栈和队列

 1 #栈（stack）
 2 class Stack:
 3     def __init__(self,S=[]):
 4         #初始化空栈，设置属性栈顶指针top和栈的列表表示
 5         self.top=len(S)-1
 6         self.list=S
 7     def stack_empty(self):
 8         #判断栈空
 9         if self.top==-1:
10             return True
11         else:
12             return False
13     def push(self,x):
14         #栈的压入操作
15         self.top+=1#栈顶指针+1
16         self.list.append(x)#把x添加进栈
17     def pop(self):
18         #栈的弹出操作
19         if self.stack_empty():
20             print("underflow")
21         else:
22             self.top-=1
23             return self.list.pop()
24     def top_element(self):
25         #返回栈顶元素
26         return self.list[S.top]
27 
28 A=[15,6,2,9,17,3]
29 S=Stack(A)
30 print(S)
31 print(S.top)
32 print(S.list)
33 print(S.stack_empty())
34 print(S.top_element())
35 print(‘#‘*60)
36 S.pop()
37 S.push(100)
38 print(S.list)
39 print(S.top_element())
40 ------------------------------------------------------
41 <__main__.Stack object at 0x0102B4D0>
42 5
43 [15, 6, 2, 9, 17, 3]
44 False
45 3
46 ############################################################
47 [15, 6, 2, 9, 17, 100]
48 False
49 100

 1 #队列
 2 class Queue:
 3     def __init__(self,Q,head,tail,size):
 4         #初始化一个队列，给出头指针，给定总的队的大小size
 5         self.list=Q
 6         self.head=head
 7         self.tail=tail
 8         self.size=size
 9 
10     def enqueue(self,x):
11         #入队操作，判断上溢，改变队尾指针
12         if self.head==self.tail+1 or (self.head==0 and self.tail == self.size-1):
13             return "overflow"
14         self.list.append(x)
15         if self.tail == self.size-1:
16             self.tail=0
17         else:
18             self.tail+=1
19 
20     def dequeue(self):
21         #出队操作，判断下溢，改变队头指针
22         if self.head==self.tail:
23             return "underflow"
24         x=self.list[0]
25         self.list.remove(self.list[0])
26         if self.head==self.size-1:
27             self.head=0
28         else:
29             self.head+=1
30         return x
31 
32 A=[15,6,9,8,4]
33 Q = Queue(A,6,10,11)
34 print(Q)
35 print(Q.list)
36 print(Q.head)
37 print(Q.tail)
38 print(Q.size)
39 print(‘#‘*60)
40 Q.enqueue(17)
41 Q.enqueue(3)
42 Q.enqueue(5)
43 print(Q.list)
44 print(Q.head)
45 print(Q.tail)
46 print(‘#‘*60)
47 a=Q.dequeue()
48 print(a)
49 print(Q.list)
50 print(Q.head)
51 print(Q.tail)
52 print(‘#‘*60)
53 b=Q.dequeue()
54 print(b)
55 print(Q.list)
56 print(Q.head)
57 print(Q.tail)
58 ----------------------------------------------------------------
59 [15, 6, 9, 8, 4]
60 6
61 10
62 11
63 ############################################################
64 [15, 6, 9, 8, 4, 17, 3, 5]
65 6
66 2
67 ############################################################
68 15
69 [6, 9, 8, 4, 17, 3, 5]
70 7
71 2
72 ############################################################
73 6
74 [9, 8, 4, 17, 3, 5]
75 8
76 2