Update queue-two-stacks-impl.py

Author: ivanmmarkovic

queue/queue-two-stacks-impl.py

@@ -42,6 +42,17 @@ def dequeue(self):
             self.input_stack.push(self.output_stack.pop())
         return ret_value
 
+    def peek(self):
+        if self.is_empty():
+            raise Exception("Queue is empty")
+        while not self.input_stack.is_empty():
+            self.output_stack.push(self.input_stack.pop())
+        ret_value = self.input_stack.pop()
+        self.output_stack.push(ret_value)
+        while not self.output_stack.is_empty():
+            self.input_stack.push(self.output_stack.pop())
+        return ret_value
+
 
 def hot_potato(people: list, num: int) -> str:
     q: Queue = Queue()
@@ -56,4 +67,4 @@ def hot_potato(people: list, num: int) -> str:
     return q.dequeue()
 
 
-print(hot_potato(["Bill", "David", "Susan", "Jane", "Kent", "Brad"], 7))
+print(hot_potato(["Bill", "David", "Susan", "Jane", "Kent", "Brad"], 7))