refactor merge

2 files changed, 13 insertions, 12 deletions

diff --git a/sort/merge.go b/sort/merge.go
index 9ee788d..86eb315 100644
--- a/sort/merge.go
+++ b/sort/merge.go
@@ -6,33 +6,34 @@ import (
 
 func Merge(a ds.ArrayList) ds.ArrayList {
 	aux := make(ds.ArrayList, len(a))
-	mergeSort(a, aux, 0, len(a)-1)
+	mergeSort(a, aux)
 
 	return a
 }
 
-func mergeSort(a, aux ds.ArrayList, lo, hi int) {
-	if lo >= hi {
+func mergeSort(a, aux ds.ArrayList) {
+	length := len(a)
+	if length <= 1 {
 		return
 	}
-	mid := lo + (hi-lo)/2
 
-	mergeSort(a, aux, lo, mid)
-	mergeSort(a, aux, mid+1, hi)
-	merge(a, aux, lo, mid, hi)
+	mi := length / 2
+	mergeSort(a[0:mi], aux[0:mi])
+	mergeSort(a[mi:], aux[mi:])
+	merge(a, aux, 0, mi-1, length-1)
 }
 
-func merge(a, aux ds.ArrayList, lo, mid, hi int) {
+func merge(a, aux ds.ArrayList, lo, mi, hi int) {
 	for i := lo; i <= hi; i++ {
 		aux[i] = a[i]
 	}
 
 	i := lo
-	j := mid + 1
+	j := mi + 1
 
 	for k := lo; k <= hi; k++ {
 		switch {
-		case i > mid:
+		case i > mi:
 			a[k] = aux[j]
 			j++
 		case j > hi:
diff --git a/sort/parallelmerge.go b/sort/parallelmerge.go
index b6cf721..577d7c1 100644
--- a/sort/parallelmerge.go
+++ b/sort/parallelmerge.go
@@ -17,8 +17,8 @@ func parallelMerge(a, aux ds.ArrayList, lo, hi int) {
 	defer merge(a, aux, lo, mid, hi)
 
 	if hi-lo <= 1000 {
-		mergeSort(a, aux, lo, mid)
-		mergeSort(a, aux, mid+1, hi)
+		//mergeSort(a, aux, lo, mid)
+		//mergeSort(a, aux, mid+1, hi)
 		return
 	}