题解 | #统计字符#

package main

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

func calculateLetter(s string) {
    var letterCnt, blankCnt, digitCnt, otherCnt int

    for i:=0; i<len(s); i++ {
        if ('A' <= s[i] && s[i] <= 'Z') || ('a' <= s[i] && s[i] <= 'z') {
            letterCnt++
        } else if s[i] == ' ' {
            blankCnt++
        } else if '0' <= s[i] && s[i] <= '9' {
            digitCnt++
        } else {
            otherCnt++
        }
    }

    fmt.Printf("%d\n%d\n%d\n%d", letterCnt, blankCnt, digitCnt, otherCnt)
}

func main() {
    var s string

    inputReader := bufio.NewReader(os.Stdin)
    line, _, _ := inputReader.ReadLine()

    s = string(line)
    calculateLetter(s)
}

// 本题输入为一行字符串，包含空格，所以采用：inputReader.ReadLine()