题解 | #统计字符#

package main

import (
	"bufio"
	"fmt"
	"os"
	"unicode"
)

func main() {
    reader := bufio.NewReader(os.Stdin)
    res,_,_ := reader.ReadLine()
    m, s, n, o := 0, 0,0,0
    for _, ch := range res {
        if ch = byte(unicode.ToLower(rune(ch))); ch >= 'a' && ch <= 'z' {
            m++
        } else if  ch >= '0' && ch <= '9' {
            n++
        } else if ch == ' ' {
            s++
        } else {
            o++
        }
    }
    fmt.Printf("%d\n%d\n%d\n%d\n", m, s, n, o)
}