题解 | #合法IP#

import java.util.*;

public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
while (sc.hasNext()) {
String str = sc.nextLine();
System.out.println(checkIp(str));
}
}
public static String checkIp(String str){
String[] strArray = str.split("\.");
if (strArray.length != 4) {
return "NO";
}
for (String e : strArray) {
try {
if (!e.equals("0") && e.startsWith("0")) {
return "NO";
}
int num = Integer.parseInt(e);
if (num > 255 || num < 0) {
return "NO";
}
} catch (Exception e1) {
return "NO";
}
}
return "YES";
}
}