add merge-sort for go

Author: dok

solutions/go/merge-sort.go

@@ -0,0 +1,52 @@
+package main
+
+import (
+  "fmt"
+  "math"
+)
+
+func mergeSort(ary []int) []int {
+  if len(ary) <= 1 {
+    return ary
+  }
+  left := make([]int, 0)
+  right := make([]int, 0)
+  middle := math.Floor(float64(len(ary) / 2))
+
+  left = ary[0:int(middle)]
+  right = ary[int(middle):]
+
+  return merge(mergeSort(left), mergeSort(right))
+}
+
+func merge(left, right []int) []int {
+
+  result := make([]int, 0)
+
+  for len(left) > 0 || len(right) > 0 {
+    if len(left) > 0 && len(right) > 0 {
+      if left[0] <= right[0] {
+        result = append(result, left[0])
+        left = left[1:len(left)]
+      } else {
+        result = append(result, right[0])
+        right = right[1:len(right)]
+      }
+    } else if len(left) > 0 {
+      result = append(result, left[0])
+      left = left[1:len(left)]
+    } else {
+      result = append(result, right[0])
+      right = right[1:len(right)]
+    }
+  }
+
+  return result
+}
+
+func main() {
+  random := []int{1,73,7,1,72,58,933,574,24,74,52}
+  fmt.Println("Unsorted: ", random)
+  random = mergeSort(random)
+  fmt.Println("Sorted: ", random)
+}