June 2018 Update

Task/Generate-Chess960-starting-position/00DESCRIPTION

@@ -1,4 +1,4 @@
-'''[[wp:Chess960|Chess960]]'''   is a variant of chess created by world champion [[wp:Bobby Fischer|Bobby Fischer]].  Unlike other variants of the game, Chess960 does not require a different material, but instead relies on a random initial position, with a few constraints:
+'''[[wp:Chess960|Chess960]]''' is a variant of chess created by world champion [[wp:Bobby Fischer|Bobby Fischer]].  Unlike other variants of the game, Chess960 does not require a different material, but instead relies on a random initial position, with a few constraints:
 
 * as in the standard chess game, all eight white pawns must be placed on the second rank.
 * White pieces must stand on the first rank as in the standard game, in random column order but with the two following constraints:
@@ -11,5 +11,5 @@ With those constraints there are '''960''' possible starting positions, thus the
 
 
 ;Task:
-The purpose of this task is to write a program that can randomly generate any one of the 960 Chess960 initial positions.   You will show the result as the first rank displayed with   [[wp:Chess symbols in Unicode|Chess symbols in Unicode: ♔♕♖♗♘]]   or with the letters   '''K'''ing   '''Q'''ueen   '''R'''ook   '''B'''ishop   k'''N'''ight.
+The purpose of this task is to write a program that can randomly generate any one of the 960 Chess960 initial positions. You will show the result as the first rank displayed with [[wp:Chess symbols in Unicode|Chess symbols in Unicode: ♔♕♖♗♘]] or with the letters '''K'''ing '''Q'''ueen '''R'''ook '''B'''ishop k'''N'''ight.
 <br><br>

Task/Generate-Chess960-starting-position/C/generate-chess960-starting-position.c

@@ -0,0 +1,104 @@
+/*Abhishek Ghosh, 10th October 2017*/
+
+#include<stdlib.h>
+#include<locale.h>
+#include<wchar.h>
+#include<stdio.h>
+#include<time.h>
+
+char rank[9];
+
+int pos[8];
+
+void swap(int i,int j){
+	int temp = pos[i];
+	pos[i] = pos[j];
+	pos[j] = temp;
+}
+
+void generateFirstRank(){
+	 int kPos,qPos,bPos1,bPos2,rPos1,rPos2,nPos1,nPos2,i;
+	
+	 for(i=0;i<8;i++){
+		 rank[i] = 'e';
+		 pos[i] = i;
+	 }
+		
+	 do{
+		 kPos = rand()%8;
+		 rPos1 = rand()%8;
+		 rPos2 = rand()%8;
+	 }while((rPos1-kPos<=0 && rPos2-kPos<=0)||(rPos1-kPos>=0 && rPos2-kPos>=0)||(rPos1==rPos2 || kPos==rPos1 || kPos==rPos2));
+
+	 rank[pos[rPos1]] = 'R';
+	 rank[pos[kPos]] = 'K';
+	 rank[pos[rPos2]] = 'R';
+	
+	 swap(rPos1,7);
+	 swap(rPos2,6);
+	 swap(kPos,5);
+	
+	 do{
+		 bPos1 = rand()%5;
+		 bPos2 = rand()%5;
+	 }while(((pos[bPos1]-pos[bPos2])%2==0)||(bPos1==bPos2));
+
+	 rank[pos[bPos1]] = 'B';
+	 rank[pos[bPos2]] = 'B';
+	
+	 swap(bPos1,4);
+	 swap(bPos2,3);
+	
+	 do{
+		 qPos = rand()%3;
+		 nPos1 = rand()%3;
+	 }while(qPos==nPos1);
+	
+	 rank[pos[qPos]] = 'Q';
+	 rank[pos[nPos1]] = 'N';
+	
+	 for(i=0;i<8;i++)
+		 if(rank[i]=='e'){
+			 rank[i] = 'N';
+			 break;
+		 }		
+}
+
+void printRank(){
+	int i;
+	
+	#ifdef _WIN32
+		printf("%s\n",rank);
+	#else
+	{
+		setlocale(LC_ALL,"");
+		printf("\n");
+		for(i=0;i<8;i++){
+			if(rank[i]=='K')
+				printf("%lc",(wint_t)9812);
+			else if(rank[i]=='Q')
+				printf("%lc",(wint_t)9813);
+			else if(rank[i]=='R')
+				printf("%lc",(wint_t)9814);
+			else if(rank[i]=='B')
+				printf("%lc",(wint_t)9815);
+			if(rank[i]=='N')
+				printf("%lc",(wint_t)9816);
+		}
+	}
+	#endif
+}
+
+int main()
+{
+	int i;
+	
+	srand((unsigned)time(NULL));
+	
+	for(i=0;i<9;i++){
+		generateFirstRank();
+		printRank();
+	}
+	
+	return 0;
+}

Task/Generate-Chess960-starting-position/Julia/generate-chess960-starting-position.julia

@@ -1,30 +1,30 @@
-# placeholder knights
-rank1 = ['♘', '♘', '♘', '♘', '♘', '♘', '♘', '♘']
+function generateposition()
+    # Placeholder knights
+    rank = ['♘', '♘', '♘', '♘', '♘', '♘', '♘', '♘']
+    lrank = length(rank)
 
-# function to check if a space is available
-isfree(x::Int) = rank1[x] == '♘'
+    # Check if a space is available
+    isfree(x::Int) = rank[x] == '♘'
 
-# place king
-king = rand(2:7)
-rank1[king] = '♔'
+    # Place the King
+    rank[indking = rand(2:lrank-1)] = '♔'
 
-# place rooks
-rook1 = rand(filter(isfree, 1:8))
-rank1[rook1] = '♖'
+    # Place rooks
+    rank[indrook = rand(filter(isfree, 1:lrank))] = '♖'
+    if indrook > indking
+        rank[rand(filter(isfree, 1:indking-1))] = '♖'
+    else
+        rank[rand(filter(isfree, indking+1:lrank))] = '♖'
+    end
 
-if rook1 > king
-    rank1[rand(filter(x -> isfree(x) && x < king, 1:8))] = '♖'
-else
-    rank1[rand(filter(x -> isfree(x) && x > king, 1:8))] = '♖'
+    # Place bishops
+    rank[indbish = rand(filter(isfree, 1:8))] = '♗'
+    pbish = filter(iseven(indbish) ? isodd : iseven, 1:lrank)
+    rank[rand(filter(isfree, pbish))] = '♗'
+
+    # Place queen
+    rank[rand(filter(isfree, 1:lrank))] = '♕'
+    return rank
 end
 
-# place bishops
-bishop1 = rand(filter(isfree, 1:8))
-rank1[bishop1] = '♗'
-rank1[rand(filter(x -> isfree(x) && iseven(x) != iseven(bishop1), 1:8))] = '♗'
-
-# place queen
-rank1[rand(filter(isfree, 1:8))] = '♕'
-
-# print first rank
-println(join(rank1))
+@show generateposition()

Task/Generate-Chess960-starting-position/Perl-6/generate-chess960-starting-position-3.pl6

@@ -1,6 +1,4 @@
-constant chess960 = eager
-    .subst(:nth(2), /'♜'/, '♚')
-        if / '♝' [..]* '♝' /
-            for < ♛ ♜ ♜ ♜ ♝ ♝ ♞ ♞ >.permutations».join.uniq;
+constant chess960 =
+   < ♛ ♜ ♜ ♜ ♝ ♝ ♞ ♞ >.permutations».join.unique.grep( / '♝' [..]* '♝' / )».subst(:nth(2), /'♜'/, '♚');
 
 .say for chess960;

Task/Generate-Chess960-starting-position/Perl-6/generate-chess960-starting-position-4.pl6

@@ -1,4 +1,4 @@
-constant chess960 = eager gather for 0..3 -> $q {
+constant chess960 = gather for 0..3 -> $q {
     (my @q = <♜ ♚ ♜>).splice($q, 0, '♛');
     for 0 .. @q -> $n1 {
         (my @n1 = @q).splice($n1, 0, '♞');

Task/Generate-Chess960-starting-position/Rust/generate-chess960-starting-position.rust

@@ -29,9 +29,7 @@ fn main() {
     let mut chess960 = Chess960(BTreeSet::new());
     chess960.invoke("", "KQRRNNBB");
 
-    let mut i = 0;
-    for p in chess960.0 {
+    for (i, p) in chess960.0.iter().enumerate() {
         println!("{}: {}", i, p);
-        i += 1;
     }
 }

Task/Generate-Chess960-starting-position/Scala/generate-chess960-starting-position-1.scala

@@ -0,0 +1,25 @@
+import scala.annotation.tailrec
+
+object Chess960 extends App {
+
+  private val pieces = List('♖', '♗', '♘', '♕', '♔', '♘', '♗', '♖')
+
+  @tailrec
+  private def generateFirstRank(pieces: List[Char]): List[Char] = {
+    def check(rank: String) =
+      rank.matches(".*♖.*♔.*♖.*") && rank.matches(".*♗(..|....|......|)♗.*")
+
+    val p = scala.util.Random.shuffle(pieces)
+    if (check(p.toString.replaceAll("[^\\p{Upper}]", "")))
+      generateFirstRank(pieces)
+    else p
+  }
+
+  loop(10)
+
+  @tailrec
+  private def loop(n: Int): Unit = {
+    println(generateFirstRank(pieces))
+    if (n <= 0) () else loop(n - 1)
+  }
+}