Data commit

Task/Generate-Chess960-starting-position/Python/generate-chess960-starting-position-1.py

@@ -0,0 +1,11 @@
+>>> from itertools import permutations
+>>> pieces = 'KQRrBbNN'
+>>> starts = {''.join(p).upper() for p in permutations(pieces)
+                     if p.index('B') % 2 != p.index('b') % 2 		# Bishop constraint
+                     and ( p.index('r') < p.index('K') < p.index('R')	# King constraint	
+                           or p.index('R') < p.index('K') < p.index('r') ) }
+>>> len(starts)
+960
+>>> starts.pop()
+'QNBRNKRB'
+>>>

Task/Generate-Chess960-starting-position/Python/generate-chess960-starting-position-2.py

@@ -0,0 +1,11 @@
+>>> import re
+>>> pieces = 'KQRRBBNN'
+>>> bish = re.compile(r'B(|..|....|......)B').search
+>>> king = re.compile(r'R.*K.*R').search
+>>> starts3 = {p for p in (''.join(q) for q in permutations(pieces))
+            if bish(p) and king(p)}
+>>> len(starts3)
+960
+>>> starts3.pop()
+'QRNKBNRB'
+>>>

Task/Generate-Chess960-starting-position/Python/generate-chess960-starting-position-3.py

@@ -0,0 +1,15 @@
+from random import choice
+
+def random960():
+    start = ['R', 'K', 'R']         # Subsequent order unchanged by insertions.
+    #
+    for piece in ['Q', 'N', 'N']:
+        start.insert(choice(range(len(start)+1)), piece)
+    #
+    bishpos = choice(range(len(start)+1))
+    start.insert(bishpos, 'B')
+    start.insert(choice(range(bishpos + 1, len(start) + 1, 2)), 'B')
+    return start
+    return ''.join(start).upper()
+
+print(random960())

Task/Generate-Chess960-starting-position/Python/generate-chess960-starting-position-4.py

@@ -0,0 +1,31 @@
+from random import choice
+
+def generate960():
+    start = ('R', 'K', 'R')         # Subsequent order unchanged by insertions.
+
+    # Insert QNN in all combinations of places
+    starts = {start}
+    for piece in ['Q', 'N', 'N']:
+        starts2 = set()
+        for s in starts:
+            for pos in range(len(s)+1):
+                s2 = list(s)
+                s2.insert(pos, piece)
+                starts2.add(tuple(s2))
+        starts = starts2
+
+    # For each of the previous starting positions insert the bishops in their 16 positions
+    starts2 = set()
+    for s in starts:
+        for bishpos in range(len(s)+1):
+            s2 = list(s)
+            s2.insert(bishpos, 'B')
+            for bishpos2 in range(bishpos+1, len(s)+2, 2):
+                s3 = s2[::]
+                s3.insert(bishpos2, 'B')
+                starts2.add(tuple(s3))
+
+    return  list(starts2)
+
+gen = generate960()
+print(''.join(choice(gen)))