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Generate random chess position: Difference between revisions
Added R language
(Added R language) |
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[' ', 'P', ' ', ' ', ' ', ' ', ' ', 'P']
</pre>
=={{header|R}}==
<lang R>
place_kings <- function(brd){
###
# Function that puts the two kings on the board
# and makes sure that they are not adjacent
###
while (TRUE) {
# generate positions for white and black kings
rank_white <- sample(1:8, 1) ; file_white <- sample(1:8, 1)
rank_black <- sample(1:8, 1) ; file_black <- sample(1:8, 1)
# compute the differences between ranks and files
diff_vec <- c(abs(rank_white - rank_black), abs(file_white - file_black))
# if the two kings are not adjacent, place them on the board
if (sum(diff_vec) > 2 | setequal(diff_vec, c(0,2))) {
brd[rank_white, file_white] <- "K"
brd[rank_black, file_black] <- "k"
break
}
}
return(brd)
}
pawn_on_promotion_square <- function(pc, pr){
###
# Function that checks whether a pawn is on a promotion square
# (such a situation is not possible in chess)
###
if (pc == "P" & pr == 1)
return(TRUE)
else if (pc == "p" & pr == 8)
return(TRUE)
else
return(FALSE)
}
populate_board <- function(brd, wp, bp){
###
# Function that puts pieces on the board making sure that they
# are not on the same squares, and verifying for pawn_on_promotion_square
###
# initialization
piece_list <- c("P", "N", "B", "R", "Q")
for (color in c("white", "black")){
# iterate for white (first) and black (after) pieces
if (color == "white"){
n_pieces = wp
pieces = piece_list
}
else {
n_pieces = bp
pieces = tolower(piece_list)
}
# place pieces one by one until we have them
while (n_pieces != 0){
piece_rank <- sample(1:8, 1) ; piece_file <- sample(1:8, 1)
piece <- sample(pieces, 1)
# check if square is empty and it is not a pawn on a promotion square
if (brd[piece_rank, piece_file] == " " & !pawn_on_promotion_square(piece, piece_rank)){
brd[piece_rank, piece_file] <- piece
n_pieces <- n_pieces - 1
}
}
}
return(brd)
}
fen_from_board <- function(brd){
###
# Function that prints out the FEN of a given input board
###
# create vector of positions by row
fen <- apply(brd, 1, function(x) {
r <- rle(x)
paste(ifelse(r$values == " ", r$lengths, r$values), collapse = "")
})
# paste them together with separator '/' and add the final string
fen <- paste(paste(fen, collapse = "/"), "w - - 0 1")
return(fen)
}
generate_fen <- function(){
###
# This function calls all the functions above and generates
# the board representation along with its FEN
###
# initialization
board <- matrix(" ", nrow = 8, ncol = 8)
# generate random amount of white and black pieces (kings excluded)
n_pieces_white <- sample(0:31, 1) ; n_pieces_black <- sample(0:31, 1)
# place kings on board
board <- place_kings(board)
# put other pieces on board
board <- populate_board(board, wp = n_pieces_white, bp = n_pieces_black)
# print board and FEN
print(board)
cat("\n")
cat(fen_from_board(board))
}
generate_fen()
</lang>
{{out}}
[,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8]
[1,] " " "R" "R" " " "n" "n" " " " "
[2,] "p" " " " " " " " " " " "k" "b"
[3,] " " " " "B" " " "p" " " "N" "r"
[4,] " " " " "N" "q" " " "q" "n" "q"
[5,] " " " " " " " " "b" " " " " " "
[6,] " " " " " " " " "q" "n" " " " "
[7,] " " " " " " " " "K" " " " " " "
[8,] " " "Q" "q" "R" "P" "b" " " " "
1R1n2/p5kb/2B1p1Nr/2Nq1qnq/4b3/4qn2/4K3/1QqRPb2 w - - 0 1
=={{header|Raku}}==
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