B树的构造
// a binary tree
// node, two child nodes(left, right)
// nodes with children are parent node.
// child nodes may contain references to their parents.
package main
import (
"fmt"
"io"
"log"
)
type BinaryNode struct {
left *BinaryNode
right *BinaryNode
data int64
}
type BinaryTree struct {
root *BinaryNode
}
type d struct {
}
func (d) Write(p []byte) (int, error) {
log.Println("----------", string(p))
return 0, nil
}
func (t *BinaryTree) insert(data int64) *BinaryTree {
if t.root == nil {
t.root = &BinaryNode{data: data, left: nil, right: nil}
} else {
t.root.insert(data)
}
return t
}
func (n *BinaryNode) insert(data int64) {
if n == nil {
return
} else if data <= n.data {
if n.left == nil {
n.left = &BinaryNode{data: data, left: nil, right: nil}
} else {
n.left.insert(data)
}
} else {
if n.right == nil {
n.right = &BinaryNode{data: data, left: nil, right: nil}
} else {
n.right.insert(data)
}
}
}
func print(w io.Writer, node *BinaryNode, ns int, ch rune) {
if node == nil {
return
}
for i := 0; i < ns; i++ {
// fmt.Print(w, " ")
}
fmt.Fprintf(w, "%c:%v
", ch, node.data)
print(w, node.left, ns+2, 'L')
print(w, node.right, ns+2, 'R')
}
func main() {
tree := &BinaryTree{}
tree.insert(100).
insert(-20).
insert(90).
insert(80).
insert(-50)
var dins d = d{}
print(dins, tree.root, 0, 'M')
}