1 files changed, 92 insertions, 0 deletions
diff --git a/test/bench/binary-tree.go b/test/bench/binary-tree.go
new file mode 100644
index 000000000..9f867d11a
--- /dev/null
+++ b/test/bench/binary-tree.go
@@ -0,0 +1,92 @@
+/*
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+    * Redistributions of source code must retain the above copyright
+    notice, this list of conditions and the following disclaimer.
+
+    * Redistributions in binary form must reproduce the above copyright
+    notice, this list of conditions and the following disclaimer in the
+    documentation and/or other materials provided with the distribution.
+
+    * Neither the name of "The Computer Language Benchmarks Game" nor the
+    name of "The Computer Language Shootout Benchmarks" nor the names of
+    its contributors may be used to endorse or promote products derived
+    from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.
+*/
+
+/* The Computer Language Benchmarks Game
+ * http://shootout.alioth.debian.org/
+ *
+ * contributed by The Go Authors.
+ * based on C program by Kevin Carson
+ */
+
+package main
+
+import (
+	"flag"
+	"fmt"
+)
+
+var n = flag.Int("n", 15, "depth")
+
+type Node struct {
+	item        int
+	left, right *Node
+}
+
+func bottomUpTree(item, depth int) *Node {
+	if depth <= 0 {
+		return &Node{item: item}
+	}
+	return &Node{item, bottomUpTree(2*item-1, depth-1), bottomUpTree(2*item, depth-1)}
+}
+
+func (n *Node) itemCheck() int {
+	if n.left == nil {
+		return n.item
+	}
+	return n.item + n.left.itemCheck() - n.right.itemCheck()
+}
+
+const minDepth = 4
+
+func main() {
+	flag.Parse()
+
+	maxDepth := *n
+	if minDepth+2 > *n {
+		maxDepth = minDepth + 2
+	}
+	stretchDepth := maxDepth + 1
+
+	check := bottomUpTree(0, stretchDepth).itemCheck()
+	fmt.Printf("stretch tree of depth %d\t check: %d\n", stretchDepth, check)
+
+	longLivedTree := bottomUpTree(0, maxDepth)
+
+	for depth := minDepth; depth <= maxDepth; depth += 2 {
+		iterations := 1 << uint(maxDepth-depth+minDepth)
+		check = 0
+
+		for i := 1; i <= iterations; i++ {
+			check += bottomUpTree(i, depth).itemCheck()
+			check += bottomUpTree(-i, depth).itemCheck()
+		}
+		fmt.Printf("%d\t trees of depth %d\t check: %d\n", iterations*2, depth, check)
+	}
+	fmt.Printf("long lived tree of depth %d\t check: %d\n", maxDepth, longLivedTree.itemCheck())
+}