2-B-1, 2-B-2

2-B-1/main_test.go

@@ -0,0 +1,75 @@
+package algo
+
+import (
+	"fmt"
+	"math/rand"
+	"testing"
+)
+
+type testCase struct {
+	t1 []int
+	t2 []int
+	e1 []int
+	e2 []int
+}
+
+func randomCase(rng *rand.Rand, n int) testCase {
+	tc := testCase{
+		t1: make([]int, n),
+		t2: make([]int, n),
+		e1: make([]int, n),
+		e2: make([]int, n),
+	}
+
+	for i := 0; i < n; i++ {
+		tc.t1[i] = rng.Intn(1000)
+		tc.t2[i] = rng.Intn(1000)
+		tc.e1[i] = rng.Intn(1000)
+		tc.e2[i] = rng.Intn(1000)
+	}
+
+	return tc
+}
+
+func TestRecAndDPMatchOnRandomData(t *testing.T) {
+	rng := rand.New(rand.NewSource(1))
+	const casesPerLen = 200
+
+	for n := 1; n <= 128; n++ {
+		for caseIdx := 0; caseIdx < casesPerLen; caseIdx++ {
+			tc := randomCase(rng, n)
+			gotRec := Rec(tc.t1, tc.t2, tc.e1, tc.e2)
+			gotDP := DP(tc.t1, tc.t2, tc.e1, tc.e2)
+			if gotRec != gotDP {
+				t.Fatalf("mismatch for len=%d case=%d: Rec=%d DP=%d t1=%v t2=%v e1=%v e2=%v",
+					n, caseIdx, gotRec, gotDP, tc.t1, tc.t2, tc.e1, tc.e2)
+			}
+		}
+	}
+}
+
+func BenchmarkDP(b *testing.B) {
+	benchmarkByLen(b, "DP", DP)
+}
+
+func BenchmarkRec(b *testing.B) {
+	benchmarkByLen(b, "Rec", Rec)
+}
+
+func benchmarkByLen(b *testing.B, name string, fn func([]int, []int, []int, []int) int) {
+	lengths := []int{1, 10, 100, 1000, 10000, 100000, 1000000, 10000000}
+
+	for _, n := range lengths {
+		n := n
+		b.Run(fmt.Sprintf("%s/len=%d", name, n), func(b *testing.B) {
+			rng := rand.New(rand.NewSource(int64(n)))
+			tc := randomCase(rng, n)
+
+			b.ReportAllocs()
+			b.ResetTimer()
+			for i := 0; i < b.N; i++ {
+				_ = fn(tc.t1, tc.t2, tc.e1, tc.e2)
+			}
+		})
+	}
+}