Create stack_two_queues.py

Author: ivanmmarkovic

stack_two_queues.py

@@ -0,0 +1,67 @@
+from typing import Any, List
+
+
+class Queue:
+
+    def __init__(self) -> None:
+        self.queue:List[Any] = []
+
+    def size(self) -> int:
+        return len(self.queue)
+
+    def is_empty(self) -> bool:
+        return len(self.queue) == 0
+
+    def enqueue(self, item:Any) -> None:
+        self.queue.insert(0, item)
+
+    def dequeue(self) -> Any:
+        if self.is_empty():
+            raise Exception('Queue is empty')
+        return self.queue.pop()
+
+
+
+class Stack:
+
+    def __init__(self):
+        self.input: Queue = Queue()
+        self.output:Queue = Queue()
+        
+
+    def push(self, x: Any) -> None:
+        self.input.enqueue(x)
+        
+
+    def pop(self) -> Any:
+        if self.input.is_empty():
+            raise Exception('Queue is empty')
+        
+        while self.input.size() > 1:
+            self.output.enqueue(self.input.dequeue())
+            
+        item:Any = self.input.dequeue()
+
+        while not self.output.is_empty():
+            self.input.enqueue(self.output.dequeue())
+            
+        return item
+
+
+    def peek(self) -> Any:
+        if self.input.is_empty():
+            raise Exception('Queue is empty')
+            
+        while self.input.size() > 1:
+            self.output.enqueue(self.input.dequeue())
+            
+        item:Any = self.input.dequeue()
+        self.output.enqueue(item)
+        
+        while not self.output.is_empty():
+            self.input.enqueue(self.output.dequeue())
+        return item
+        
+
+    def is_empty(self) -> bool:
+        return self.input.is_empty()