Initial data commit

Task/Evaluate-binomial-coefficients/Python/evaluate-binomial-coefficients-2.py

@@ -0,0 +1,23 @@
+from operator import mul
+from functools import reduce
+
+
+def comb(n,r):
+    ''' calculate nCr - the binomial coefficient
+    >>> comb(3,2)
+    3
+    >>> comb(9,4)
+    126
+    >>> comb(9,6)
+    84
+    >>> comb(20,14)
+    38760
+    '''
+
+    if r > n-r:
+        # r = n-r   for smaller intermediate values during computation
+        return ( reduce( mul, range((n - (n-r) + 1), n + 1), 1)
+                 // reduce( mul, range(1, (n-r) + 1), 1) )
+    else:
+        return ( reduce( mul, range((n - r + 1), n + 1), 1)
+                 // reduce( mul, range(1, r + 1), 1) )