add draw rect and new surface

gogame/qsort/qsort.go

@@ -0,0 +1,37 @@
+package qsort
+
+import "math/rand"
+
+func QuickSort(slice []int) []int {
+	length := len(slice)
+
+	if length <= 1 {
+		sliceCopy := make([]int, length)
+		copy(sliceCopy, slice)
+		return sliceCopy
+	}
+
+	m := slice[rand.Intn(length)]
+
+	less := make([]int, 0, length)
+	middle := make([]int, 0, length)
+	more := make([]int, 0, length)
+
+	for _, item := range slice {
+		switch {
+		case item < m:
+			less = append(less, item)
+		case item == m:
+			middle = append(middle, item)
+		case item > m:
+			more = append(more, item)
+		}
+	}
+
+	less, more = QuickSort(less), QuickSort(more)
+
+	less = append(less, middle...)
+	less = append(less, more...)
+
+	return less
+}

gogame/qsort/qsort_test.go

@@ -0,0 +1,27 @@
+package qsort
+
+import (
+	"reflect"
+	"testing"
+)
+
+var testData = []struct {
+	input          []int
+	expectedOutput []int
+}{
+	{[]int{}, []int{}},
+	{[]int{42}, []int{42}},
+	{[]int{42, 23}, []int{23, 42}},
+	{[]int{23, 42, 32, 64, 12, 4}, []int{4, 12, 23, 32, 42, 64}},
+}
+
+func TestQuickSort(t *testing.T) {
+	for _, testCase := range testData {
+		actual := QuickSort(testCase.input)
+		expected := testCase.expectedOutput
+
+		if !reflect.DeepEqual(actual, expected) {
+			t.Errorf("%v != %v\n", actual, expected)
+		}
+	}
+}