题解 | #合法IP#

package main

import (
	"fmt"
	"io"
	"strings"
	"strconv"
)

func main() {
	for {
		var (
			s string
		)
		_, err := fmt.Scan(&s)
		if err == io.EOF {
			return
		}
		ips := strings.Split(s, ".")
		if len(ips) != 4 {
			fmt.Println("NO")
			return
		}
		var flag bool
		for i := range ips {
			num, _ := strconv.Atoi(ips[i])
			if num < 0 || num > 255 {
				flag = true
				break
			}
		}
		if !flag {
			fmt.Println("YES")
		} else {
			fmt.Println("NO")
		}
	}
}