add bench helper

4 files changed, 55 insertions, 6 deletions

diff --git a/sort/bench.go b/sort/bench.go
new file mode 100644
index 0000000..094debd
--- /dev/null
+++ b/sort/bench.go
@@ -0,0 +1,21 @@
+package sort
+
+import (
+	"algorithms/ds"
+	"fmt"
+	"testing"
+)
+
+// Avoid compiler optimizations
+var benchResult []ds.Comparer
+
+func benchmark(name string, length int, sort func([]ds.Comparer) []ds.Comparer, b *testing.B) {
+	cb := func(b *testing.B) {
+		a := ds.RandomIntegers(length, length)
+		b.ResetTimer()
+		for i := 0; i < b.N; i++ {
+			benchResult = sort(a)
+		}
+	}
+	b.Run(fmt.Sprintf("Benchmark%s%d", name, length), cb)
+}
diff --git a/sort/insertion_test.go b/sort/insertion_test.go
index 4b503b8..afec414 100644
--- a/sort/insertion_test.go
+++ b/sort/insertion_test.go
@@ -5,8 +5,16 @@ import (
 	"testing"
 )
 
-func BenchmarkInsertion1000(b *testing.B) {
+func BenchmarkInsertion(b *testing.B) {
+	benchmark("Insertion", 10, Insertion, b)
+	benchmark("Insertion", 100, Insertion, b)
+	benchmark("Insertion", 1000, Insertion, b)
+}
+
+func TestInsertion1000(t *testing.T) {
 	a := ds.RandomIntegers(1000, 1000)
-	b.ResetTimer()
-	Insertion(a)
+	a = Insertion(a)
+	if !Sorted(a) {
+		t.Errorf("Array not sorted: %v", a)
+	}
 }
diff --git a/sort/selection_test.go b/sort/selection_test.go
index 3881850..c5d6beb 100644
--- a/sort/selection_test.go
+++ b/sort/selection_test.go
@@ -5,8 +5,16 @@ import (
 	"testing"
 )
 
-func BenchmarkSelection1000(b *testing.B) {
+func BenchmarkSelection(b *testing.B) {
+	benchmark("Selection", 10, Selection, b)
+	benchmark("Selection", 100, Selection, b)
+	benchmark("Selection", 1000, Selection, b)
+}
+
+func TestSelection1000(t *testing.T) {
 	a := ds.RandomIntegers(1000, 1000)
-	b.ResetTimer()
-	Selection(a)
+	a = Selection(a)
+	if !Sorted(a) {
+		t.Errorf("Array not sorted: %v", a)
+	}
 }
diff --git a/sort/sorted.go b/sort/sorted.go
new file mode 100644
index 0000000..a24de19
--- /dev/null
+++ b/sort/sorted.go
@@ -0,0 +1,12 @@
+package sort
+
+import "algorithms/ds"
+
+func Sorted(a []ds.Comparer) bool {
+	for i := len(a) - 1; i > 0; i-- {
+		if a[i].LowerThan(a[i-1]) {
+			return false
+		}
+	}
+	return true
+}