Add Merge Sort

.travis.yml

@@ -15,5 +15,6 @@ script:
   cd ../InterpolationSearch && go test ./;
   cd ../JumpSearch && go test ./;
   cd ../LinearSearch && go test ./;
+  cd ../MergeSort && go test ./;
   cd ../SelectionSort && go test ./;
   cd ../TernarySearch && go test ./;

MergeSort/MergeSort.go

@@ -0,0 +1,45 @@
+package MergeSort
+
+func mergeParts(array []int, leftIndex, divideIndex, rightIndex int) {
+	var tempArray1, tempArray2 []int
+	for i := leftIndex; i <= divideIndex; i++ {
+		tempArray1 = append(tempArray1, array[i])
+	}
+	for i := divideIndex + 1; i <= rightIndex; i++ {
+		tempArray2 = append(tempArray2, array[i])
+	}
+	arrayIndex := leftIndex
+	tempArray1Index := 0
+	tempArray2Index := 0
+	for tempArray1Index != len(tempArray1) && tempArray2Index != len(tempArray2) {
+		if tempArray1[tempArray1Index] <= tempArray2[tempArray2Index] {
+			array[arrayIndex] = tempArray1[tempArray1Index]
+			tempArray1Index += 1
+		} else {
+			array[arrayIndex] = tempArray2[tempArray2Index]
+			tempArray2Index += 1
+		}
+		arrayIndex += 1
+	}
+	for tempArray1Index < len(tempArray1) {
+		array[arrayIndex] = tempArray1[tempArray1Index]
+		tempArray1Index += 1
+		arrayIndex += 1
+
+	}
+	for tempArray2Index < len(tempArray2) {
+		array[arrayIndex] = tempArray2[tempArray2Index]
+		tempArray2Index += 1
+		arrayIndex += 1
+	}
+}
+
+func MergeSort(array []int, leftIndex, rightIndex int) {
+	if leftIndex >= rightIndex {
+		return
+	}
+	divideIndex := int((leftIndex + rightIndex) / 2)
+	MergeSort(array, leftIndex, divideIndex)
+	MergeSort(array, divideIndex+1, rightIndex)
+	mergeParts(array, leftIndex, divideIndex, rightIndex)
+}

MergeSort/MergeSort_test.go

@@ -0,0 +1,25 @@
+package MergeSort
+
+import (
+	"math/rand"
+	"sort"
+	"testing"
+	"time"
+)
+
+func TestSelectionSort(t *testing.T) {
+	random := rand.New(rand.NewSource(time.Now().UnixNano()))
+	array1 := make([]int, random.Intn(100-10)+10)
+	for i := range array1 {
+		array1[i] = random.Intn(100)
+	}
+	array2 := make(sort.IntSlice, len(array1))
+	copy(array2, array1)
+	MergeSort(array1, 0, len(array1)-1)
+	array2.Sort()
+	for i := range array1 {
+		if array1[i] != array2[i] {
+			t.Fail()
+		}
+	}
+}

README.md

@@ -32,6 +32,7 @@ There are several data structures and algorithms implemented in this project. Th
 - Comb Sort
 - Cocktail Sort
 - Gnome Sort
+- Merge Sort
 
 ## Usage