Update rod_cutting.py

added doctests

dynamic_programming/rod_cutting.py

@@ -1,27 +1,19 @@
-### SOLUTION ###
-"""
-Optimal Substructure: 
-When we receive a rod, we have two options:
-a) Don't cut it and sell it as is (receiving prices[length])
-b) Cut it and sell it in two parts. The length we cut it and the rod we are
-left with, which we have to try and sell separately in an efficient way.
-Choose the maximum price we can get.
-"""
 
 def rod_cutting_recursive(prices,length):
 	"""
 	Given a rod of length n and array of prices that indicate price at each length.
 	Determine the maximum value obtainable by cutting up the rod and selling the pieces
-
+	>>> rod_cutting_recursive([0,1,5,8,9],4) 
+	10
+	>>> rod_cutting_recursive([0,1,1,1],3) 
+	3
+
 	Args:
-		prices: list indicating price at each length, where prices[0] = 0 indicating rod of zero length has no value
+	    prices: list indicating price at each length, where prices[0] = 0 indicating rod of zero length has no value
 	    length: length of rod
-
+	    
 	Returns:
 	    Maximum revenue attainable by cutting up the rod in any way. 
-
-	Raises:
-	    KeyError: Raises an exception.
 	"""
 	#base case 
 	if length == 0:
@@ -34,7 +26,7 @@ def rod_cutting_recursive(prices,length):
 
 def main():
 	assert rod_cutting_recursive([0,1,5,8,9,10,17,17,20,24,30],10) == 30
-    
+
 if __name__ == '__main__':
 	main()