LeetCode：622. 设计循环队列【模拟循环队列】

题目描述

思路

模拟循环队列即可，具体看代码注释

AC代码

class MyCircularQueue:
    q = [0]
    num = 0 # 当前队列元素个数
    st = 0 # 队头， 队尾st + num - 1
    len = 0 # 队列总大小
    
    # 初始化循环队列大小
    def __init__(self, k: int):
        self.len = k
        self.q = [0] * k # 初始化数组
        
	# 入队
    def enQueue(self, value: int) -> bool:
        if self.isFull(): # 队满
            return False
        self.num += 1 # 队列元素个数+1
        self.q[(self.st + self.num - 1) % self.len] = value # 将元素加入到队尾
        return True
	
	# 出队
    def deQueue(self) -> bool:
        if self.isEmpty(): # 队空
            return False
        self.num -= 1 # 队列元素个数-1
        self.st = (self.st + 1) % self.len # 删除队首元素
        return True

	# 返回队首元素
    def Front(self) -> int:
        if self.isEmpty():
            return -1
        return self.q[self.st]

	# 返回队尾元素
    def Rear(self) -> int:
        if self.isEmpty():
            return -1
        return self.q[(self.st + self.num - 1) % self.len]

	# 判断队列是否为空
    def isEmpty(self) -> bool:
        if self.num == 0:
            return True
        return False

	# 判断是否队满
    def isFull(self) -> bool:
        if self.num == self.len:
            return True
        return False


# Your MyCircularQueue object will be instantiated and called as such:
# obj = MyCircularQueue(k)
# param_1 = obj.enQueue(value)
# param_2 = obj.deQueue()
# param_3 = obj.Front()
# param_4 = obj.Rear()
# param_5 = obj.isEmpty()
# param_6 = obj.isFull()