Merge pull request #717 from bohemian997/master

Added "Merge Sort Algorithm" in Golang in Go Directory

Author: probot-auto-merge[bot]

Go/merge_sort.go

@@ -0,0 +1,76 @@
+// Merge Sort in Golang
+package main
+
+import (
+	"fmt"
+	"math/rand"
+	"time"
+)
+
+func main() {
+
+	slice := generateSlice(20)
+	fmt.Println("\n--- Unsorted --- \n\n", slice)
+	fmt.Println("\n--- Sorted ---\n\n", mergeSort(slice))
+}
+
+// Generates a slice of size, size filled with random numbers
+func generateSlice(size int) []int {
+
+	slice := make([]int, size, size)
+	rand.Seed(time.Now().UnixNano())
+	for i := 0; i < size; i++ {
+		slice[i] = rand.Intn(999) - rand.Intn(999)
+	}
+	return slice
+}
+
+func mergeSort(items []int) []int {
+	var num = len(items)
+
+	if num == 1 {
+		return items
+	}
+
+	middle := int(num / 2)
+	var (
+		left  = make([]int, middle)
+		right = make([]int, num-middle)
+	)
+	for i := 0; i < num; i++ {
+		if i < middle {
+			left[i] = items[i]
+		} else {
+			right[i-middle] = items[i]
+		}
+	}
+
+	return merge(mergeSort(left), mergeSort(right))
+}
+
+func merge(left, right []int) (result []int) {
+	result = make([]int, len(left)+len(right))
+
+	i := 0
+	for len(left) > 0 && len(right) > 0 {
+		if left[0] < right[0] {
+			result[i] = left[0]
+			left = left[1:]
+		} else {
+			result[i] = right[0]
+			right = right[1:]
+		}
+		i++
+	}
+
+	for j := 0; j < len(left); j++ {
+		result[i] = left[j]
+		i++
+	}
+	for j := 0; j < len(right); j++ {
+		result[i] = right[j]
+		i++
+	}
+
+	return
+}