题解 | #挑7#

package main

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

func main() {
	bs := bufio.NewScanner(os.Stdin)
	for bs.Scan() {
		input := bs.Text()
		ret := 0
		inputInt, _ := strconv.Atoi(input)
		for i := 1; i <= inputInt; i++ {
			if i%7 == 0 {
				ret++
			} else {
				str := strconv.Itoa(i)
				loop:for _,stri := range str{
					switch stri {
					case '7' :
						ret++
						break loop
					}
				}
			}
		}
		fmt.Println(ret)
	}
}