3 rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR
Sample Output:
3 16
Submit