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Find Chess960 starting position identifier

From Rosetta Code
Task
Find Chess960 starting position identifier
You are encouraged to solve this task according to the task description, using any language you may know.

As described on the Chess960 page, Chess960 (a.k.a Fischer Random Chess, Chess9LX) is a variant of chess where the array of pieces behind the pawns is randomized at the start of the game to minimize the value of opening theory "book knowledge". That task is to generate legal starting positions, and some of the solutions accept a standard Starting Position Identifier number ("SP-ID"), and generate the corresponding position.

Task

This task is to go the other way: given a starting array of pieces (provided in any form that suits your implementation, whether string or list or array, of letters or Unicode chess symbols or enum values, etc.), derive its unique SP-ID. For example, given the starting array QNRBBNKR (or ♕♘♖♗♗♘♔♖ or ♛♞♜♝♝♞♚♜), your (sub)program should return 105; given the starting lineup of standard chess, it should return 518.

You may assume the input is a valid Chess960 position; detecting invalid input (including illegal characters or starting arrays with the bishops on the same color square or the king not between the two rooks) is optional.

Algorithm

The derivation is the inverse of the algorithm given at Wikipedia, and goes like this (we'll use the standard chess setup as an example):

1. Ignoring the Queen and Bishops, find the positions of the Knights within the remaining five spaces (in the standard array they're in the second and fourth positions), and then find the index number of that combination. There's a table at the above Wikipedia article, but it's just the possible positions sorted left to right and numbered 0 to 9: 0=NN---, 1=N-N--, 2=N--N-, 3=N---N, 4=-NN--, etc; our pair is combination number 5. Call this number N. N=5

2. Now ignoring the Knights (but including the Queen and Bishops), find the position of the Queen in the remaining 6 spaces; number them 0..5 from left to right and call the index of the Queen's position Q. In our example, Q=2.

3. Finally, find the positions of the two bishops within their respective sets of four like-colored squares. It's important to note here that the board in chess is placed such that the leftmost position on the home row is on a dark square and the rightmost a light. So if we number the squares of each color 0..3 from left to right, the dark bishop in the standard position is on square 1 (D=1), and the light bishop is on square 2 (L=2).

4. Then the position number is given by 4(4(6N + Q)+D)+L, which reduces to 96N + 16Q + 4D + L. In our example, that's 96×5 + 16×2 + 4×1 + 2 = 480 + 32 + 4 + 2 = 518.

BASIC[edit]

Commodore BASIC[edit]

Works with: Commodore BASIC version 2.0

Unlike the solution for the reverse task, which uses DO/LOOP and so requires at least Commodore BASIC 3.5, this should work on any version.

100 REM DERIVE SP-ID FROM CHESS960 POS
110 PRINT "ENTER START ARRAY AS SEEN BY WHITE."
120 PRINT: PRINT "STARTING ARRAY:";
130 OPEN 1,0: INPUT#1, AR$: CLOSE 1: PRINT
140 IF LEN(AR$)=0 THEN END
150 IF LEN(AR$)=8 THEN 170
160 PRINT "ARRAY MUST BE 8 PIECES.": GOTO 120
170 FOR I=1 TO 8
180 : P$=MID$(AR$,I,1)
190 : IF P$="Q" THEN Q(Q)=I: Q=Q+1: GOTO 250
200 : IF P$="K" THEN K(K)=I: K=K+1: GOTO 250
210 : IF P$="B" THEN B(B)=I: B=B+1: GOTO 250
220 : IF P$="N" THEN N(N)=I: N=N+1: GOTO 250
230 : IF P$="R" THEN R(R)=I: R=R+1: GOTO 250
240 : PRINT "ILLEGAL PIECE '"P$"'.": GOTO 120
250 NEXT I
260 IF K<>1 THEN PRINT "THERE MUST BE EXACTLY ONE KING.": GOTO 120
270 IF Q<>1 THEN PRINT "THERE MUST BE EXACTLY ONE QUEEN.": GOTO 120
280 IF B<>2 THEN PRINT "THERE MUST BE EXACTLY TWO BISHOPS.": GOTO 120
290 IF N<>2 THEN PRINT "THERE MUST BE EXACTLY TWO KNIGHTS.": GOTO 120
300 IF R<>2 THEN PRINT "THERE MUST BE EXACTLY TWO ROOKS.": GOTO 120
310 IF (K(0) > R(0)) AND (K(0) < R(1)) THEN 330
320 PRINT "KING MUST BE BETWEEN THE ROOKS.": GOTO 120
330 IF (B(0) AND 1) <> (B(1) AND 1) THEN 350
340 PRINT "BISHOPS MUST BE ON OPPOSITE COLORS.": GOTO 120
350 FOR I=0 TO 1
360 : N=N(I)
370 : IF N(I)>Q(I) THEN N=N-1
380 : FOR J=0 TO 1
390 : IF N(I)>B(J) THEN N=N-1
400 : NEXT J
410 : N(I)=N
420 NEXT I
430 N0=1: N1=2
440 FOR N=0 TO 9
450 : IF N0=N(0) AND N1=N(1) THEN 490
460 : N1=N1+1
470 : IF N1>5 THEN N0=N0+1: N1=N0+1
480 NEXT N
490 Q=Q(0)-1
500 FOR I=0 TO 1
510 : IF Q(0)>N(I) THEN Q=Q-1
520 NEXT I
530 FOR I=0 TO 1
540 : B=B(I)-1
550 : IF B AND 1 THEN L=INT(B/2)
560 : IF (B AND 1)=0 THEN D=B/2
570 NEXT I
580 PRINT "SPID ="; 96*N+16*Q+4*D+L
Output:
READY.
RUN
ENTER START ARRAY AS SEEN BY WHITE.

STARTING ARRAY:RNBQKBNR
SPID = 518

READY.
RUN
ENTER START ARRAY AS SEEN BY WHITE.

STARTING ARRAY:QNRBBNKR
SPID = 105

READY.

Factor[edit]

Works with: Factor version 0.99 2021-06-02
USING: assocs assocs.extras combinators formatting kernel
literals math math.combinatorics sequences sequences.extras sets
strings ;
 
 
! ====== optional error-checking ======
 
: check-length ( str -- )
length 8 = [ "Must have 8 pieces." throw ] unless ;
 
: check-one ( str -- )
"KQ" counts [ nip 1 = not ] assoc-find nip
[ 1string "Must have one %s." sprintf throw ] [ drop ] if ;
 
: check-two ( str -- )
"BNR" counts [ nip 2 = not ] assoc-find nip
[ 1string "Must have two %s." sprintf throw ] [ drop ] if ;
 
: check-king ( str -- )
"QBN" without "RKR" =
[ "King must be between rooks." throw ] unless ;
 
: check-bishops ( str -- )
CHAR: B swap indices sum odd?
[ "Bishops must be on opposite colors." throw ] unless ;
 
: check-sp ( str -- )
{
[ check-length ]
[ check-one ]
[ check-two ]
[ check-king ]
[ check-bishops ]
} cleave ;
 
! ====== end optional error-checking ======
 
 
CONSTANT: convert $[ "RNBQK" "♖♘♗♕♔" zip ]
 
CONSTANT: table $[ "NN---" all-unique-permutations ]
 
: knightify ( str -- newstr )
[ dup CHAR: N = [ drop CHAR: - ] unless ] map ;
 
: n ( str -- n ) "QB" without knightify table index ;
 
: q ( str -- q ) "N" without CHAR: Q swap index ;
 
: d ( str -- d ) CHAR: B swap <evens> index ;
 
: l ( str -- l ) CHAR: B swap <odds> index ;
 
: sp-id ( str -- n )
dup check-sp
{ [ n 96 * ] [ q 16 * + ] [ d 4 * + ] [ l + ] } cleave ;
 
: sp-id. ( str -- )
dup [ convert substitute ] [ sp-id ] bi
"%s / %s: %d\n" printf ;
 
"QNRBBNKR" sp-id.
"RNBQKBNR" sp-id.
Output:
QNRBBNKR / ♕♘♖♗♗♘♔♖: 105
RNBQKBNR / ♖♘♗♕♔♗♘♖: 518

Go[edit]

Translation of: Wren
package main
 
import (
"fmt"
"log"
"strings"
)
 
var glyphs = []rune("♜♞♝♛♚♖♘♗♕♔")
var names = map[rune]string{'R': "rook", 'N': "knight", 'B': "bishop", 'Q': "queen", 'K': "king"}
var g2lMap = map[rune]string{
'♜': "R", '♞': "N", '♝': "B", '♛': "Q", '♚': "K",
'♖': "R", '♘': "N", '♗': "B", '♕': "Q", '♔': "K",
}
 
var ntable = map[string]int{"01": 0, "02": 1, "03": 2, "04": 3, "12": 4, "13": 5, "14": 6, "23": 7, "24": 8, "34": 9}
 
func g2l(pieces string) string {
lets := ""
for _, p := range pieces {
lets += g2lMap[p]
}
return lets
}
 
func spid(pieces string) int {
pieces = g2l(pieces) // convert glyphs to letters
 
/* check for errors */
if len(pieces) != 8 {
log.Fatal("There must be exactly 8 pieces.")
}
for _, one := range "KQ" {
count := 0
for _, p := range pieces {
if p == one {
count++
}
}
if count != 1 {
log.Fatalf("There must be one %s.", names[one])
}
}
for _, two := range "RNB" {
count := 0
for _, p := range pieces {
if p == two {
count++
}
}
if count != 2 {
log.Fatalf("There must be two %s.", names[two])
}
}
r1 := strings.Index(pieces, "R")
r2 := strings.Index(pieces[r1+1:], "R") + r1 + 1
k := strings.Index(pieces, "K")
if k < r1 || k > r2 {
log.Fatal("The king must be between the rooks.")
}
b1 := strings.Index(pieces, "B")
b2 := strings.Index(pieces[b1+1:], "B") + b1 + 1
if (b2-b1)%2 == 0 {
log.Fatal("The bishops must be on opposite color squares.")
}
 
/* compute SP_ID */
piecesN := strings.ReplaceAll(pieces, "Q", "")
piecesN = strings.ReplaceAll(piecesN, "B", "")
n1 := strings.Index(piecesN, "N")
n2 := strings.Index(piecesN[n1+1:], "N") + n1 + 1
np := fmt.Sprintf("%d%d", n1, n2)
N := ntable[np]
 
piecesQ := strings.ReplaceAll(pieces, "N", "")
Q := strings.Index(piecesQ, "Q")
 
D := strings.Index("0246", fmt.Sprintf("%d", b1))
L := strings.Index("1357", fmt.Sprintf("%d", b2))
if D == -1 {
D = strings.Index("0246", fmt.Sprintf("%d", b2))
L = strings.Index("1357", fmt.Sprintf("%d", b1))
}
 
return 96*N + 16*Q + 4*D + L
}
 
func main() {
for _, pieces := range []string{"♕♘♖♗♗♘♔♖", "♖♘♗♕♔♗♘♖"} {
fmt.Printf("%s or %s has SP-ID of %d\n", pieces, g2l(pieces), spid(pieces))
}
}
Output:
♕♘♖♗♗♘♔♖ or QNRBBNKR has SP-ID of 105
♖♘♗♕♔♗♘♖ or RNBQKBNR has SP-ID of 518

Julia[edit]

const whitepieces = "♖♘♗♕♔♗♘♖♙"
const whitechars = "rnbqkp"
const blackpieces = "♜♞♝♛♚♝♞♜♟"
const blackchars = "RNBQKP"
const piece2ascii = Dict(zip("♖♘♗♕♔♗♘♖♙♜♞♝♛♚♝♞♜♟", "rnbqkbnrpRNBQKBNRP"))
 
""" Derive a chess960 position's SP-ID from its string representation. """
function chess960spid(position::String = "♖♘♗♕♔♗♘♖", errorchecking = true)
if errorchecking
@assert length(position) == 8 "Need exactly 8 pieces"
@assert all(p -> p in whitepieces || p in blackpieces, position) "Invalid piece character"
@assert all(p -> p in whitepieces, position) || all(p -> p in blackpieces, position) "Side of pieces is mixed"
@assert all(p -> !(p in "♙♟"), position) "No pawns allowed"
end
a = uppercase(String([piece2ascii[c] for c in position]))
 
if errorchecking
@assert all(p -> count(x -> x == p, a) == 1, "KQ") "Need exactly one of each K and Q"
@assert all(p -> count(x -> x == p, a) == 2, "RNB") "Need exactly 2 of each R, N, B"
@assert findfirst(p -> p == 'R', a) < findfirst(p -> p == 'K', a) < findlast(p -> p == 'R', a) "King must be between rooks"
@assert isodd(findfirst(p -> p == 'B', a) + findlast(p -> p == 'B', a)) "Bishops must be on different colors"
end
 
knighttable = [12, 13, 14, 15, 23, 24, 25, 34, 35, 45]
noQB = replace(a, r"[QB]" => "")
knightpos1, knightpos2 = findfirst(c -> c =='N', noQB), findlast(c -> c =='N', noQB)
N = findfirst(s -> s == 10 * knightpos1 + knightpos2, knighttable) - 1
Q = findfirst(c -> c == 'Q', replace(a, "N" => "")) - 1
bishoppositions = [findfirst(c -> c =='B', a), findlast(c -> c =='B', a)]
if isodd(bishoppositions[2])
bishoppositions = reverse(bishoppositions) # dark color bishop first
end
D, L = bishoppositions[1] ÷ 2, bishoppositions[2] ÷ 2 - 1
 
return 96N + 16Q + 4D + L
end
 
for position in ["♕♘♖♗♗♘♔♖", "♖♘♗♕♔♗♘♖"]
println(collect(position), " => ", chess960spid(position))
end
 
Output:
['♕', '♘', '♖', '♗', '♗', '♘', '♔', '♖'] => 105
['♖', '♘', '♗', '♕', '♔', '♗', '♘', '♖'] => 518

Nim[edit]

Translation of: Wren
import sequtils, strformat, strutils, sugar, tables, unicode
 
type Piece {.pure.} = enum Rook = "R", Knight = "N", Bishop = "B", Queen = "Q", King = "K"
 
const
GlypthToPieces = {"♜": Rook, "♞": Knight, "♝": Bishop, "♛": Queen, "♚": King,
"♖": Rook, "♘": Knight, "♗": Bishop, "♕": Queen, "♔": King}.toTable
Names = [Rook: "rook", Knight: "knight", Bishop: "bishop", Queen: "queen", King: "king"]
NTable = {[0, 1]: 0, [0, 2]: 1, [0, 3]: 2, [0, 4]: 3, [1, 2]: 4,
[1, 3]: 5, [1, 4]: 6, [2, 3]: 7, [2, 4]: 8, [3, 4]: 9}.toTable
 
func toPieces(glyphs: string): seq[Piece] =
collect(newSeq, for glyph in glyphs.runes: GlypthToPieces[glyph.toUTF8])
 
func isEven(n: int): bool = (n and 1) == 0
 
func positions(pieces: seq[Piece]; piece: Piece): array[2, int] =
var idx = 0
for i, p in pieces:
if p == piece:
result[idx] = i
inc idx
 
func spid(glyphs: string): int =
 
let pieces = glyphs.toPieces()
 
# Check for errors.
if pieces.len != 8:
raise newException(ValueError, "there must be exactly 8 pieces.")
for piece in [King, Queen]:
if pieces.count(piece) != 1:
raise newException(ValueError, &"there must be one {Names[piece]}.")
for piece in [Rook, Knight, Bishop]:
if pieces.count(piece) != 2:
raise newException(ValueError, &"there must be two {Names[piece]}s.")
let r = pieces.positions(Rook)
let k = pieces.find(King)
if k < r[0] or k > r[1]:
raise newException(ValueError, "the king must be between the rooks.")
var b = pieces.positions(Bishop)
if isEven(b[1] - b[0]):
raise newException(ValueError, "the bishops must be on opposite color squares.")
 
# Compute SP_ID.
let piecesN = pieces.filterIt(it notin [Queen, Bishop])
let n = NTable[piecesN.positions(Knight)]
 
let piecesQ = pieces.filterIt(it != Knight)
let q = piecesQ.find(Queen)
 
if b[1].isEven: swap b[0], b[1]
let d = [0, 2, 4, 6].find(b[0])
let l = [1, 3, 5, 7].find(b[1])
 
result = 96 * n + 16 * q + 4 * d + l
 
 
for glyphs in ["♕♘♖♗♗♘♔♖", "♖♘♗♕♔♗♘♖"]:
echo &"{glyphs} or {glyphs.toPieces().join()} has SP-ID of {glyphs.spid()}"
Output:
♕♘♖♗♗♘♔♖ or QNRBBNKR has SP-ID of 105
♖♘♗♕♔♗♘♖ or RNBQKBNR has SP-ID of 518

Perl[edit]

Translation of: Raku
use strict;
use warnings;
use feature 'say';
use List::AllUtils 'indexes';
 
sub sp_id {
my $setup = shift // 'RNBQKBNR';
 
8 == length $setup or die 'Illegal position: should have exactly eight pieces';
1 == @{[ $setup =~ /$_/g ]} or die "Illegal position: should have exactly one $_" for <K Q>;
2 == @{[ $setup =~ /$_/g ]} or die "Illegal position: should have exactly two $_\'s" for <B N R>;
$setup =~ m/R .* K .* R/x or die 'Illegal position: King not between rooks.';
index($setup,'B')%2 != rindex($setup,'B')%2 or die 'Illegal position: Bishops not on opposite colors.';
 
my @knights = indexes { 'N' eq $_ } split '', $setup =~ s/[QB]//gr;
my $knight = indexes { join('', @knights) eq $_ } <01 02 03 04 12 13 14 23 24 34>; # combinations(5,2)
my @bishops = indexes { 'B' eq $_ } split '', $setup;
my $dark = int ((grep { $_ % 2 == 0 } @bishops)[0]) / 2;
my $light = int ((grep { $_ % 2 == 1 } @bishops)[0]) / 2;
my $queen = index(($setup =~ s/B//gr), 'Q');
 
int 4*(4*(6*$knight + $queen)+$dark)+$light;
}
 
say "$_ " . sp_id($_) for <QNRBBNKR RNBQKBNR>;
Output:
QNRBBNKR 105
RNBQKBNR 518

Phix[edit]

with javascript_semantics
function spid(string s)
    if sort(s)!="BBKNNQRR" then return -1 end if
    if filter(s,"in","RK")!="RKR" then return -1 end if
    sequence b = find_all('B',s)
    if even(sum(b)) then return -1 end if
    integer {n1,n2} = find_all('N',filter(s,"out","QB")),
            N = {-2,1,3,4}[n1]+n2,
            Q = find('Q',filter(s,"!=",'N'))-1,
            D = filter(b,odd)[1]-1, -- (nb not /2)
            L = filter(b,even)[1]/2-1
    return 96*N + 16*Q + 2*D + L
end function

procedure test(string s)
    printf(1,"%s : %d\n",{s,spid(s)})
end procedure

test("QNRBBNKR")
test("RNBQKBNR")
Output:
QNRBBNKR : 105
RNBQKBNR : 518

To support all those crazy unicode characters just change the start of spid() to:

function spid(string u)
    sequence u32 = utf8_to_utf32(u),
             c32 = utf8_to_utf32("♜♞♝♛♚♖♘♗♕♔"),
             s32 = substitute_all(u32,c32,"RNBQKRNBQK")
    string s = utf32_to_utf8(s32)

--... and add:
test("♕♘♖♗♗♘♔♖")
test("♖♘♗♕♔♗♘♖")
Output:

Note that output on a windows terminal is as expected far from pretty, this is from pwa/p2js

QNRBBNKR : 105
RNBQKBNR : 518
♕♘♖♗♗♘♔♖ : 105
♖♘♗♕♔♗♘♖ : 518

Raku[edit]

#!/usr/bin/env raku
# derive a chess960 position's SP-ID
unit sub MAIN($array = "♖♘♗♕♔♗♘♖");
 
# standardize on letters for easier processing
my $ascii = $array.trans("♜♞♝♛♚♖♘♗♕♔" => "RNBQKRNBQK");
 
# (optional error-checking)
if $ascii.chars != 8 {
die "Illegal position: should have exactly eight pieces\n";
}
 
for «K Q» -> $one {
if +$ascii.indices($one) != 1 {
die "Illegal position: should have exactly one $one\n";
}
}
 
for «B N R» -> $two {
if +$ascii.indices($two) != 2 {
die "Illegal position: should have exactly two $two\'s\n";
}
}
 
if $ascii !~~ /'R' .* 'K' .* 'R'/ {
die "Illegal position: King not between rooks.";
}
 
if [+]($ascii.indices('B').map(* % 2)) != 1 {
die "Illegal position: Bishops not on opposite colors.";
}
# (end optional error-checking)
 
# Work backwards through the placement rules.
# King and rooks are forced during placement, so ignore them.
 
# 1. Figure out which knight combination was used:
my @knights = $ascii
.subst(/<[QB]>/,'',:g)
.indices('N');
 
my $knight = combinations(5,2).kv.grep(
-> $i,@c { @c eq @knights }
)[0][0];
 
# 2. Then which queen position:
my $queen = $ascii
.subst(/<[B]>/,'',:g)
.index('Q');
 
# 3. Finally the two bishops:
my @bishops = $ascii.indices('B');
my $dark = @bishops.grep({ $_ %% 2 })[0] div 2;
my $light = @bishops.grep({ not $_ %% 2 })[0] div 2;
 
my $sp-id = 4*(4*(6*$knight + $queen)+$dark)+$light;
 
# standardize output
my $display = $ascii.trans("RNBQK" => "♖♘♗♕♔");
 
say "$display: $sp-id";
Output:
$ c960spid QNRBBNKR
♕♘♖♗♗♘♔♖: 105
$ c960spid
♖♘♗♕♔♗♘♖: 518

Ruby[edit]

def chess960_to_spid(pos)
start_str = pos.tr("♖♘♗♕♔", "RNBQK")
#1 knights score
s = start_str.delete("QB")
n = [0,1,2,3,4].combination(2).to_a.index( [s.index("N"), s.rindex("N")] )
#2 queen score
q = start_str.delete("N").index("Q")
#3 bishops
bs = start_str.index("B"), start_str.rindex("B")
d = bs.detect(&:even?).div(2)
l = bs.detect(&:odd? ).div(2)
 
96*n + 16*q + 4*d + l
end
 
positions = ["QNRBBNKR", "♖♘♗♕♔♗♘♖"]
positions.each{|pos| puts "#{pos}: #{chess960_to_spid(pos)}" }
 
Output:
QNRBBNKR:  105
♖♘♗♕♔♗♘♖:  518

Wren[edit]

Library: Wren-trait
import "/trait" for Indexed
 
var glyphs = "♜♞♝♛♚♖♘♗♕♔".toList
var letters = "RNBQKRNBQK"
var names = { "R": "rook", "N": "knight", "B": "bishop", "Q": "queen", "K": "king" }
var g2lMap = {}
for (se in Indexed.new(glyphs)) g2lMap[glyphs[se.index]] = letters[se.index]
 
var g2l = Fn.new { |pieces| pieces.reduce("") { |acc, p| acc + g2lMap[p] } }
 
var ntable = { "01":0, "02":1, "03":2, "04":3, "12":4, "13":5, "14":6, "23":7, "24":8, "34":9 }
 
var spid = Fn.new { |pieces|
pieces = g2l.call(pieces) // convert glyphs to letters
 
/* check for errors */
if (pieces.count != 8) Fiber.abort("There must be exactly 8 pieces.")
for (one in "KQ") {
if (pieces.count { |p| p == one } != 1 ) Fiber.abort("There must be one %(names[one]).")
}
for (two in "RNB") {
if (pieces.count { |p| p == two } != 2 ) Fiber.abort("There must be two %(names[two])s.")
}
var r1 = pieces.indexOf("R")
var r2 = pieces.indexOf("R", r1 + 1)
var k = pieces.indexOf("K")
if (k < r1 || k > r2) Fiber.abort("The king must be between the rooks.")
var b1 = pieces.indexOf("B")
var b2 = pieces.indexOf("B", b1 + 1)
if ((b2 - b1) % 2 == 0) Fiber.abort("The bishops must be on opposite color squares.")
 
/* compute SP_ID */
var piecesN = pieces.replace("Q", "").replace("B", "")
var n1 = piecesN.indexOf("N")
var n2 = piecesN.indexOf("N", n1 + 1)
var np = "%(n1)%(n2)"
var N = ntable[np]
 
var piecesQ = pieces.replace("N", "")
var Q = piecesQ.indexOf("Q")
 
var D = "0246".indexOf(b1.toString)
var L = "1357".indexOf(b2.toString)
if (D == -1) {
D = "0246".indexOf(b2.toString)
L = "1357".indexOf(b1.toString)
}
 
return 96*N + 16*Q + 4*D + L
}
 
for (pieces in ["♕♘♖♗♗♘♔♖", "♖♘♗♕♔♗♘♖"]) {
System.print("%(pieces) or %(g2l.call(pieces)) has SP-ID of %(spid.call(pieces))")
}
Output:
♕♘♖♗♗♘♔♖ or QNRBBNKR has SP-ID of 105
♖♘♗♕♔♗♘♖ or RNBQKBNR has SP-ID of 518