Merge branch 'mattany-master'

Fix merge conflicts. Modify new file for insertion sort and delete old file.

Author: Mystigan

sorts/heap_sort.go

@@ -33,7 +33,7 @@ func (h maxHeap) MaxHeapify(i int) {
 
 func (h maxHeap) size() int { return h.heapSize } // ???
 
-func heapSort(slice []int) []int {
+func HeapSort(slice []int) []int {
 	h := buildMaxHeap(slice)
 	//log.Println(slice)
 	for i := len(h.slice) - 1; i >= 1; i-- {

sorts/insertionsort.go renamed to sorts/insertion_sort.go

@@ -1,8 +1,7 @@
-// Reference: https://en.wikipedia.org/wiki/Insertion_sort
-
+//Package sorts a package for demonstrating sorting algorithms in Go
 package sorts
 
-func insertionSort(arr []int) []int {
+func InsertionSort(arr []int) []int {
 	for currentIndex := 1; currentIndex < len(arr); currentIndex++ {
 		temporary := arr[currentIndex]
 		iterator := currentIndex

sorts/quick_sort.go

@@ -5,7 +5,7 @@ import (
 	"math/rand"
 )
 
-func quickSort(arr []int) []int {
+func QuickSort(arr []int) []int {
 
 	if len(arr) <= 1 {
 		return arr
@@ -28,8 +28,8 @@ func quickSort(arr []int) []int {
 		}
 	}
 
-	lowPart = quickSort(lowPart)
-	highPart = quickSort(highPart)
+	lowPart = QuickSort(lowPart)
+	highPart = QuickSort(highPart)
 
 	lowPart = append(lowPart, middlePart...)
 	lowPart = append(lowPart, highPart...)

sorts/radix_sort.go

@@ -0,0 +1,60 @@
+package sorts
+
+func max(arr []int) int {
+	max := arr[0]
+	for _, item := range arr {
+		if item > max {
+			max = item
+		}
+	}
+	return max
+}
+
+func countSort(arr []int, exp int) []int {
+	var digits [10]int
+	var output = make([]int, len(arr))
+
+	for _, item := range arr {
+		digits[(item/exp)%10]++
+	}
+	for i := 1; i < 10; i++ {
+		digits[i] += digits[i-1]
+	}
+
+	for i := len(arr) - 1; i >= 0; i-- {
+		output[digits[(arr[i]/exp)%10]-1] = arr[i]
+		digits[(arr[i]/exp)%10]--
+	}
+
+	return output
+}
+
+func unsignedRadixSort(arr []int) []int {
+	if len(arr) == 0 {
+		return arr
+	}
+	maxElement := max(arr)
+	for exp := 1; maxElement/exp > 0; exp *= 10 {
+		arr = countSort(arr, exp)
+	}
+	return arr
+}
+
+func RadixSort(arr []int) []int {
+	var negatives, nonNegatives []int
+
+	for _, item := range arr {
+		if item < 0 {
+			negatives = append(negatives, -item)
+		} else {
+			nonNegatives = append(nonNegatives, item)
+		}
+	}
+	negatives = unsignedRadixSort(negatives)
+
+	// Reverse the negative array and restore signs
+	for i, j := 0, len(negatives)-1; i <= j; i, j = i+1, j-1 {
+		negatives[i], negatives[j] = -negatives[j], -negatives[i]
+	}
+	return append(negatives, unsignedRadixSort(nonNegatives)...)
+}

sorts/selection_sort.go

@@ -1,7 +1,7 @@
 //Package sorts a package for demonstrating sorting algorithms in Go
 package sorts
 
-func selectionSort(arr []int) []int {
+func SelectionSort(arr []int) []int {
 
 	for i := 0; i < len(arr); i++ {
 		min := i

sorts/shell_sort.go

@@ -1,7 +1,7 @@
 //Package sorts a package for demonstrating sorting algorithms in Go
 package sorts
 
-func shellSort(arr []int) []int {
+func ShellSort(arr []int) []int {
 	for d := int(len(arr) / 2); d > 0; d /= 2 {
 		for i := d; i < len(arr); i++ {
 			for j := i; j >= d && arr[j-d] > arr[j]; j -= d {

sorts/sorts_case_test.go

@@ -13,25 +13,45 @@ type sortTest struct {
 	name     string
 }
 
-var arr []int = makeRandArray(500_000)
+var uarr []int = makeRandomUnsignedSlice(500_000)
+var arr []int = makeRandomSignedSlice(500_000)
 
 var sortTests = []sortTest{
 	//Sorted slice
 	{[]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10},
-		[]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, "Sorted"},
+		[]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, "Sorted Unsigned"},
 	//Reversed slice
 	{[]int{10, 9, 8, 7, 6, 5, 4, 3, 2, 1},
-		[]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, "Reversed"},
+		[]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, "Reversed Unsigned"},
+	//500k unsigned int values sort
+	{uarr, getSortedVersion(uarr), "Large Random Unsigned"},
+
+	//Sorted slice
+	{[]int{-10, -9, -8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10},
+		[]int{-10, -9, -8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, "Sorted Signed"},
+
+	//Reversed slice
+	{[]int{10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0, -1, -2, -3, -4, -5, -6, -7, -8, -9, -10},
+		[]int{-10, -9, -8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, "Reversed Signed"},
+
+	//Reversed slice, even length
+	{[]int{10, 9, 8, 7, 6, 5, 4, 3, 2, 1, -1, -2, -3, -4, -5, -6, -7, -8, -9, -10},
+		[]int{-10, -9, -8, -7, -6, -5, -4, -3, -2, -1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, "Reversed Signed #2"},
+
+	//Random order with repetitions
+	{[]int{-5, 7, 4, -2, 6, 5, 8, 3, 2, -7, -1, 0, -3, 9, -6, -4, 10, 9, 1, -8, -9, -10},
+		[]int{-10, -9, -8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 9, 10}, "Random order Signed"},
+
+	//500k int values sort
+	{arr, getSortedVersion(arr), "Large Random Signed"},
+
 	//Empty slice
 	{[]int{}, []int{}, "Empty"},
 	//Single-entry slice
 	{[]int{1}, []int{1}, "Singleton"},
-
-	//500k values sort
-	{arr, getSortedVersion(arr), "Large Random"},
 }
 
-func makeRandArray(size int) []int {
+func makeRandomUnsignedSlice(size int) []int {
 	vals := make([]int, size)
 	for i := 0; i < size; i++ {
 		temp, _ := rand.Int(rand.Reader, big.NewInt(int64(size)))
@@ -40,6 +60,15 @@ func makeRandArray(size int) []int {
 	return vals
 }
 
+func makeRandomSignedSlice(size int) []int {
+	vals := make([]int, size)
+	for i := 0; i < size; i++ {
+		temp, _ := rand.Int(rand.Reader, big.NewInt(int64(size)))
+		vals[i] = int(temp.Int64()) - 250_000
+	}
+	return vals
+}
+
 func getSortedVersion(a []int) []int {
 	sort.Slice(a, func(i, j int) bool { return a[i] < a[j] })
 	return a