golang https://tour.go-zh.org/methods/12

Posted 2021-05-24

package main

import (
	"io"
	"os"
	"strings"
)

type rot13Reader struct {
	r io.Reader
}

func (rot *rot13Reader) Read(b []byte) (int, error) {

	n, err := rot.r.Read(b)
	for i := 0; i < len(b); i++ {
		v, ok := Map[b[i]]
		if ok {
			b[i] = v
		}
	}
	return n, err
}

var Map map[byte]byte

func init_map() {
	Map = make(map[byte]byte)
	input := "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
	output := "NOPQRSTUVWXYZABCDEFGHIJKLMnopqrstuvwxyzabcdefghijklm"
	for n, _ := range input {
		Map[input[n]] = output[n]
	}
}

func main() {
	init_map()
	s := strings.NewReader("Lbh penpxrq gur pbqr!")
	r := rot13Reader{s}
	io.Copy(os.Stdout, &r)
}

go实现等价二叉查找树

地址：https://tour.go-zh.org/concurrency/7

code：

package main

import (
	"golang.org/x/tour/tree"
	"fmt"
	//"strconv"
)

// Walk 步进 tree t 将所有的值从 tree 发送到 channel ch。
func Walk(t *tree.Tree, ch chan int) {
	if t == nil {
		return
	}
	if t.Left != nil {
		Walk(t.Left, ch)		
	}
	//fmt.Println(t.Value)
	ch <- t.Value
	if t.Right != nil {
		Walk(t.Right, ch)
	}
	return
}

// Same 检测树 t1 和 t2 是否含有相同的值。
func Same(t1, t2 *tree.Tree) bool {
	ch0 := make(chan int, 15)
	ch1 := make(chan int, 15)
	Walk(t1, ch0)
	close(ch0)
	Walk(t2, ch1)
	close(ch1)
	l0 := len(ch0)
	l1 := len(ch1)
	if l0 != l1 {
		return false;
	}
	for i := 0; i < l0; i++ {
		if <-ch0 != <-ch1 {
			return false
		}
		//fmt.Println("ch0:" + strconv.Itoa(<-ch0))
	}
	//for i := 0; i < l1; i++ {
	//	fmt.Println("ch1:" + strconv.Itoa(<-ch1))
	//}
	return true
}

func main() {
	tree0 := tree.New(2)
	tree1 := tree.New(2)
	ret := Same(tree0, tree1)
	fmt.Println(ret)
}