Create distinct_subsequences_recursive.py

Author: careermonk

dynamic-programming/distinct_subsequences_recursive.py

@@ -0,0 +1,30 @@
+# Copyright (c) June 02, 2017 CareerMonk Publications and others.
+# E-Mail           		: [email protected]
+# Creation Date    		: 2017-06-02 06:15:46
+# Last modification		: 2017-06-02
+# Modified by		        : Narasimha Karumanchi
+# Book Title			: Algorithm Design Techniques
+# Warranty         		: This software is provided "as is" without any
+# 				 warranty; without even the implied warranty of
+# 				 merchantability or fitness for a particular purpose.
+
+def distinct_subsequences(S, T):
+	m = len(S)
+	n = len(T)
+	# Base conditions
+	if (m==0):
+		return 0
+	if (n==0):
+		return 1
+	if (m==1 and n==1):
+	    if (S[0]==T[0]):
+		    return 1
+	    else:
+		    return 0
+
+	if (S[m-1]==T[n-1]):
+		return distinct_subsequences(S[:-1], T[:-1]) + distinct_subsequences(S[:-1], T)
+	else:
+		return distinct_subsequences(S[:-1], T)
+ 
+print distinct_subsequences("abadcb", "ab")