Go语言学习笔记九--Go语言练习--判断素数(质数)--水仙花数--统计字符

一、判断素数(质数)

package main

import (
    "fmt"
    "math"
)
//判断是否是质数
func isParam(num int) bool {
    if num < 1 {
        return false
    }
    sqrt :=  int(math.Sqrt(float64(num)))

    for i := 2; i <= sqrt; i++ {
        if num % i == 0 {
            return false
        }
    }
    return true
}
//输出质数
func printParam(num int)  {
    fmt.Printf("%d 以内的质数为：",num)
    for i := 2; i < num ; i++ {
        if isParam(i) {
            fmt.Printf("%d ", i)
        }
    }
}

func main() {33     printParam(100)
}

 

二、水仙花数

package main

import (
    "fmt"
    "math"
)
//水仙花数
func printFlower(){
    for i := 100; i < 999; i++ {
        g := i%10 //计算个位
        b := i/100  //计算百位
        s := (i-b*100)/10  //计算十位
        if i == (g*g*g + s*s*s + b*b*b) {
            fmt.Printf("%d is flower number\n", i)
        }
    }
}


func main() {
    fmt.Println("100-1000里面的水仙花数为:")
    printFlower()
}

三、统计字符

package main

import (
    "fmt"
    "math"
)

//统计字符个数
func countChar(str string) {
    var count [256]int
    for i := 0 ;i < len(str); i++ {
        count[str[i]]++
    }
    for i := 0 ;i < 128; i++ {
        fmt.Printf("%c : %d\n",i,count[i])
    }
}
//统计字符个数
func countChar2(str string) {
    var (
        shuzi, zifu, other = 0,0,0
    )

    for i := 0 ;i < len(str); i++ {
        if str[i]>='0' && str[i] <= '9' {
            shuzi++
        } else if str[i]>='a' && str[i] <= 'z'{
            zifu++
        } else if str[i]>='A' && str[i] <= 'Z'{
            zifu++
        } else {
            other++
        }
    }
    fmt.Printf("数字:%d , 字符:%d ,其他:%d\n",shuzi,zifu,other)
}

func main() {
    fmt.Println("统计字符:")
    str := "qwsdjabdhjabwuieda!@#!#!@##$#%^&**(()&(2131321423424DSFSF{}|L:,/.']sdamnbvczxlouey-=1231@!#"
    countChar2(str)
    //countChar(str)
}