converted dir tree

server/internal/stack.go

@@ -0,0 +1,37 @@
+package internal
+
+type Node[T any] struct {
+	Value T
+}
+
+type Stack[T any] struct {
+	Nodes []*Node[T]
+	count int
+}
+
+func (s *Stack[T]) Push(n *Node[T]) {
+	if s.count >= len(s.Nodes) {
+		Nodes := make([]*Node[T], len(s.Nodes)*2)
+		copy(Nodes, s.Nodes)
+		s.Nodes = Nodes
+	}
+	s.Nodes[s.count] = n
+	s.count++
+}
+
+func (s *Stack[T]) Pop() *Node[T] {
+	if s.count == 0 {
+		return nil
+	}
+	node := s.Nodes[s.count-1]
+	s.count--
+	return node
+}
+
+func (s *Stack[T]) IsEmpty() bool {
+	return s.count == 0
+}
+
+func (s *Stack[T]) IsNotEmpty() bool {
+	return s.count != 0
+}