day7函数 递归 递归练习题

go.mod

@@ -1,3 +1,5 @@
 module Study
 
 go 1.19
+
+require golang.org/x/net v0.2.0 // indirect

go.sum

@@ -0,0 +1,2 @@
+golang.org/x/net v0.2.0 h1:sZfSu1wtKLGlWI4ZZayP0ck9Y73K1ynO6gqzTdBVdPU=
+golang.org/x/net v0.2.0/go.mod h1:KqCZLdyyvdV855qA2rE3GC2aiw5xGR5TEjj8smXukLY=

src/study/day3/server1.go

@@ -8,7 +8,7 @@ import (
 
 func main() {
 	http.HandleFunc("/", handler1)
-	log.Fatal(http.ListenAndServe("localhost:8090", nil))
+	log.Fatal(http.ListenAndServe("localhost:8989", nil))
 }
 
 func handler1(w http.ResponseWriter, r *http.Request) {

src/study/day7Function/Practice5.1_5.4.go

@@ -0,0 +1,87 @@
+package main
+
+import (
+	"fmt"
+	"golang.org/x/net/html"
+	"log"
+	"net/http"
+)
+
+type man struct {
+	sex    bool
+	name   string
+	action func()
+}
+
+func main() {
+
+	var dug man
+	dug.name = "dugulingping"
+	dug.action = func() {
+		fmt.Println("Hi " + dug.name)
+	}
+	fmt.Printf("%T\n", dug.action)
+	dug.action()
+
+	resp, err := http.Get("https://golang-china.github.io/gopl-zh/ch5/ch5-02.html")
+	if err != nil {
+		log.Fatal(err)
+	}
+	if resp.StatusCode != http.StatusOK {
+		err := resp.Body.Close()
+		if err != nil {
+			log.Fatal(err)
+			return
+		}
+	}
+	doc, err := html.Parse(resp.Body)
+	if err != nil {
+		log.Fatal(err)
+		return
+	}
+	// 关闭链接
+	err = resp.Body.Close()
+	if err != nil {
+		log.Fatal(err)
+		return
+	}
+	node := make(map[string]int)
+	v(node, doc)
+	//fmt.Println(node)
+
+}
+
+func v(node map[string]int, n *html.Node) map[string]int {
+	if n == nil {
+		return node
+	}
+	if n.Type == html.ElementNode {
+		node[n.Data] += 1
+		//fmt.Println(n.Data)
+	}
+
+	if n.Type == html.TextNode {
+		if n.Data != "script" && n.Data != "style" {
+			//fmt.Println(n.Data)
+		}
+	}
+	node = v(node, n.FirstChild)
+	node = v(node, n.NextSibling)
+	return node
+}
+func v4(links []string, n *html.Node) []string {
+	if n == nil {
+		return links
+	}
+	if n.Type == html.ElementNode && (n.Data == "a" || n.Data == "images" || n.Data == "scripts") {
+		for _, a := range n.Attr {
+			if a.Key == "href" {
+				links = append(links, a.Val)
+				//fmt.Println(a.Val)
+			}
+		}
+	}
+	links = v4(links, n.FirstChild)
+	links = v4(links, n.NextSibling)
+	return links
+}

src/study/day7Function/Recursive.go

@@ -0,0 +1,59 @@
+package main
+
+// 递归，函数可以直接或间接的调用自身。
+// 对许多问题而言，递归是一种强有力的技术，
+// 例如处理递归的数据结构。
+
+import (
+	"fmt"
+	"os"
+
+	"golang.org/x/net/html"
+)
+
+func main() {
+	doc, err := html.Parse(os.Stdin)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "findlinks1: %v\n", err)
+		os.Exit(1)
+	}
+	//fmt.Println(doc.NextSibling.Data)
+	for _, link := range visit(nil, doc.FirstChild) {
+		fmt.Println(link)
+	}
+	//outline(nil, doc)
+}
+
+// visit appends to links each link found in n and returns the result.
+func visit(links []string, n *html.Node) []string {
+	if n == nil {
+		return links
+	}
+	if n.Type == html.ElementNode && n.Data == "a" {
+		for _, a := range n.Attr {
+			if a.Key == "href" {
+				links = append(links, a.Val)
+				//fmt.Println(a.Val)
+			}
+		}
+	}
+	//for c := n.FirstChild; c != nil; c = c.NextSibling {
+	//	links = visit(links, c)
+	//}
+	//if n != nil {
+	//	links = visit(links, n.NextSibling)
+	//}
+	links = visit(links, n.FirstChild)
+	links = visit(links, n.NextSibling)
+	return links
+}
+func outline(stack []string, n *html.Node) []string {
+	if n.Type == html.ElementNode {
+		stack = append(stack, n.Data)
+		fmt.Println(stack)
+	}
+	for c := n.FirstChild; c != nil; c = c.NextSibling {
+		outline(stack, c)
+	}
+	return stack
+}