leetcode-go/medium/622.design-circular-queue.go

type MyCircularQueue struct {
	queue  []int
	size   int
	length int
	beg    int
	end    int
}

/** Initialize your data structure here. Set the size of the queue to be k. */
func Constructor(k int) (queue MyCircularQueue) {
	queue.queue = make([]int, k)
	queue.size = k
	return
}

/** Insert an element into the circular queue. Return true if the operation is successful. */
func (this *MyCircularQueue) EnQueue(value int) bool {
	if this.IsFull() {
		return false
	}
	this.queue[this.end] = value
	this.end = (this.end + 1) % this.size
	this.length++
	return true
}

/** Delete an element from the circular queue. Return true if the operation is successful. */
func (this *MyCircularQueue) DeQueue() bool {
	if this.IsEmpty() {
		return false
	}
	this.beg = (this.beg + 1) % this.size
	this.length--
	return true
}

/** Get the front item from the queue. */
func (this *MyCircularQueue) Front() int {
	if this.IsEmpty() {
		return -1
	}
	return this.queue[this.beg]
}

/** Get the last item from the queue. */
func (this *MyCircularQueue) Rear() int {
	if this.IsEmpty() {
		return -1
	}
	return this.queue[(this.end+this.size-1)%this.size]
}

/** Checks whether the circular queue is empty or not. */
func (this *MyCircularQueue) IsEmpty() bool {
	return this.length == 0
}

/** Checks whether the circular queue is full or not. */
func (this *MyCircularQueue) IsFull() bool {
	return this.length == this.size
}

/**
 * Your MyCircularQueue object will be instantiated and called as such:
 * obj := Constructor(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();
 */