queue

Author: AstinCHOI

7장_추상_데이터_구조/1_stack.py

@@ -31,7 +31,7 @@ def __repr__(self):
 if __name__ == '__main__':
     stack = Stack()
     print(f"스택이 비었나요? {stack.isEmpty()}")
-    print("스택에 0-9까지의 항목을 추가합니다.")
+    print("스택에 숫자 0~9를 추가합니다.")
     for i in range(10):
         stack.push(i)
     print(f"스택 크기: {stack.size()}")

7장_추상_데이터_구조/2_stack_with_node.py

@@ -20,34 +20,34 @@ def pop(self):
             self.head = node.pointer
             return node.value
         else:
-            print('Stack is empty.')
+            print("Stack is empty.")
 
     def peek(self):
         if self.head:
             return self.head.value
         else:
-            print('Stack is empty.')
+            print("Stack is empty.")
 
     def size(self):
         node = self.head
         count = 0
         while node:
-            count +=1
+            count += 1
             node = node.pointer
         return count
 
     def _printList(self):
         node = self.head
         while node:
-            print(node.value, end=' ')
+            print(node.value, end=" ")
             node = node.pointer
         print()
 
 
 if __name__ == '__main__':
     stack = Stack()
     print(f"스택이 비었나요? {stack.isEmpty()}")
-    print("스택에 0-9까지의 항목을 추가합니다.")
+    print("스택에 숫자 0~9를 추가합니다.")
     for i in range(10):
         stack.push(i)
     stack._printList()

7장_추상_데이터_구조/3_queue.py

@@ -23,13 +23,13 @@ def __repr__(self):
 
 if __name__ == '__main__':
     queue = Queue()
-    print("Is the queue empty? ", queue.isEmpty())
-    print("Adding 0 to 10 in the queue...")
+    print(f"큐가 비었나요? {queue.isEmpty()}")
+    print("큐에 숫자 0~9를 추가합니다.")
     for i in range(10):
         queue.enqueue(i)
-    print("Queue size: ", queue.size())
-    print("Queue peek : ", queue.peek())
-    print("Dequeue...", queue.dequeue())
-    print("Queue peek: ", queue.peek())
-    print("Is the queue empty? ", queue.isEmpty())
+    print(f"큐 크기: {queue.size()}")
+    print(f"peek: {queue.peek()}")
+    print(f"dequeue: {queue.dequeue()}")
+    print(f"peek: {queue.peek()}")
+    print(f"큐가 비었나요? {queue.isEmpty()}")
     print(queue)

7장_추상_데이터_구조/4_queue_from_two_stacks.py

@@ -0,0 +1,55 @@
+class Queue(object):
+    def __init__(self):
+        self.in_stack = []
+        self.out_stack = []
+
+    def _transfer(self):
+        while self.in_stack:
+            self.out_stack.append(self.in_stack.pop())
+
+    def enqueue(self, item):
+        return self.in_stack.append(item)
+
+    def dequeue(self):
+        if not self.out_stack:
+            self._transfer()
+        if self.out_stack:
+            return self.out_stack.pop()
+        else:
+            return "Queue empty!"
+
+    def size(self):
+        return len(self.in_stack) + len(self.out_stack)
+
+    def peek(self):
+        if not self.out_stack:
+            self._transfer()
+        if self.out_stack:
+            return self.out_stack[-1]
+        else:
+            return "Queue empty!"
+
+    def __repr__(self):
+        if not self.out_stack:
+            self._transfer()
+        if self.out_stack:
+            return f"{self.out_stack}"
+        else:
+            return "Queue empty!"
+
+    def isEmpty(self):
+        return not (bool(self.in_stack) or bool(self.out_stack))
+
+
+if __name__ == '__main__':
+    queue = Queue()
+    print(f"큐가 비었나요? {queue.isEmpty()}")
+    print("큐에 숫자 0~9를 추가합니다.")
+    for i in range(10):
+        queue.enqueue(i)
+    print(f"큐 크기: {queue.size()}")
+    print(f"peek: {queue.peek()}")
+    print(f"dequeue: {queue.dequeue()}")
+    print(f"peek: {queue.peek()}")
+    print(f"큐가 비었나요? {queue.isEmpty()}")
+    print(queue)

7장_추상_데이터_구조/5_linked_queue.py

@@ -0,0 +1,65 @@
+class Node(object):
+    def __init__(self, value=None, pointer=None):
+        self.value = value
+        self.pointer = None
+
+
+class LinkedQueue(object):
+    def __init__(self):
+        self.head = None
+        self.tail = None
+
+    def isEmpty(self):
+        return not bool(self.head)
+
+    def dequeue(self):
+        if self.head:
+            value = self.head.value
+            self.head = self.head.pointer
+            return value
+        else:
+            print("Queue is empty, cannot dequeue.")
+
+    def enqueue(self, value):
+        node = Node(value)
+        if not self.head:
+            self.head = node
+            self.tail = node
+        else:
+            if self.tail:
+                self.tail.pointer = node
+            self.tail = node
+
+    def size(self):
+        node = self.head
+        num_nodes = 0
+        while node:
+                num_nodes += 1
+                node = node.pointer
+        return num_nodes
+
+    def peek(self):
+        return self.head.value
+
+    def _print(self):
+        node = self.head
+        while node:
+            print(node.value, end=" ")
+            node = node.pointer
+        print()
+
+
+if __name__ == '__main__':
+    queue = LinkedQueue()
+    print(f"큐가 비었나요? {queue.isEmpty()}")
+    print("큐에 숫자 0~9를 추가합니다.")
+    for i in range(10):
+        queue.enqueue(i)
+    print(f"큐가 비었나요? {queue.isEmpty()}")
+    queue._print()
+
+    print(f"큐 크기: {queue.size()}")
+    print(f"peek: {queue.peek()}")
+    print(f"dequeue: {queue.dequeue()}")
+    print(f"peek: {queue.peek()}")
+    queue._print()