Golang program for implementation LIFO Stack and FIFO Queue

A stack is an ordered list in which all insertions and deletions are made at one end, called the top. A queue is an ordered list in which all insertions take place at one end, the rear, while all deletions take place at the other end, the front.Stacks are sometimes referred to as Last In First Out (LIFO) lists and queues are known as First In First Out (FIFO) lists.


package main
import (
type Node struct {
    Value int
func (n *Node) String() string {
    return fmt.Sprint(n.Value)
// NewStack returns a new stack.
func NewStack() *Stack {
    return &Stack{}
// Stack is a basic LIFO stack that resizes as needed.
type Stack struct {
    nodes []*Node
    count int
// Push adds a node to the stack.
func (s *Stack) Push(n *Node) {
    s.nodes = append(s.nodes[:s.count], n)
// Pop removes and returns a node from the stack in last to first order.
func (s *Stack) Pop() *Node {
    if s.count == 0 {
        return nil
    return s.nodes[s.count]
// NewQueue returns a new queue with the given initial size.
func NewQueue(size int) *Queue {
    return &Queue{
        nodes: make([]*Node, size),
        size:  size,
// Queue is a basic FIFO queue based on a circular list that resizes as needed.
type Queue struct {
    nodes []*Node
    size  int
    head  int
    tail  int
    count int
// Push adds a node to the queue.
func (q *Queue) Push(n *Node) {
    if q.head == q.tail && q.count > 0 {
        nodes := make([]*Node, len(q.nodes)+q.size)
        copy(nodes, q.nodes[q.head:])
        copy(nodes[len(q.nodes)-q.head:], q.nodes[:q.head])
        q.head = 0
        q.tail = len(q.nodes)
        q.nodes = nodes
    q.nodes[q.tail] = n
    q.tail = (q.tail + 1) % len(q.nodes)
// Pop removes and returns a node from the queue in first to last order.
func (q *Queue) Pop() *Node {
    if q.count == 0 {
        return nil
    node := q.nodes[q.head]
    q.head = (q.head + 1) % len(q.nodes)
    return node
func main() {
    s := NewStack()
    fmt.Println(s.Pop(), s.Pop(), s.Pop(), s.Pop())
    q := NewQueue(1)
    fmt.Println(q.Pop(), q.Pop(), q.Pop(), q.Pop())


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