Merge pull request #8 from 246859/feat-linked_stack

Feat linked stack

TODO.md

@@ -33,7 +33,7 @@
 
 - stack
   - ArrayStack ✔️
-  - LinkedStack
+  - LinkedStack ✔️
 
 - heap
   - BinaryHeap ✔️

lists/linked_list.go

@@ -357,7 +357,7 @@ func (l *LinkedList[T]) String() string {
 	var b strings.Builder
 	b.WriteString("LinkedList[")
 	elems := l.Values()
-	for i, v := range l.Values() {
+	for i, v := range elems {
 		b.WriteString(fmt.Sprintf("%v", v))
 		if i != len(elems)-1 {
 			b.WriteByte(',')

stacks/linked_stack.go

@@ -0,0 +1,68 @@
+package stacks
+
+import (
+	"fmt"
+	"github.com/246859/containers"
+	"github.com/246859/containers/lists"
+	"strings"
+)
+
+var _ Stack[any] = (*LinkedStack[any])(nil)
+
+func NewLinkedStack[T any]() *LinkedStack[T] {
+	return &LinkedStack[T]{
+		list: lists.NewLinkedList[T](),
+	}
+}
+
+// LinkedStack is the stack implemented by lists.LinkedList
+type LinkedStack[T any] struct {
+	list *lists.LinkedList[T]
+}
+
+func (l *LinkedStack[T]) Push(t ...T) {
+	l.list.Add(t...)
+}
+
+func (l *LinkedStack[T]) Pop() (T, bool) {
+	val, found := l.list.Get(l.Size() - 1)
+	if !found {
+		return val, false
+	}
+	l.list.Remove(l.Size() - 1)
+	return val, true
+}
+
+func (l *LinkedStack[T]) Peek() (T, bool) {
+	return l.list.Get(l.Size() - 1)
+}
+
+func (l *LinkedStack[T]) Values() []T {
+	return l.list.Values()
+}
+
+func (l *LinkedStack[T]) Size() int {
+	return l.list.Size()
+}
+
+func (l *LinkedStack[T]) Clear() {
+	l.list.Clear()
+}
+
+func (l *LinkedStack[T]) Iterator() containers.IndexIterator[T] {
+	return l.list.Iterator()
+}
+
+func (l *LinkedStack[T]) String() string {
+	var b strings.Builder
+	b.WriteString("LinkedStack[")
+	elems := l.Values()
+	for i, v := range elems {
+		b.WriteString(fmt.Sprintf("%v", v))
+		if i != len(elems)-1 {
+			b.WriteByte(',')
+		}
+	}
+	b.WriteByte(']')
+	return b.String()
+}

stacks/linked_stack_test.go

@@ -0,0 +1,83 @@
+package stacks
+
+import (
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+func TestLinkedStack_Push_Pop(t *testing.T) {
+	data := []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
+
+	stack := NewLinkedStack[int]()
+	stack.Push(data[:5]...)
+	stack.Push(data[5:]...)
+
+	for i := len(data) - 1; i >= 0; i-- {
+		d := data[i]
+		pop, b := stack.Pop()
+		assert.True(t, b)
+		assert.Equal(t, d, pop)
+	}
+}
+
+func TestLinkedStack_Push_Peek(t *testing.T) {
+	data := []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
+
+	stack := NewLinkedStack[int]()
+	stack.Push(data[:5]...)
+	stack.Push(data[5:]...)
+
+	for i := len(data) - 1; i >= 0; i-- {
+		d := data[i]
+		pop, b := stack.Peek()
+		assert.True(t, b)
+		assert.Equal(t, d, pop)
+
+		stack.Pop()
+	}
+
+}
+
+func TestLinkedStack_Iterator(t *testing.T) {
+	data := []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
+
+	stack := NewLinkedStack[int]()
+	stack.Push(data[:5]...)
+	stack.Push(data[5:]...)
+
+	it := stack.Iterator()
+	for ; it.Valid(); it.Next() {
+		assert.Equal(t, data[it.Index()], it.Value())
+	}
+
+	it.Reverse()
+	it.Rewind()
+
+	for ; it.Valid(); it.Next() {
+		assert.Equal(t, data[it.Index()], it.Value())
+	}
+}
+
+func TestLinkedStack_Values(t *testing.T) {
+	data := []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
+
+	stack := NewLinkedStack[int]()
+	stack.Push(data[:5]...)
+	stack.Push(data[5:]...)
+
+	values := stack.Values()
+
+	for i := 0; i < len(values); i++ {
+		assert.Equal(t, data[i], values[i])
+	}
+}
+
+func TestLinkedStack_Size(t *testing.T) {
+	data := []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
+
+	stack := NewLinkedStack[int]()
+	stack.Push(data[:5]...)
+	assert.Equal(t, 5, stack.Size())
+	stack.Push(data[5:]...)
+	assert.Equal(t, 10, stack.Size())
+}

stacks/stack.go

@@ -8,4 +8,6 @@ type Stack[T any] interface {
 	Peek() (T, bool)
 
 	containers.Container[T]
+
+	containers.IndexIterable[T]
 }