code kata 230808

binary_tree_230807/main_test.go

@@ -0,0 +1,261 @@
+package main
+
+import (
+	"fmt"
+	"testing"
+)
+
+type node struct {
+	left  *node
+	right *node
+	value string
+}
+
+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 PreOrder22(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 InOrder22(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 PostOrder22(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 postOrder222(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 postOrder2222(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 TestPreOrder(t *testing.T) {
+	PreOrder(makeBinaryTree())
+}
+
+func TestPreOrder2(t *testing.T) {
+	PreOrder2(makeBinaryTree())
+}
+
+func TestPreOrder22(t *testing.T) {
+	PreOrder22(makeBinaryTree())
+}
+
+func TestInOrder(t *testing.T) {
+	InOrder(makeBinaryTree())
+}
+
+func TestInOrder2(t *testing.T) {
+	InOrder2(makeBinaryTree())
+}
+
+func TestInOrder22(t *testing.T) {
+	InOrder22(makeBinaryTree())
+}
+
+func TestPostOrder(t *testing.T) {
+	PostOrder(makeBinaryTree())
+}
+
+func TestPostOrder2(t *testing.T) {
+	PostOrder2(makeBinaryTree())
+}
+
+func TestPostOrder22(t *testing.T) {
+	PostOrder22(makeBinaryTree())
+}
+
+func TestPostOrder222(t *testing.T) {
+	postOrder222(makeBinaryTree())
+}
+
+func TestPostOrder2222(t *testing.T) {
+	postOrder2222(makeBinaryTree())
+}
+
+func visit(n *node) {
+	fmt.Printf("visiting node: %s\n", n.value)
+}
+
+func makeBinaryTree() *node {
+	return &node{
+		left: &node{
+			left: &node{
+				value: "D",
+			},
+			value: "B",
+		},
+		right: &node{
+			right: &node{
+				value: "E",
+			},
+			value: "C",
+		},
+		value: "A",
+	}
+}

binary_tree_230807/stack.go

@@ -0,0 +1,36 @@
+package main
+
+type Stack []interface {
+}
+
+func MakeStack() *Stack {
+	return &Stack{}
+}
+
+func (s Stack) IsEmpty() bool {
+	return len(s) == 0
+}
+
+func (s Stack) Len() int {
+	return len(s)
+}
+
+func (s Stack) Top() interface{} {
+	if s.IsEmpty() {
+		return nil
+	}
+	return s[len(s)-1]
+}
+
+func (s *Stack) Push(item interface{}) {
+	*s = append(*s, item)
+}
+
+func (s *Stack) Pop() interface{} {
+	if s.IsEmpty() {
+		return nil
+	}
+	ret := (*s)[len(*s)-1]
+	*s = (*s)[:(len(*s) - 1)]
+	return ret
+}