练习题

水深无声 2023-06-02 13:57 88阅读 0赞

## Golang练习题 ##

HelloWorld

func main() {
        fmt.Println("HelloWorld")
    }

99乘法表

func main() {
        for i := 1;i<10;i++ {
            for j := 1;i<=i;j++ {
                fmt.Println("%d * %d = %d\t",j,i,j*i)
            }
        fmt.Println()
    }

质数判断

func justfy(a int) bool {
        for i := 2;i<a;i++ {
            if a % i == 0{
                return false
            }
        }
        return true
    }
    func main() {
        for i:=2;i<100;i++ {
            if justfy(i) == true {
                fmt.Printf("[%d] is prime\n",i}
            }
        }
    }

水仙花数，1的立方+5的立方+3的立方=153

func shuixianhua(a int) bool {
        first := a%10
        second := (a/10)%10
        third := (a/100)%10
        sum := first*first*first+second*second*second+third*third*third
        if sum == a{
            return true
        }
        reutrn false
    }
    func main() {
        for i := 100;i<1000;i++{
            if shuixianhuashu(i) == true{
                fmt.Printf("[%d]是水仙花数\n",i)
            }
        }
    }

字符统计:：输入一行字符，统计出英文字母、空格、数字和其他字符的个数

func test(str string) (charCount,numCount,spaceCount,otherCount int) {
        uftChars := []rune(str)
        for i:= 0;i<len(uftChars);i++ {
            if uftChars[i] >= 'a' && uftChars[i] <= 'z' || uftChars[i] >= 'A' && uftChars[i] <= 'Z' {
                charCount++
                continue
            }
            if uftChars[i] >= '0' && uftChars[i] <='9' {
                numChount++
                continue
            }
            if uftChars[i] == ' '{
                spaceConut++
                continue
            }
            otherCount++}
        }
        return
    }
    func main() {
        var str string = "dksjfhk   我123+---"
        carCount,numCount,spCount,other := test(str)
        fmt.Printf("字母有%d,数字有%d,空格有%d,其他有%d", charCount, numCount, spCount, other)
    }

插入排序

func inser_sort(a [8]int) [8]int {
        for i:=1;i<len(a);i++ {
            for j:= i;j>0;j-- {
                if a[j] <a[j-1] {
                    a[j],a[j-1] = a[j-1],a[j]
                } else {
                    break
                }
            }
        }
        return a
    }
    func main() {
        var i [8]int = [8]int{8,3, 2, 9, 4, 6, 10, 0}
        j := inser_sort(i)
        fmt.Println(i)    //[8,3, 2, 9, 4, 6, 10, 0]
        fmt.Println(j)    //[0,2,3,4,6,8,9,10]
    }

选择排序

func selet_sort(a [8]int) [8]int {
        for i:=0;i<len(a);i++ {
            for j:= i+1;j<len(a);j++ {
                if a[j] < a[i] {
                    [i],a[j] = a[j],a[i]
                }
            }
        }
        return a
    }
    func main() {
        var i [8]int = [8]int{8, 3, 2, 9, 4, 6, 10, 0}
        j := select_sort(i)
        fmt.Println(i)    //[8, 3, 2, 9, 4, 6, 10, 0]
        fmt.Println(j)    //[0,2,3,4,6,8,9,10]
    }

斐波那锲数列

//递归
    func fab(n int) int{
        if n<=1 {
            return 1
        }
        return fab(n-1) + fab(n-2)
    }
    func main() {
        for i :=0;i<10;i++ {
            n:= fab(i)
            fmt.Println(n)
        }
    }

冒泡排序

func select_sort(a [8]int) [8]int{
        for i:= 0;i<len(a);i++ {
            for j:=0;j<len(a)-i-1;j++ {
                if a[j]>a[j+1]{
                    a[j],a[j+1] = a[j+1],a[j]
                }
            }
        }
        return a
    }
    func main() {
        var i [8]int = [8]int{8, 3, 2, 9, 4, 6, 10, 0}
        j := select_sort{i}
        fmt.Println(i)
        fmt.Println(j)
    }

数组元素之和

func main() {
        a := [...]int{1,3,5,6,8}
        b := 0
        for _,value := range a {
            b += value
        }
        fmt.Println(b)
    }

数组中和为给定值的两个元素的下标：数组\[1,3,4,8,7\]中找出和为8的下标分别是(0,4)和(1,2)

func main() {
        a := [...]int{1,2,3,4,5,8,4,4,2}
        for i:=0;i<len(a);i++ {
            for j:= i+1;j<len(a);j++ {
                if a[i]+a[j] == 8 {
                    fmt.Printf("(%d,%d)的和等于8\n",i,j)
                }
            }
        }
    }

切片程序输出

func main() {
        var sa = make([]string,5,10)
        for i := 0;i<5;i++ {
            sa = append(sa,fmt.Sprintf("%v",i))
        }
        fmt.Println(sa)
    }    //[     0,1,2,3,4,5,6,7,8,9]

sort排序包对数据进行排序

func main() {
        var a [5]int = [5]int{1,4,2,5,6}
        sort.Ints(a[:])    //Ints表示整型
        fmt.Println(a)
        var b [5]string = [5]string{"ac","ed","sd","fg"}
        sort.Strings(b[:])    //Strings表示字符串类型
        fmt.Println(b)
    }    //Float64表示浮点型

统计字符串中每个单词出现的次数

//端口
    func test(str string) map[string]int {
        var result mapp[string]int = make(map[string]int,128)
        words := strings.Split(str," "}
        for _,v := range words {
            count,ok := result[v]
            if !ok {
                result[v] = 1
            } else {
                result[v] = count+1
            }
        }
        return result
    }
    func main() {
        var str = "how do ou do?"
        result := test(str)
        fmt.Printf("result%v\n",result)
    }
    
    //文件
    type CharCount struct {
        ChCount INT
        NumCount int
        SpaceCount int
        OtherCount int
    }
    func main() {
        file,err := os.Open("c:/test.log")
        if err != nil {
            fmt.Println("read file err:",err)
            return
        }
        defer file.Close()
        var count CharCount
        reader := bufio.NewReader(file)
        for {
            str,err := reader.ReadString('\n')
            if err == io.EOF {
                break
            }
            if err == ! nil {
                fmt.printf("read file failed,err:%v",err)
                break
            }
            runeArr := []rune(str)
            for _,v := range runeArr {
                switch {
                case v > ='a' && v<='z':
                    fallthrouth    //满足这个条件的无条件执行下一个case内容
                case v >= 'A'&&v<='Z':
                    count.ChCount++
                case v==' '||v=='\t':
                    count.SpaceCount++
                case v>='0'&&v<='9':
                    count.NumCount++
                default:
                    count.OtherCount++
                }
            }
        }
        fmt.Printf("char count:%d\n",count.ChCount)
        fmt.Printf("num count:%d\n",count.NumCount)
        fmt.Printf("space count:%d\n",count.SpaceCount)
        fmt.Printf("other count:%d\n",count.OtherCount)
    }

存储学生信息

//学生有id、年龄、分数、需要方便通过id查到对应学生的信息
    func test() {
        var stuMap map[int]map[string]interface{}
        stuMap = make(map[int]map[string]interface{},16)
        var id = 1
        var name = "stu01"
        var score = 79.3
        var age = 19
        value,ok := stuMap[id]
        if !ok {
            value = make(map[string]interface{},8)
        }
        value["id"] = id
        value["name"] = name
        value["score"] = score
        value["age"] = age
        stuMap[id] = value
        fmt.Printf("stuMap:%v\n",stuMap)    //stuMap:map[1:mao[age:19 id:1 name:stu01 score:79.3]]    带#表示要输出类型
        fmt.Printf("stuMap:%#v\n",stuMap)    //stuMap:mao[int]mao[string]interface{}{1:map[string]interface{}{"age":18,"id":1,"name":"stu01","score":79.3}}
        for i:= 0;i<10;i++ {
            value,ok := stuMap[i]
            if !ok {
                value = make{map[string]interface{},8)
            }
            value["name"] = fmt.Sprintf("stu%d",i)
            value["id"] = i
            value["score"] = rand.Float32()*100.0
            value["age"] = rand.Intn(100)
            stuMap[i] = vaue
        }
        fmt.Println()
        for k,v := range stuMap {
            fmt.Printf("id=%d stu info = %#v\n",k,v)
        }
    }

struct链表：单向链表

//尾部添加
    type Student struct {
        Name string
        Age int
        Score float64
        next *Student
    }
    func trans(p *Student) {
        for p!= nil {
            fmt.Println(*p)
            p = p.next
        }
        fmt.Println()
    }
    func test() {
        var head Student
        head.Name = "yang"
        head.Age = 19
        head.Score 100.00
        var tail = &head
        for i:=0;i<5;i++ {
            stu := &Student{
                Name : fmt.Sprintf("stu%d",i),
                Age:rand.Intn(100)
                Score:rand.Float64() *100,
            }
            tail.next = stu
            tail = stu
        }
        trans(&head)
    }
    
    //头部添加
    type Stident struct {
        Name string
        Age int
        Score float64
        next *Student
    }
    func trans(p *Student) {
        for p!= nil {
            fmt.Println(*p)
            p = p.next
        }
        fmt.Println()
    }
    func test() {
        var head *Student = &Student{}
        head.Name = "hua"
        head.Age = 18
        head.Score = 100
        for i := 0;i<5;i++ {
            stu := Student{
                Name : fmt.Printf("stu%d",i),
                Age : rand.Intn(100),
                Score:rand.Float64() *100,
            }
            stu.next = head
            head = &stu
        }
        trans(head)
    }

defer练习

func f1() int{
        x:= 5
        defer func() {
            x++
        }()
        return x
    }
    func f2() (x int) {
        defer func() {
            x++
        }()
        return 5
    }
    func f3() (y int) {
        x := 5
        defer func() {
            x++
        }()
        return x
    }
    func f4() (x int) {
        defer func(x int) {
            x++
        }(x)
        return 5
    }
    func main () {
        fmt.Println(f1())    //5
        fmt.Println(f2())    //6
        fmt.Println(f3())    //5
        fmt.Println(f4())    //5
    }

并发引起的闭包

//问题
    var wg sync.WaitGroup
    func main() {
        wg.Add(1000)
        for i :=0;i<1000;i++ {
            go func() {
                fmt.Println(hello",i)
                wg.Done()
            }()
        }
        wg.Wait()
    }    //会有很多重复的1000，匿名函数中i存在调用外部变量的情况产生闭包
    
    //解决
    var wg synv.WaitGroup
    func main() {
        wg.Add1000）
        for i:=0;i<1000;i++ {
            go func(i int) {
                fmt.Println("hello",i)
                wg.Done()
            }(i)
        }
        wg.Wait()
    }    //把i传进去就会解决嗲用外部变量的问题

简单聊天机器人

package main
    import (
        "bufio"
        "fmt"
        "os"
        "strings"
    )
    func main() {
        //从标准输入读取数据
        inputReader := bufio.NewReader(os.Stdin)
        fmt.Println("Please input your name：")
        //读取数据直到遇见\n位置
        input, err := inputReader.ReadString('\n')
        if err != nil {
            fmt.Printf("An error occurred:%s\n", err)
            //异常错误后退出
            os.Exit(1)
    
        } else {
            //用切片操作删除最后的\n
            name := input[:len(input)-1]
            fmt.Printf("Hello,%s!What can i di for you?\n", name)
        }
        for {
            input, err = inputReader.ReadString('\n')
            if err != nil {
                fmt.Printf("An error occurred:%s\n", err)
                continue
            }
            input = input[:len(input)-1]
            //全部转换为小写
            input = strings.ToLower(input)
            switch input {
            case "":
                continue
            case "nothing", "bye":
                fmt.Println("Bye!")
                //正常退出
                os.Exit(0)
            default:
                fmt.Println("Sorry,I didn't catch you.")
    
            }
        }
    }

转载于:https://www.cnblogs.com/parallel-Y/p/11589816.html