added implementing stack using two queues

data_structures/stacks/stack_using_two_queues.py

@@ -0,0 +1,91 @@
+# for explanation refer this  https://www.geeksforgeeks.org/implement-stack-using-queue/
+
+
+class StackWithQueues:
+    def __init__(self):
+        self.queue1 = []
+        self.queue2 = []
+
+    def push(self, element):
+        self.queue1.append(element)
+
+    def pop(self):
+        if not self.queue1:
+            return None
+
+        while len(self.queue1) > 1:
+            self.queue2.append(self.queue1.pop(0))
+
+        element = self.queue1.pop(0)
+
+        self.queue1, self.queue2 = self.queue2, self.queue1
+
+        return element
+
+    def peek(self):
+        if not self.queue1:
+            return None
+
+        while len(self.queue1) > 1:
+            self.queue2.append(self.queue1.pop(0))
+
+        element = self.queue1[0]
+
+        self.queue2.append(self.queue1.pop(0))
+
+        self.queue1, self.queue2 = self.queue2, self.queue1
+
+        return element
+
+    """
+    >>> stack = StackWithQueues()
+    >>> stack.push(1)
+    >>> stack.push(2)
+    >>> stack.push(3)
+    >>> stack.peek()
+    3
+    >>> stack.pop()
+    3
+    >>> stack.peek()
+    2
+    >>> stack.pop()
+    2
+    >>> stack.pop()
+    1
+    >>> stack.peek() is None
+    True
+    """
+
+
+# Initialize the stack
+stack = StackWithQueues()
+
+while True:
+    print("\nChoose operation:")
+    print("1. Push")
+    print("2. Pop")
+    print("3. Peek")
+    print("4. Quit")
+
+    choice = input("Enter choice (1/2/3/4): ")
+
+    if choice == "1":
+        element = input("Enter element to push: ")
+        stack.push(element)
+        print(f"{element} pushed onto the stack.")
+    elif choice == "2":
+        popped_element = stack.pop()
+        if popped_element is not None:
+            print(f"Popped element: {popped_element}")
+        else:
+            print("Stack is empty.")
+    elif choice == "3":
+        peeked_element = stack.peek()
+        if peeked_element is not None:
+            print(f"Top element: {peeked_element}")
+        else:
+            print("Stack is empty.")
+    elif choice == "4":
+        break
+    else:
+        print("Invalid choice. Please try again.")