code kata 230811

code_kata_230810/binary_tree_test.go

@@ -0,0 +1,168 @@
+package main
+
+import (
+	"fmt"
+	"testing"
+)
+
+func preOrder(n *node) {
+	if n == nil {
+		return
+	}
+	visit(n)
+	preOrder(n.left)
+	preOrder(n.right)
+}
+
+func preOrder2(n *node) {
+	stack := MakeStack()
+	p := n
+	for p != nil || !stack.IsEmpty() {
+		if p != nil {
+			visit(p)
+			stack.Push(p)
+			p = p.left
+		} else {
+			p = stack.Pop().(*node)
+			p = p.right
+		}
+	}
+}
+
+func inOrder(n *node) {
+	if n == nil {
+		return
+	}
+	inOrder(n.left)
+	visit(n)
+	inOrder(n.right)
+}
+
+func inOrder2(n *node) {
+	stack := MakeStack()
+	p := n
+	for p != nil || !stack.IsEmpty() {
+		if p != nil {
+			stack.Push(p)
+			p = p.left
+		} else {
+			p = stack.Pop().(*node)
+			visit(p)
+			p = p.right
+		}
+	}
+}
+
+func postOrder(n *node) {
+	if n == nil {
+		return
+	}
+	postOrder(n.left)
+	postOrder(n.right)
+	visit(n)
+}
+
+func postOrder2(n *node) {
+	stack := MakeStack()
+	p := n
+	var r *node = nil
+	for p != nil || !stack.IsEmpty() {
+		if p != nil {
+			stack.Push(p)
+			p = p.left
+		} else {
+			p = stack.Top().(*node)
+			if p.right != nil && p.right != r {
+				p = p.right
+				stack.Push(p)
+				p = p.left
+			} else {
+				p = stack.Pop().(*node)
+				visit(p)
+				r = p
+				p = nil
+			}
+		}
+	}
+}
+
+func levelOrder(n *node) {
+	queue := MakeQueue()
+	p := n
+	queue.EnQueue(p)
+	for !queue.IsEmpty() {
+		p = queue.DeQueue().(*node)
+		visit(p)
+		if p.left != nil {
+			queue.EnQueue(p.left)
+		}
+		if p.right != nil {
+			queue.EnQueue(p.right)
+		}
+	}
+}
+
+func TestPreOrder(t *testing.T) {
+	preOrder(makeBinaryTree())
+}
+
+func TestPreOrder2(t *testing.T) {
+	preOrder2(makeBinaryTree())
+}
+
+func TestInOrder(t *testing.T) {
+	inOrder(makeBinaryTree())
+}
+
+func TestInOrder2(t *testing.T) {
+	inOrder2(makeBinaryTree())
+}
+
+func TestPostOrder(t *testing.T) {
+	postOrder(makeBinaryTree())
+}
+
+func TestPostOrder2(t *testing.T) {
+	postOrder2(makeBinaryTree())
+}
+
+func TestLevelOrder(t *testing.T) {
+	levelOrder(makeBinaryTree())
+}
+
+type node struct {
+	left  *node
+	right *node
+	value string
+}
+
+func visit(n *node) {
+	if n == nil {
+		panic("invalid node")
+	}
+	fmt.Printf("Visiting node %s\n", n.value)
+}
+
+func makeBinaryTree() *node {
+	return &node{
+		left: &node{
+			left: &node{
+				value: "D",
+			},
+			right: &node{
+				value: "E",
+			},
+			value: "B",
+		},
+		right: &node{
+			left: &node{
+				value: "F",
+			},
+			right: &node{
+				value: "G",
+			},
+			value: "C",
+		},
+		value: "A",
+	}
+}