题目如下
这是输入样例和输出样例
先创建队列的类
class Queue1:
def __init__(self):
self.items = []
def push(self,item):
self.items.append(item)
def pop(self):
return self.items.pop(0)
def isEmpty(self):
return self.items ==[]
def getFront(self):
return self.items[0]
def getSize(self):
return len(self.items)
对输入的数据进行处理
a = Queue1()
for i in range(n):
ls= list(map(int,input().split()))
if ls[0]==1:
a.push(ls[1])
elif ls[0]== 2 :
if a.isEmpty():
print("Invalid")
else:
print(a.pop())
elif ls[0]==3:
print(a.getSize())
else:
for i in range(a.getSize()-1):
print(a.getFront(),end=" ")
a.push(a.getFront())
a.pop()
print(a.getFront())
a.push(a.getFront())
a.pop()



