Add recursion, ankitdobhal/Python-Scripts#1

Scripts/recursion.py

@@ -0,0 +1,35 @@
+# "Towers of Hanoi" Game
+# A recursive solution almost forces itself on the programmer,
+# while the iterative solution of the game is hard to find and to grasp.
+# 
+# "Recursion"
+# Recursion is a method of programming or coding a problem,
+# in which a function calls itself one or more times in its body.
+# Usually, it is returning the return value of this function call.
+# If a function definition satisfies the condition of recursion, we call this function a recursive function. 
+
+
+def hanoi(n, source, helper, target):
+    if n > 0:
+        # move tower of size n-1 to helper:
+        hanoi(n-1, source, target, helper)
+        # move disk from source to target:
+        if source:
+            target.append(source.pop())
+        # move tower of size n-1 from helper to target:
+        hanoi(n-1, helper, source, target)
+
+if __name__ == "__main__":
+    height = int(input("Enter the height of the tower: "))
+    source = [disk for disk in range(1, height+1)]
+    helper = []
+    target = []
+    print("Before calling the recursive function...")
+    print("Source tower: ", str(source))
+    print("Target tower: ", str(target))
+
+    # call the hanoi function to start recursie execution
+    hanoi(height, source, helper, target)
+    print("After recursive calls...")
+    print("Source tower: ", str(source))
+    print("Target tower: ", str(target))