chengchengxu15 / CS-leaning

1 stars 1 forks source link

622. Design Circular Queue #27

Closed chengchengxu15 closed 3 years ago

chengchengxu15 commented 3 years ago

https://leetcode.com/problems/design-circular-queue/

solution: https://leetcode-cn.com/problems/design-circular-queue/solution/she-ji-xun-huan-dui-lie-by-leetcode/#comment

chengchengxu15 commented 3 years ago
class MyCircularQueue:

    def __init__(self, k: int):
        """
        Initialize your data structure here. Set the size of the queue to be k.
        """
        self.queue = [0]*k
        self.headIndex = 0
        self.count = 0
        self.capacity = k

    def enQueue(self, value: int) -> bool:
        """
        Insert an element into the circular queue. Return true if the operation is successful.
        """
        if self.count == self.capacity:
            return False
        self.queue[(self.headIndex + self.count) % self.capacity] = value
        self.count += 1
        return True

    def deQueue(self) -> bool:
        """
        Delete an element from the circular queue. Return true if the operation is successful.
        """
        if self.count == 0:
            return False
        self.headIndex = (self.headIndex + 1) % self.capacity
        self.count -= 1
        return True

    def Front(self) -> int:
        """
        Get the front item from the queue.
        """
        if self.count == 0:
            return -1
        return self.queue[self.headIndex]

    def Rear(self) -> int:
        """
        Get the last item from the queue.
        """
        # empty queue
        if self.count == 0:
            return -1
        return self.queue[(self.headIndex + self.count - 1) % self.capacity]

    def isEmpty(self) -> bool:
        """
        Checks whether the circular queue is empty or not.
        """
        return self.count == 0

    def isFull(self) -> bool:
        """
        Checks whether the circular queue is full or not.
        """
        return self.count == self.capacity

# 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()