Add go merge sort

go/merge_sort.go

@@ -0,0 +1,73 @@
+package main
+
+import (
+	"fmt"
+)
+
+var list = []int{1, 55, 3, 6, 4, 95, 23, 57, 2, 8, 5}
+
+func Merge(a, b []int) []int {
+	result := make([]int, len(a)+len(b))
+
+	n1 := len(a)
+	n2 := len(b)
+
+	var i, j, k int
+
+	for i < n1 && j < n2 {
+		if a[i] < b[j] {
+			result[k] = a[i]
+			i++
+		} else {
+			result[k] = b[j]
+			j++
+
+		}
+		k++
+	}
+
+	for i < n1 {
+		result[k] = a[i]
+		k++
+		i++
+	}
+
+	for j < n2 {
+		result[k] = b[j]
+		k++
+		j++
+	}
+
+	return result
+}
+
+func Sort(unsorted []int) []int {
+	result := make([]int, len(unsorted))
+
+	if len(unsorted) == 1 {
+		result[0] = unsorted[0]
+	} else {
+		i := 0
+		j := 1
+		if unsorted[0] > unsorted[1] {
+			i, j = j, i
+		}
+		result[0], result[1] = unsorted[i], unsorted[j]
+	}
+
+	return result
+}
+
+func MergeSort(unsorted []int) []int {
+	if len(unsorted) <= 2 {
+		return Sort(unsorted)
+	}
+	half := len(unsorted) / 2
+
+	return Merge(MergeSort(unsorted[0:half]), MergeSort(unsorted[half:len(unsorted)]))
+}
+
+func main() {
+	fmt.Println(list)
+	fmt.Println(MergeSort(list))
+}