题解 | 合法IP

package main

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

func main() {
    bs := bufio.NewScanner(os.Stdin)
    for bs.Scan() {
        s := bs.Text()
        ip := net.ParseIP(s)
        if ip != nil {
            fmt.Println("YES")
        } else {
            fmt.Println("NO")
        }
    }
}