Add problem 75 - Sort Colors

Author: anirudhology

problems/array/sort_colors.go

@@ -0,0 +1,20 @@
+package array
+
+func SortColors(nums []int) []int {
+	// Pointers to keep track of 0s, 1s and 2s
+	left, middle, right := 0, 0, len(nums)-1
+	// Process elements in the array
+	for middle <= right {
+		if nums[middle] == 0 {
+			nums[middle], nums[left] = nums[left], nums[middle]
+			left += 1
+			middle += 1
+		} else if nums[middle] == 1 {
+			middle += 1
+		} else {
+			nums[middle], nums[right] = nums[right], nums[middle]
+			right -= 1
+		}
+	}
+	return nums
+}

tests/array/sort_colors_test.go

@@ -0,0 +1,71 @@
+package array_test
+
+import (
+	"reflect"
+	"testing"
+
+	"github.com/anirudhology/leetcode-go/problems/array"
+)
+
+func TestSortColors_AllZeros(t *testing.T) {
+	nums := []int{0, 0, 0}
+	expected := []int{0, 0, 0}
+	result := array.SortColors(nums)
+	if !reflect.DeepEqual(result, expected) {
+		t.Errorf("Expected %v but got %v", expected, result)
+	}
+}
+
+func TestSortColors_AllOnes(t *testing.T) {
+	nums := []int{1, 1, 1}
+	expected := []int{1, 1, 1}
+	result := array.SortColors(nums)
+	if !reflect.DeepEqual(result, expected) {
+		t.Errorf("Expected %v but got %v", expected, result)
+	}
+}
+
+func TestSortColors_AllTwos(t *testing.T) {
+	nums := []int{2, 2, 2}
+	expected := []int{2, 2, 2}
+	result := array.SortColors(nums)
+	if !reflect.DeepEqual(result, expected) {
+		t.Errorf("Expected %v but got %v", expected, result)
+	}
+}
+
+func TestSortColors_Mixed(t *testing.T) {
+	nums := []int{2, 0, 2, 1, 1, 0}
+	expected := []int{0, 0, 1, 1, 2, 2}
+	result := array.SortColors(nums)
+	if !reflect.DeepEqual(result, expected) {
+		t.Errorf("Expected %v but got %v", expected, result)
+	}
+}
+
+func TestSortColors_EmptyArray(t *testing.T) {
+	nums := []int{}
+	expected := []int{}
+	result := array.SortColors(nums)
+	if !reflect.DeepEqual(result, expected) {
+		t.Errorf("Expected %v but got %v", expected, result)
+	}
+}
+
+func TestSortColors_SingleElement(t *testing.T) {
+	nums := []int{1}
+	expected := []int{1}
+	result := array.SortColors(nums)
+	if !reflect.DeepEqual(result, expected) {
+		t.Errorf("Expected %v but got %v", expected, result)
+	}
+}
+
+func TestSortColors_AlreadySorted(t *testing.T) {
+	nums := []int{0, 1, 2}
+	expected := []int{0, 1, 2}
+	result := array.SortColors(nums)
+	if !reflect.DeepEqual(result, expected) {
+		t.Errorf("Expected %v but got %v", expected, result)
+	}
+}