refactor: rewrite sort function

2026-02-04 12:52:28 +08:00 · 2022-04-12 14:30:43 +08:00
parent 5483380066
commit 5d6f9443fd
2 changed files with 104 additions and 83 deletions
--- a/algorithm/sorter.go
+++ b/algorithm/sorter.go
@@ -7,7 +7,7 @@ package algorithm
 import "github.com/duke-git/lancet/v2/lancetconstraints"

 // BubbleSort use bubble to sort slice.
-func BubbleSort[T any](slice []T, comparator lancetconstraints.Comparator) []T {
+func BubbleSort[T any](slice []T, comparator lancetconstraints.Comparator) {
 	for i := 0; i < len(slice); i++ {
 		for j := 0; j < len(slice)-1-i; j++ {
 			isCurrGreatThanNext := comparator.Compare(slice[j], slice[j+1]) == 1
@@ -16,38 +16,26 @@ func BubbleSort[T any](slice []T, comparator lancetconstraints.Comparator) []T {
 			}
 		}
 	}
-	return slice
 }

 // InsertionSort use insertion to sort slice.
-func InsertionSort[T any](slice []T, comparator lancetconstraints.Comparator) []T {
-	size := len(slice)
-	if size <= 1 {
-		return slice
-	}
-
-	for i := 1; i < size; i++ {
-		currentItem := slice[i]
-		preIndex := i - 1
-		preItem := slice[preIndex]
-
-		isPreLessThanCurrent := comparator.Compare(preItem, currentItem) == -1
-		for preIndex >= 0 && isPreLessThanCurrent {
-			slice[preIndex+1] = slice[preIndex]
-			preIndex--
+func InsertionSort[T any](slice []T, comparator lancetconstraints.Comparator) {
+	for i := 0; i < len(slice); i++ {
+		for j := i; j > 0; j-- {
+			isPreLessThanCurrent := comparator.Compare(slice[j], slice[j-1]) == -1
+			if isPreLessThanCurrent {
+				swap(slice, j, j-1)
+			} else {
+				break
+			}
 		}
-
-		slice[preIndex+1] = currentItem
 	}
-
-	return slice
 }

 // SelectionSort use selection to sort slice.
-func SelectionSort[T any](slice []T, comparator lancetconstraints.Comparator) []T {
+func SelectionSort[T any](slice []T, comparator lancetconstraints.Comparator) {
 	for i := 0; i < len(slice); i++ {
 		min := i
-
 		for j := i + 1; j < len(slice); j++ {
 			if comparator.Compare(slice[j], slice[min]) == -1 {
 				min = j
@@ -55,15 +43,11 @@ func SelectionSort[T any](slice []T, comparator lancetconstraints.Comparator) []
 		}
 		swap(slice, i, min)
 	}
-	return slice
 }

 // ShellSort shell sort slice.
-func ShellSort[T any](slice []T, comparator lancetconstraints.Comparator) []T {
+func ShellSort[T any](slice []T, comparator lancetconstraints.Comparator) {
 	size := len(slice)
-	if size <= 1 {
-		return slice
-	}

 	gap := 1
 	for gap < size/3 {
@@ -76,21 +60,17 @@ func ShellSort[T any](slice []T, comparator lancetconstraints.Comparator) []T {
 				swap(slice, j, j-gap)
 			}
 		}
-		gap /= 3
+		gap = gap / 3
 	}
-
-	return slice
 }

 // QuickSort quick sorting for slice, lowIndex is 0 and highIndex is len(slice)-1
-func QuickSort[T any](slice []T, lowIndex, highIndex int, comparator lancetconstraints.Comparator) []T {
+func QuickSort[T any](slice []T, lowIndex, highIndex int, comparator lancetconstraints.Comparator) {
 	if lowIndex < highIndex {
 		p := partition(slice, lowIndex, highIndex, comparator)
 		QuickSort(slice, lowIndex, p-1, comparator)
 		QuickSort(slice, p+1, highIndex, comparator)
 	}
-
-	return slice
 }

 // partition split slice into two parts
@@ -110,7 +90,7 @@ func partition[T any](slice []T, lowIndex, highIndex int, comparator lancetconst
 }

 // HeapSort use heap to sort slice
-func HeapSort[T any](slice []T, comparator lancetconstraints.Comparator) []T {
+func HeapSort[T any](slice []T, comparator lancetconstraints.Comparator) {
 	size := len(slice)

 	for i := size/2 - 1; i >= 0; i-- {
@@ -120,8 +100,6 @@ func HeapSort[T any](slice []T, comparator lancetconstraints.Comparator) []T {
 		swap(slice, 0, j)
 		sift(slice, 0, j-1, comparator)
 	}
-
-	return slice
 }

 func sift[T any](slice []T, lowIndex, highIndex int, comparator lancetconstraints.Comparator) {
@@ -145,15 +123,17 @@ func sift[T any](slice []T, lowIndex, highIndex int, comparator lancetconstraint
 }

 // MergeSort merge sorting for slice
-func MergeSort[T any](slice []T, lowIndex, highIndex int, comparator lancetconstraints.Comparator) []T {
+func MergeSort[T any](slice []T, comparator lancetconstraints.Comparator) {
+	mergeSort(slice, 0, len(slice)-1, comparator)
+}
+
+func mergeSort[T any](slice []T, lowIndex, highIndex int, comparator lancetconstraints.Comparator) {
 	if lowIndex < highIndex {
 		mid := (lowIndex + highIndex) / 2
-		MergeSort(slice, lowIndex, mid, comparator)
-		MergeSort(slice, mid+1, highIndex, comparator)
+		mergeSort(slice, lowIndex, mid, comparator)
+		mergeSort(slice, mid+1, highIndex, comparator)
 		merge(slice, lowIndex, mid, highIndex, comparator)
 	}
-
-	return slice
 }

 func merge[T any](slice []T, lowIndex, midIndex, highIndex int, comparator lancetconstraints.Comparator) {
--- a/algorithm/sorter_test.go
+++ b/algorithm/sorter_test.go
@@ -28,22 +28,15 @@ func (pc *peopleAgeComparator) Compare(v1 any, v2 any) int {
 		return 1
 	}
 	return 0
-
-	//decending order
-	// if p1.Age > p2.Age {
-	// 	return -1
-	// } else if p1.Age < p2.Age {
-	// 	return 1
-	// }
 }

-var peoples = []people{
-	{Name: "a", Age: 20},
-	{Name: "b", Age: 10},
-	{Name: "c", Age: 17},
-	{Name: "d", Age: 8},
-	{Name: "e", Age: 28},
-}
+// var peoples = []people{
+// 	{Name: "a", Age: 20},
+// 	{Name: "b", Age: 10},
+// 	{Name: "c", Age: 17},
+// 	{Name: "d", Age: 8},
+// 	{Name: "e", Age: 28},
+// }

 type intComparator struct{}

@@ -60,40 +53,51 @@ func (c *intComparator) Compare(v1 any, v2 any) int {
 	return 0
 }

-var intSlice = []int{2, 1, 5, 3, 6, 4}
+// var intSlice = []int{2, 1, 5, 3, 6, 4}

 func TestBubbleSortForStructSlice(t *testing.T) {
 	asssert := internal.NewAssert(t, "TestBubbleSortForStructSlice")

+	peoples := []people{
+		{Name: "a", Age: 20},
+		{Name: "b", Age: 10},
+		{Name: "c", Age: 17},
+		{Name: "d", Age: 8},
+		{Name: "e", Age: 28},
+	}
 	comparator := &peopleAgeComparator{}
-	sortedPeopleByAge := BubbleSort(peoples, comparator)
-	t.Log(sortedPeopleByAge)
+	BubbleSort(peoples, comparator)

 	expected := "[{d 8} {b 10} {c 17} {a 20} {e 28}]"
-	actual := fmt.Sprintf("%v", sortedPeopleByAge)
+	actual := fmt.Sprintf("%v", peoples)

 	asssert.Equal(expected, actual)
 }

 func TestBubbleSortForIntSlice(t *testing.T) {
 	asssert := internal.NewAssert(t, "TestBubbleSortForIntSlice")
-
+	numbers := []int{2, 1, 5, 3, 6, 4}
 	comparator := &intComparator{}
-	sortedInt := BubbleSort(intSlice, comparator)
-	expected := []int{1, 2, 3, 4, 5, 6}
+	BubbleSort(numbers, comparator)

-	asssert.Equal(expected, sortedInt)
+	asssert.Equal([]int{1, 2, 3, 4, 5, 6}, numbers)
 }

 func TestInsertionSort(t *testing.T) {
 	asssert := internal.NewAssert(t, "TestInsertionSort")

+	peoples := []people{
+		{Name: "a", Age: 20},
+		{Name: "b", Age: 10},
+		{Name: "c", Age: 17},
+		{Name: "d", Age: 8},
+		{Name: "e", Age: 28},
+	}
 	comparator := &peopleAgeComparator{}
-	sortedPeopleByAge := InsertionSort(peoples, comparator)
-	t.Log(sortedPeopleByAge)
+	InsertionSort(peoples, comparator)

-	expected := "[{e 28} {a 20} {c 17} {b 10} {d 8}]"
-	actual := fmt.Sprintf("%v", sortedPeopleByAge)
+	expected := "[{d 8} {b 10} {c 17} {a 20} {e 28}]"
+	actual := fmt.Sprintf("%v", peoples)

 	asssert.Equal(expected, actual)
 }
@@ -101,12 +105,18 @@ func TestInsertionSort(t *testing.T) {
 func TestSelectionSort(t *testing.T) {
 	asssert := internal.NewAssert(t, "TestSelectionSort")

+	peoples := []people{
+		{Name: "a", Age: 20},
+		{Name: "b", Age: 10},
+		{Name: "c", Age: 17},
+		{Name: "d", Age: 8},
+		{Name: "e", Age: 28},
+	}
 	comparator := &peopleAgeComparator{}
-	sortedPeopleByAge := SelectionSort(peoples, comparator)
-	t.Log(sortedPeopleByAge)
+	SelectionSort(peoples, comparator)

 	expected := "[{d 8} {b 10} {c 17} {a 20} {e 28}]"
-	actual := fmt.Sprintf("%v", sortedPeopleByAge)
+	actual := fmt.Sprintf("%v", peoples)

 	asssert.Equal(expected, actual)
 }
@@ -114,12 +124,18 @@ func TestSelectionSort(t *testing.T) {
 func TestShellSort(t *testing.T) {
 	asssert := internal.NewAssert(t, "TestShellSort")

+	peoples := []people{
+		{Name: "a", Age: 20},
+		{Name: "b", Age: 10},
+		{Name: "c", Age: 17},
+		{Name: "d", Age: 8},
+		{Name: "e", Age: 28},
+	}
 	comparator := &peopleAgeComparator{}
-	sortedPeopleByAge := ShellSort(peoples, comparator)
-	t.Log(sortedPeopleByAge)
+	ShellSort(peoples, comparator)

 	expected := "[{d 8} {b 10} {c 17} {a 20} {e 28}]"
-	actual := fmt.Sprintf("%v", sortedPeopleByAge)
+	actual := fmt.Sprintf("%v", peoples)

 	asssert.Equal(expected, actual)
 }
@@ -127,12 +143,18 @@ func TestShellSort(t *testing.T) {
 func TestQuickSort(t *testing.T) {
 	asssert := internal.NewAssert(t, "TestQuickSort")

+	peoples := []people{
+		{Name: "a", Age: 20},
+		{Name: "b", Age: 10},
+		{Name: "c", Age: 17},
+		{Name: "d", Age: 8},
+		{Name: "e", Age: 28},
+	}
 	comparator := &peopleAgeComparator{}
-	sortedPeopleByAge := QuickSort(peoples, 0, len(peoples)-1, comparator)
-	t.Log(sortedPeopleByAge)
+	QuickSort(peoples, 0, len(peoples)-1, comparator)

 	expected := "[{d 8} {b 10} {c 17} {a 20} {e 28}]"
-	actual := fmt.Sprintf("%v", sortedPeopleByAge)
+	actual := fmt.Sprintf("%v", peoples)

 	asssert.Equal(expected, actual)
 }
@@ -140,12 +162,18 @@ func TestQuickSort(t *testing.T) {
 func TestHeapSort(t *testing.T) {
 	asssert := internal.NewAssert(t, "TestHeapSort")

+	peoples := []people{
+		{Name: "a", Age: 20},
+		{Name: "b", Age: 10},
+		{Name: "c", Age: 17},
+		{Name: "d", Age: 8},
+		{Name: "e", Age: 28},
+	}
 	comparator := &peopleAgeComparator{}
-	sortedPeopleByAge := HeapSort(peoples, comparator)
-	t.Log(sortedPeopleByAge)
+	HeapSort(peoples, comparator)

 	expected := "[{d 8} {b 10} {c 17} {a 20} {e 28}]"
-	actual := fmt.Sprintf("%v", sortedPeopleByAge)
+	actual := fmt.Sprintf("%v", peoples)

 	asssert.Equal(expected, actual)
 }
@@ -153,12 +181,18 @@ func TestHeapSort(t *testing.T) {
 func TestMergeSort(t *testing.T) {
 	asssert := internal.NewAssert(t, "TestMergeSort")

+	peoples := []people{
+		{Name: "a", Age: 20},
+		{Name: "b", Age: 10},
+		{Name: "c", Age: 17},
+		{Name: "d", Age: 8},
+		{Name: "e", Age: 28},
+	}
 	comparator := &peopleAgeComparator{}
-	sortedPeopleByAge := MergeSort(peoples, 0, len(peoples)-1, comparator)
-	t.Log(sortedPeopleByAge)
+	MergeSort(peoples, comparator)

 	expected := "[{d 8} {b 10} {c 17} {a 20} {e 28}]"
-	actual := fmt.Sprintf("%v", sortedPeopleByAge)
+	actual := fmt.Sprintf("%v", peoples)

 	asssert.Equal(expected, actual)
 }
@@ -166,6 +200,13 @@ func TestMergeSort(t *testing.T) {
 func TestCountSort(t *testing.T) {
 	asssert := internal.NewAssert(t, "TestCountSort")

+	peoples := []people{
+		{Name: "a", Age: 20},
+		{Name: "b", Age: 10},
+		{Name: "c", Age: 17},
+		{Name: "d", Age: 8},
+		{Name: "e", Age: 28},
+	}
 	comparator := &peopleAgeComparator{}
 	sortedPeopleByAge := CountSort(peoples, comparator)
 	t.Log(sortedPeopleByAge)