fix shell sort

6 files changed, 29 insertions, 18 deletions

diff --git a/ds/comparer.go b/ds/comparer.go
index 168ec19..8fb3727 100644
--- a/ds/comparer.go
+++ b/ds/comparer.go
@@ -1,8 +1,10 @@
 package ds
 
 type Comparer interface {
-	LowerThan(a Comparer) bool
-	HigherThan(a Comparer) bool
-	Equals(a Comparer) bool
-	IntVal() int
+	Equal(a Comparer) bool
+	Lower(a Comparer) bool
+	LowerEqual(a Comparer) bool
+	Higher(a Comparer) bool
+	HigherEqual(a Comparer) bool
+	Int() int
 }
diff --git a/ds/integer.go b/ds/integer.go
index b8026da..336a941 100644
--- a/ds/integer.go
+++ b/ds/integer.go
@@ -39,18 +39,26 @@ func (i Integer) String() string {
 	return fmt.Sprintf("%d", i.val)
 }
 
-func (i Integer) IntVal() int {
+func (i Integer) Int() int {
 	return i.val
 }
 
-func (i Integer) LowerThan(j Comparer) bool {
-	return i.val < j.IntVal()
+func (i Integer) Equal(j Comparer) bool {
+	return i.val == j.Int()
 }
 
-func (i Integer) HigherThan(j Comparer) bool {
-	return i.val > j.IntVal()
+func (i Integer) Lower(j Comparer) bool {
+	return i.val < j.Int()
 }
 
-func (i Integer) Equals(j Comparer) bool {
-	return i.val == j.IntVal()
+func (i Integer) LowerEqual(j Comparer) bool {
+	return i.val <= j.Int()
+}
+
+func (i Integer) Higher(j Comparer) bool {
+	return i.val > j.Int()
+}
+
+func (i Integer) HigherEqual(j Comparer) bool {
+	return i.val >= j.Int()
 }
diff --git a/sort/insertion.go b/sort/insertion.go
index d14c275..8e4af30 100644
--- a/sort/insertion.go
+++ b/sort/insertion.go
@@ -9,7 +9,7 @@ func Insertion(a []ds.Comparer) []ds.Comparer {
 
 	for i := 0; i < length; i++ {
 		for j := i; j > 0; j-- {
-			if a[j].HigherThan(a[j-1]) {
+			if a[j].Higher(a[j-1]) {
 				break
 			}
 			tmp := a[j]
diff --git a/sort/selection.go b/sort/selection.go
index 2782460..d084fc0 100644
--- a/sort/selection.go
+++ b/sort/selection.go
@@ -9,7 +9,7 @@ func Selection(a []ds.Comparer) []ds.Comparer {
 	for i := 0; i < length; i++ {
 		min := i
 		for j := i + 1; j < length; j++ {
-			if a[min].HigherThan(a[j]) {
+			if a[min].Higher(a[j]) {
 				min = j
 			}
 		}
diff --git a/sort/shell.go b/sort/shell.go
index 99aaf3d..39414f5 100644
--- a/sort/shell.go
+++ b/sort/shell.go
@@ -17,11 +17,12 @@ func Shell(a []ds.Comparer) []ds.Comparer {
 	for h >= 1 {
 		for i := h; i < length; i++ {
 			for j := i; j >= h; j -= h {
-				if a[j].LowerThan(a[j-h]) {
-					tmp := a[j]
-					a[j] = a[j-h]
-					a[j-h] = tmp
+				if a[j-h].Lower(a[j]) {
+					break
 				}
+				tmp := a[j]
+				a[j] = a[j-h]
+				a[j-h] = tmp
 			}
 		}
 
diff --git a/sort/sorted.go b/sort/sorted.go
index a24de19..b29e3c6 100644
--- a/sort/sorted.go
+++ b/sort/sorted.go
@@ -4,7 +4,7 @@ import "algorithms/ds"
 
 func Sorted(a []ds.Comparer) bool {
 	for i := len(a) - 1; i > 0; i-- {
-		if a[i].LowerThan(a[i-1]) {
+		if a[i].Lower(a[i-1]) {
 			return false
 		}
 	}