Problem 61155. FEN to Chess Board

Ned Gulley

5 solvers

0 likes

Solve

Solve Later

Note: This problem is the reverse, or complement, of Problem 61144 - FEN Chess Notation.
Given a FEN (Forsyth-Edwards Notation) string representing a chess board position, convert it to an 8-by-8 character matrix.
FEN notation encodes each rank (row) from top to bottom, separated by slashes (`/`). Numbers 1-8 represent consecutive empty squares.
The output matrix uses:
Dots (`.`) for empty squares
Letters for pieces: `rnbqkp` (black pieces) and `RNBQKP` (white pieces)
If the FEN string contains additional fields (castling rights, en passant, etc.), ignore everything after the first space and only parse the board position.
Example 1
Starting position.
Input: 'rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR'
Output:
['rnbqkbnr';
 'pppppppp';
 '........';
 '........';
 '........';
 '........';
 'PPPPPPPP';
 'RNBQKBNR']
Example 2
After white plays e4:
Input: 'rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR'
Output:
['rnbqkbnr';
 'pppppppp';
 '........';
 '........';
 '....P...';
 '........';
 'PPPP.PPP';
 'RNBQKBNR']
Note: The `4P3` means 4 empty squares, then P, then 3 empty squares.