Create rstring.py

rstring.py

@@ -0,0 +1,56 @@
+# Function to create an empty stack. It
+# initializes size of stack as 0
+def createStack():
+	stack = []
+	return stack
+
+# Function to determine the size of the stack
+def size(stack):
+	return len(stack)
+
+# Stack is empty if the size is 0
+def isEmpty(stack):
+	if size(stack) == 0:
+		return true
+
+# Function to add an item to stack . It
+# increases size by 1
+def push(stack, item):
+	stack.append(item)
+
+# Function to remove an item from stack.
+# It decreases size by 1
+def pop(stack):
+	if isEmpty(stack):
+		return
+	return stack.pop()
+
+# A stack based function to reverse a string
+def reverse(string):
+	n = len(string)
+
+	# Create a empty stack
+	stack = createStack()
+
+	# Push all characters of string to stack
+	for i in range(0, n, 1):
+		push(stack, string[i])
+
+	# Making the string empty since all
+	# characters are saved in stack
+	string = ""
+
+	# Pop all characters of string and put
+	# them back to string
+	for i in range(0, n, 1):
+		string += pop(stack)
+
+	return string
+
+
+# Driver code
+s = "string"
+print("The original string is : ", end="")
+print(s)
+print("The reversed string(using stack) is : ", end="")
+print(reverse(s))