feat: add DoublyLink data structure

datastructure/doublylink_test.go

@@ -0,0 +1,165 @@
+package datastructure
+
+import (
+	"testing"
+
+	"github.com/duke-git/lancet/internal"
+)
+
+func TestDoublyLink_InsertAtFirst(t *testing.T) {
+	assert := internal.NewAssert(t, "TestDoublyLink_InsertAtFirst")
+
+	link := NewDoublyLink[int]()
+	link.InsertAtHead(1)
+	link.InsertAtHead(2)
+	link.InsertAtHead(3)
+	link.Print()
+
+	expected := []int{3, 2, 1}
+	values := link.Values()
+
+	assert.Equal(expected, values)
+}
+
+func TestDoublyLink_InsertAtTail(t *testing.T) {
+	assert := internal.NewAssert(t, "TestDoublyLink_InsertAtTail")
+
+	link := NewDoublyLink[int]()
+	link.InsertAtTail(1)
+	link.InsertAtTail(2)
+	link.InsertAtTail(3)
+	link.Print()
+
+	expected := []int{1, 2, 3}
+	values := link.Values()
+
+	assert.Equal(expected, values)
+}
+
+func TestDoublyLink_InsertAt(t *testing.T) {
+	assert := internal.NewAssert(t, "TestDoublyLink_InsertAt")
+
+	link := NewDoublyLink[int]()
+
+	err := link.InsertAt(1, 1)
+	assert.IsNotNil(err)
+
+	err = link.InsertAt(0, 1)
+	err = link.InsertAt(1, 2)
+	err = link.InsertAt(2, 4)
+	err = link.InsertAt(2, 3)
+
+	if err != nil {
+		t.FailNow()
+	}
+	link.Print()
+
+	expected := []int{1, 2, 3, 4}
+	values := link.Values()
+
+	assert.Equal(expected, values)
+
+}
+
+func TestDoublyLink_DeleteAtHead(t *testing.T) {
+	assert := internal.NewAssert(t, "TestDoublyLink_DeleteAtHead")
+
+	link := NewDoublyLink[int]()
+	err := link.DeleteAtHead()
+	assert.IsNotNil(err)
+
+	link.InsertAtTail(1)
+	link.InsertAtTail(2)
+	link.InsertAtTail(3)
+	link.InsertAtTail(4)
+
+	link.DeleteAtHead()
+	link.Print()
+
+	expected := []int{2, 3, 4}
+	values := link.Values()
+
+	assert.Equal(expected, values)
+}
+
+func TestDoublyLink_DeleteAtTail(t *testing.T) {
+	assert := internal.NewAssert(t, "TestDoublyLink_DeleteAtTail")
+
+	link := NewDoublyLink[int]()
+	err := link.DeleteAtTail()
+	assert.IsNotNil(err)
+
+	link.InsertAtTail(1)
+	link.InsertAtTail(2)
+	link.InsertAtTail(3)
+	link.InsertAtTail(4)
+
+	link.DeleteAtTail()
+	link.Print()
+
+	expected := []int{1, 2, 3}
+	values := link.Values()
+
+	assert.Equal(expected, values)
+}
+
+func TestDoublyLink_DeleteAt(t *testing.T) {
+	assert := internal.NewAssert(t, "TestDoublyLink_DeleteAt")
+
+	link := NewDoublyLink[int]()
+	err := link.DeleteAt(0)
+	assert.IsNotNil(err)
+
+	link.InsertAtTail(1)
+	link.InsertAtTail(2)
+	link.InsertAtTail(3)
+	link.InsertAtTail(4)
+	link.InsertAtTail(5)
+
+	err = link.DeleteAt(5)
+	assert.IsNotNil(err)
+
+	err = link.DeleteAt(0)
+	assert.IsNil(err)
+	assert.Equal([]int{2, 3, 4, 5}, link.Values())
+
+	link.DeleteAt(3)
+	assert.Equal([]int{2, 3, 4}, link.Values())
+
+	link.DeleteAt(1)
+	assert.Equal(2, link.Size())
+	assert.Equal([]int{2, 4}, link.Values())
+}
+
+func TestDoublyLink_Reverse(t *testing.T) {
+	assert := internal.NewAssert(t, "TestDoublyLink_Reverse")
+
+	link := NewDoublyLink[int]()
+	link.InsertAtTail(1)
+	link.InsertAtTail(2)
+	link.InsertAtTail(3)
+	link.InsertAtTail(4)
+
+	link.Reverse()
+	link.Print()
+	assert.Equal([]int{4, 3, 2, 1}, link.Values())
+}
+
+func TestDoublyLink_GetMiddleNode(t *testing.T) {
+	assert := internal.NewAssert(t, "TestDoublyLink_GetMiddleNode")
+
+	link := NewDoublyLink[int]()
+	link.InsertAtTail(1)
+	link.InsertAtTail(2)
+	link.InsertAtTail(3)
+	link.InsertAtTail(4)
+
+	middle1 := link.GetMiddleNode()
+	assert.Equal(3, middle1.Value)
+
+	link.InsertAtTail(5)
+	link.InsertAtTail(6)
+	link.InsertAtTail(7)
+	middle2 := link.GetMiddleNode()
+	assert.Equal(4, middle2.Value)
+}