add shellsort and refactor a bit

1 files changed, 37 insertions, 6 deletions

diff --git a/ds/integer.go b/ds/integer.go
index 69ee0aa..b8026da 100644
--- a/ds/integer.go
+++ b/ds/integer.go
@@ -1,25 +1,56 @@
 package ds
 
-import "math/rand"
+import (
+	"fmt"
+	"math/rand"
+)
 
-type Integer int
+type Integer struct {
+	val int
+}
 
 func RandomIntegers(length, max int) []Comparer {
 	a := make([]Comparer, length)
 	for i := 0; i < length; i++ {
-		a[i] = Integer(rand.Intn(max))
+		a[i] = Integer{rand.Intn(max)}
 	}
 	return a
 }
 
+func SortedIntegers(length int) []Comparer {
+	a := make([]Comparer, length)
+	for i := 0; i < length; i++ {
+		a[i] = Integer{i}
+	}
+	return a
+}
+
+func ReverseSortedIntegers(length int) []Comparer {
+	a := make([]Comparer, length)
+	j := length
+	for i := 0; i < length; i++ {
+		a[i] = Integer{j}
+		j--
+	}
+	return a
+}
+
+func (i Integer) String() string {
+	return fmt.Sprintf("%d", i.val)
+}
+
+func (i Integer) IntVal() int {
+	return i.val
+}
+
 func (i Integer) LowerThan(j Comparer) bool {
-	return i < j.(Integer)
+	return i.val < j.IntVal()
 }
 
 func (i Integer) HigherThan(j Comparer) bool {
-	return i > j.(Integer)
+	return i.val > j.IntVal()
 }
 
 func (i Integer) Equals(j Comparer) bool {
-	return i == j.(Integer)
+	return i.val == j.IntVal()
 }