-

cool-RR · cool-RR · commit 6d252eccf6f0 · 2014-09-26T19:34:19.000+03:00
diff --git a/source_py3/python_toolbox/math_tools/sequences.py b/source_py3/python_toolbox/math_tools/sequences.py
@@ -2,6 +2,7 @@
 # This program is distributed under the MIT license.
 
 import numbers
+import collections
 
 
 infinity = float('inf')
@@ -11,7 +12,7 @@
 _n_highest_cache_completed = -1
 def stirling(n, k, skip_calculation=False):
     '''
-    blocktododoc specify first or second kind
+    blocktododoc specify first kind
     '''
     global _n_highest_cache_completed
     if k not in range(n + 1):
@@ -55,3 +56,22 @@ def stirling(n, k, skip_calculation=False):
 def abs_stirling(n, k):
     return abs(stirling(n, k))
     
+###############################################################################
+
+_shitfuck_cache = {}
+
+def shitfuck(k, recurrences):
+    from python_toolbox import nifty_collections
+    assert isinstance(recurrences, nifty_collections.FrozenCounter)
+    levels = [collections.Counter({recurrences: 1})]
+    while len(levels) < k and any(((k - len(levels) + 1), recurrences)
+                                   not in _shitfuck_cache for x in levels[-1]):
+        new_level = collections.Counter()
+        for recurrences_, factor in levels[-1].items():
+            for smaller_recurrences in recurrences_.counters_with_one_removed:
+                new_level[(k - len(levels), smaller_recurrences)] += factor
+        levels.append(new_level)
+    # The last level is calculated. Time to make our way up.
+    if len(levels) == k:
+        
+            
diff --git a/source_py3/python_toolbox/nifty_collections/frozen_counter.py b/source_py3/python_toolbox/nifty_collections/frozen_counter.py
@@ -6,6 +6,9 @@
 import itertools
 import collections
 
+from python_toolbox import caching
+
+from .lazy_tuple import LazyTuple
 from .frozen_dict import FrozenDict
 
 try:                                    # Load C helper function if available
@@ -201,3 +204,14 @@ def __and__(self, other):
             if new_count > 0:
                 result[element] = new_count
         return FrozenCounter(result)
+
+    @caching.CachedProperty
+    @LazyTuple.factory()
+    def counters_with_one_removed(self):
+        for key_to_reduce in self.keys():
+            return type(self)(
+                {key: (value - (key == key_to_reduce)) for key, value
+                                                               in self.items()}
+            )
+        
+        
