merge and quick sort

Author: gcaggia

Diff for: sort_merge.go

@@ -0,0 +1,48 @@
+package main
+
+import (
+	"fmt"
+	utils "../golang-algorithms/utils"
+)
+
+func merge(arr[] int, iLeft, iMiddle, iRight int)  {
+	// We need a tmp array
+	var arrTmp[] int
+	// basic variables
+	i, j := iLeft, iMiddle + 1
+
+	for k := iLeft; k <= iRight; k++ {
+		if i <= iMiddle && j <= iRight {
+			if arr[i] < arr[j] {
+				arrTmp, i = append(arrTmp, arr[i]), i + 1
+			} else {
+				arrTmp, j = append(arrTmp, arr[j]), j + 1
+			}
+		} else {
+			if i > iMiddle {
+				arrTmp, j = append(arrTmp, arr[j]), j + 1
+			} else {
+				arrTmp, i = append(arrTmp, arr[i]), i + 1
+			}
+		}
+	}
+	for k, l := iLeft, 0; l < len(arrTmp) ; k, l = k + 1, l + 1  {
+		arr[k] = arrTmp[l]
+	}
+}
+
+func mergeSort(arr[] int, iLeft int, iRight int)  {
+	if iLeft < iRight {
+		var iMiddle int = ( iLeft + iRight ) / 2
+		mergeSort(arr, iLeft, iMiddle)
+		mergeSort(arr, iMiddle + 1, iRight)
+		merge(arr, iLeft, iMiddle, iRight)
+	}
+}
+
+func main() {
+	arr := utils.RandomIntArray(10)
+	fmt.Println("Array before: ", arr)
+	mergeSort(arr, 0, len(arr) - 1)
+	fmt.Println("Array after:  ", arr)
+}

Diff for: sort_quick.go

@@ -0,0 +1,33 @@
+package main
+
+import (
+	"fmt"
+	utils "../golang-algorithms/utils"
+)
+
+func pivot(arr[] int, iLeft int, iRight int) (iPivot int) {
+	iPivot = iLeft
+	for i, valInitPivot :=iLeft + 1, arr[iLeft] ; i <= iRight; i++  {
+		if arr[i] < valInitPivot {
+			iPivot++
+			arr[i], arr[iPivot] = arr[iPivot], arr[i]
+		}
+	}
+	arr[iPivot], arr[iLeft] = arr[iLeft], arr[iPivot]
+	return
+}
+
+func quickSort(arr[] int, iLeft int, iRight int)  {
+	if iLeft < iRight {
+		iPivot := pivot(arr, iLeft, iRight)
+		quickSort(arr, iLeft, iPivot)
+		quickSort(arr, iPivot + 1, iRight)
+	}
+}
+
+func main() {
+	arr := utils.RandomIntArray(10)
+	fmt.Println("Array before: ", arr)
+	quickSort(arr, 0, len(arr) - 1)
+	fmt.Println("Array after:  ", arr)
+}