go: add «641. Design Circular Deque»

Signed-off-by: Matej Focko <me@mfocko.xyz>

go/design-circular-deque.go

@@ -0,0 +1,86 @@
+package main
+
+type MyCircularDeque struct {
+	maxSize int
+
+	deque []int
+	size  int
+	i     int
+}
+
+func Constructor(k int) MyCircularDeque {
+	return MyCircularDeque{
+		maxSize: k,
+		deque:   make([]int, k),
+		size:    0,
+		i:       0,
+	}
+}
+
+func (this *MyCircularDeque) InsertFront(value int) bool {
+	if this.IsFull() {
+		return false
+	}
+
+	this.i = (this.i - 1 + this.maxSize) % this.maxSize
+	this.deque[this.i] = value
+	this.size++
+
+	return true
+}
+
+func (this *MyCircularDeque) InsertLast(value int) bool {
+	if this.IsFull() {
+		return false
+	}
+
+	this.deque[(this.i+this.size)%this.maxSize] = value
+	this.size++
+
+	return true
+}
+
+func (this *MyCircularDeque) DeleteFront() bool {
+	if this.IsEmpty() {
+		return false
+	}
+
+	this.size--
+	this.i = (this.i + 1) % this.maxSize
+
+	return true
+}
+
+func (this *MyCircularDeque) DeleteLast() bool {
+	if this.IsEmpty() {
+		return false
+	}
+
+	this.size--
+
+	return true
+}
+
+func (this *MyCircularDeque) GetFront() int {
+	if this.IsEmpty() {
+		return -1
+	}
+
+	return this.deque[this.i]
+}
+
+func (this *MyCircularDeque) GetRear() int {
+	if this.IsEmpty() {
+		return -1
+	}
+
+	return this.deque[(this.i+this.size-1)%this.maxSize]
+}
+
+func (this *MyCircularDeque) IsEmpty() bool {
+	return this.size == 0
+}
+
+func (this *MyCircularDeque) IsFull() bool {
+	return this.size == this.maxSize
+}