iterative Find()

README.md

@@ -204,9 +204,9 @@ goos: linux
 goarch: amd64
 pkg: github.com/gaissmai/interval
 cpu: Intel(R) Core(TM) i5-8250U CPU @ 1.60GHz
-BenchmarkFind/In100-8               11051197       102.8 ns/op      0 B/op    0 allocs/op
-BenchmarkFind/In1_000-8             12076317        99.6 ns/op      0 B/op    0 allocs/op
-BenchmarkFind/In10_000-8             8264806       145.3 ns/op      0 B/op    0 allocs/op
-BenchmarkFind/In100_000-8            2878986       412.3 ns/op      0 B/op    0 allocs/op
-BenchmarkFind/In1_000_000-8          4449298       263.9 ns/op      0 B/op    0 allocs/op
+BenchmarkFind/In100-8               17299449        63.9 ns/op      0 B/op    0 allocs/op
+BenchmarkFind/In1_000-8             17327350        69.4 ns/op      0 B/op    0 allocs/op
+BenchmarkFind/In10_000-8            12858908        90.2 ns/op      0 B/op    0 allocs/op
+BenchmarkFind/In100_000-8            4696676       256.7 ns/op      0 B/op    0 allocs/op
+BenchmarkFind/In1_000_000-8          7131028       163.1 ns/op      0 B/op    0 allocs/op
 ```

bench_test.go

@@ -48,7 +48,7 @@ func BenchmarkInsertMutable(b *testing.B) {
 }
 
 func BenchmarkDelete(b *testing.B) {
-	for n := 10; n <= 1_000_000; n *= 10 {
+	for n := 1; n <= 1_000_000; n *= 10 {
 		ivals := generateIvals(n)
 		probe := ivals[rand.Intn(len(ivals))]
 
@@ -65,7 +65,7 @@ func BenchmarkDelete(b *testing.B) {
 }
 
 func BenchmarkDeleteMutable(b *testing.B) {
-	for n := 10; n <= 1_000_000; n *= 10 {
+	for n := 1; n <= 1_000_000; n *= 10 {
 		ivals := generateIvals(n)
 		probe := ivals[rand.Intn(len(ivals))]
 
@@ -112,7 +112,7 @@ func BenchmarkUnionMutable(b *testing.B) {
 }
 
 func BenchmarkFind(b *testing.B) {
-	for n := 100; n <= 1_000_000; n *= 10 {
+	for n := 1; n <= 1_000_000; n *= 10 {
 		ivals := generateIvals(n)
 		tree := interval.NewTree(ivals...)
 		probe := ivals[rand.Intn(len(ivals))]

treap.go

@@ -62,12 +62,8 @@ func makeNode[T Interface[T]](item T) *node[T] {
 
 // copyNode, make a shallow copy of the pointers and the item, no recalculation necessary.
 func (n *node[T]) copyNode() *node[T] {
-	if n == nil {
-		return n
-	}
-
-	m := *n
-	return &m
+	c := *n
+	return &c
 }
 
 // Insert elements into the tree, returns the new Tree.
@@ -293,33 +289,21 @@ func (t *node[T]) split(key T, immutable bool) (left, mid, right *node[T]) {
 // otherwise the zero value for item and false.
 func (t Tree[T]) Find(item T) (result T, ok bool) {
 	n := t.root
-	return n.find(item)
-}
-
-func (n *node[T]) find(item T) (result T, ok bool) {
-	// recursion stop condition(s)
-	if n == nil {
-		return
-	}
-
-	// fast exit, node has too small max upper interval value (augmented value)
-	if item.CompareUpper(n.maxUpper.item) > 0 {
-		return
-	}
-
-	cmp := compare(item, n.item)
-	if cmp == 0 {
-		return n.item, true
-	}
+	for {
+		if n == nil {
+			return
+		}
 
-	// rec-descent
-	switch {
-	case cmp < 0:
-		return n.left.find(item)
-	case cmp > 0:
-		return n.right.find(item)
+		cmp := compare(item, n.item)
+		switch {
+		case cmp == 0:
+			return n.item, true
+		case cmp < 0:
+			n = n.left
+		case cmp > 0:
+			n = n.right
+		}
 	}
-	panic("unreachable")
 }
 
 // Shortest returns the most specific interval that covers item. ok is true on

treap_test.go

@@ -69,6 +69,10 @@ func TestNewTree(t *testing.T) {
 		t.Errorf("FprintBST(w) = %v, want \"\"", w.String())
 	}
 
+	if _, ok := zeroTree.Find(zeroItem); ok {
+		t.Errorf("Find(), got: %v, want: false", ok)
+	}
+
 	if _, ok := zeroTree.Delete(zeroItem); ok {
 		t.Errorf("Delete(), got: %v, want: false", ok)
 	}