diff --git a/huffman_test.go b/huffman_test.go
index a5ca063..289b82f 100644
--- a/huffman_test.go
+++ b/huffman_test.go
@@ -1,6 +1,7 @@
 package huffman
 
 import (
+	"bytes"
 	"fmt"
 	"testing"
 
@@ -49,6 +50,12 @@ func TestBuildTree0(t *testing.T) {
 	assert.Equal(t, int64(2), n.r.l.l.key)
 	assert.Equal(t, int64(3), n.r.l.r.key)
 	assert.Equal(t, int64(6), n.r.r.key)
+
+	w := bytes.NewBufferString("")
+	printTree(w, n)
+	if debug {
+		fmt.Println(w)
+	}
 }
 
 func TestBuildTree1(t *testing.T) {
@@ -68,6 +75,12 @@ func TestBuildTree1(t *testing.T) {
 	assert.Equal(t, int64(58), n.key)
 	assert.Equal(t, int64(25), n.l.key)
 	assert.Equal(t, int64(33), n.r.key)
+
+	w := bytes.NewBufferString("")
+	printTree(w, n)
+	if debug {
+		fmt.Println(w)
+	}
 }
 
 func TestGenerateTable(t *testing.T) {
diff --git a/utils.go b/utils.go
new file mode 100644
index 0000000..5d1c48c
--- /dev/null
+++ b/utils.go
@@ -0,0 +1,24 @@
+package huffman
+
+import (
+	"fmt"
+	"io"
+)
+
+func printNode(w io.Writer, n *Node) {
+	if n.typ == MID {
+		fmt.Fprintf(w, "\"%v\" -> {\"%v\" \"%v\"}\n", n.String(), n.l.String(), n.r.String())
+		printNode(w, n.l)
+		printNode(w, n.r)
+	} else if n.typ == LEAF {
+		fmt.Fprintf(w, "\"%v\" [style=filled];\n", n.String())
+	}
+}
+func printTree(w io.Writer, n *Node) {
+	fmt.Fprintf(w, `digraph hierarchy {
+		node [fontname=Monospace,fontsize=10,shape=box]
+		`)
+
+	printNode(w, n)
+	fmt.Fprintf(w, "}\n")
+}