leetcode-go/medium/641.design-circular-deque.go

type MyCircularDeque struct {
	deque  []int
	size   int
	length int
	beg    int
	end    int
}

/** Initialize your data structure here. Set the size of the deque to be k. */
func Constructor(k int) (deque MyCircularDeque) {
	deque.deque = make([]int, k)
	deque.size, deque.beg = k, 1
	return
}

/** Adds an item at the front of Deque. Return true if the operation is successful. */
func (this *MyCircularDeque) InsertFront(value int) bool {
	if this.IsFull() {
		return false
	}
	this.beg = (this.beg + this.size - 1) % this.size
	this.deque[this.beg] = value
	this.length++
	return true
}

/** Adds an item at the rear of Deque. Return true if the operation is successful. */
func (this *MyCircularDeque) InsertLast(value int) bool {
	if this.IsFull() {
		return false
	}
	this.end = (this.end + 1) % this.size
	this.deque[this.end] = value
	this.length++
	return true
}

/** Deletes an item from the front of Deque. Return true if the operation is successful. */
func (this *MyCircularDeque) DeleteFront() bool {
	if this.IsEmpty() {
		return false
	}
	this.beg = (this.beg + 1) % this.size
	this.length--
	return true
}

/** Deletes an item from the rear of Deque. Return true if the operation is successful. */
func (this *MyCircularDeque) DeleteLast() bool {
	if this.IsEmpty() {
		return false
	}
	this.end = (this.end + this.size - 1) % this.size
	this.length--
	return true
}

/** Get the front item from the deque. */
func (this *MyCircularDeque) GetFront() int {
	if this.IsEmpty() {
		return -1
	}
	return this.deque[this.beg]
}

/** Get the last item from the deque. */
func (this *MyCircularDeque) GetRear() int {
	if this.IsEmpty() {
		return -1
	}
	return this.deque[this.end]
}

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

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

/**
 * Your MyCircularDeque object will be instantiated and called as such:
 * obj := Constructor(k);
 * param_1 := obj.InsertFront(value);
 * param_2 := obj.InsertLast(value);
 * param_3 := obj.DeleteFront();
 * param_4 := obj.DeleteLast();
 * param_5 := obj.GetFront();
 * param_6 := obj.GetRear();
 * param_7 := obj.IsEmpty();
 * param_8 := obj.IsFull();
 */