whatcanGOwrong

go/pkg/mod/github.com/go-delve/delve@v1.23.0/_fixtures/binarytrees.go

@@ -0,0 +1,96 @@
+/* The Computer Language Benchmarks Game
+ * http://benchmarksgame.alioth.debian.org/
+ *
+ * based on Go program by The Go Authors.
+ * based on C program by Kevin Carson
+ * flag.Arg hack by Isaac Gouy
+ * modified by Jamil Djadala to use goroutines
+ * modified by Chai Shushan
+ *
+ */
+
+package main
+
+import (
+	"flag"
+	"fmt"
+	"runtime"
+	"strconv"
+	"sync"
+)
+
+var minDepth = 4
+var n = 20
+
+func main() {
+	runtime.GOMAXPROCS(runtime.NumCPU() * 2)
+
+	flag.Parse()
+	if flag.NArg() > 0 {
+		n, _ = strconv.Atoi(flag.Arg(0))
+	}
+
+	maxDepth := n
+	if minDepth+2 > n {
+		maxDepth = minDepth + 2
+	}
+	stretchDepth := maxDepth + 1
+
+	check_l := bottomUpTree(0, stretchDepth).ItemCheck()
+	fmt.Printf("stretch tree of depth %d\t check: %d\n", stretchDepth, check_l)
+
+	longLivedTree := bottomUpTree(0, maxDepth)
+
+	result_trees := make([]int, maxDepth+1)
+	result_check := make([]int, maxDepth+1)
+
+	var wg sync.WaitGroup
+	for depth_l := minDepth; depth_l <= maxDepth; depth_l += 2 {
+		wg.Add(1)
+		go func(depth int) {
+			iterations := 1 << uint(maxDepth-depth+minDepth)
+			check := 0
+
+			for i := 1; i <= iterations; i++ {
+				check += bottomUpTree(i, depth).ItemCheck()
+				check += bottomUpTree(-i, depth).ItemCheck()
+			}
+			result_trees[depth] = iterations * 2
+			result_check[depth] = check
+
+			wg.Done()
+		}(depth_l)
+	}
+	wg.Wait()
+
+	for depth := minDepth; depth <= maxDepth; depth += 2 {
+		fmt.Printf("%d\t trees of depth %d\t check: %d\n",
+			result_trees[depth], depth, result_check[depth],
+		)
+	}
+	fmt.Printf("long lived tree of depth %d\t check: %d\n",
+		maxDepth, longLivedTree.ItemCheck(),
+	)
+}
+
+func bottomUpTree(item, depth int) *Node {
+	if depth <= 0 {
+		return &Node{item, nil, nil}
+	}
+	return &Node{item,
+		bottomUpTree(2*item-1, depth-1),
+		bottomUpTree(2*item, depth-1),
+	}
+}
+
+type Node struct {
+	item        int
+	left, right *Node
+}
+
+func (self *Node) ItemCheck() int {
+	if self.left == nil {
+		return self.item
+	}
+	return self.item + self.left.ItemCheck() - self.right.ItemCheck()
+}