binary_search.go

package main

import (
	"fmt"
)

type TreeNode struct {
	Val int
	Left *TreeNode
	Right *TreeNode
}

func (t *TreeNode) Insert(node *TreeNode) {
	if node.Val > t.Val {
		if t.Right == nil { 
			t.Right = node 
		} else {
			t.Right.Insert(node)
		}
	} else {
		if t.Left == nil { 
			t.Left = node 
		} else {
			t.Left.Insert(node)
		}
	}
}

func (t *TreeNode) Find(i int) *TreeNode {
	fmt.Printf("Processing %v\n", t)
	if i == t.Val {
		return t
	} else if i > t.Val && t.Right != nil{
		return t.Right.Find(i)
	} else if i < t.Val && t.Left != nil{
		return t.Left.Find(i)
	} else {
		return nil
	}
}

func main() {
	tree := &TreeNode{Val: 2}
	for _, n := range [...]int{2,1,4,3,5,1,3,1,9} {
		tree.Insert(&TreeNode{Val: n})
	}

	fmt.Printf("Finding 9: %v\n", tree.Find(9))
	fmt.Printf("Finding 10: %v\n", tree.Find(10))
}