题解 | #进制转换#

import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner Scanner = new Scanner(System.in);
        while(Scanner.hasNextLine()){
            String hexString = Scanner.nextLine().trim();

            //排除可能的十六进制前缀“0x”和“0X”
            if(hexString.startsWith("0x") || hexString.startsWith("0X")){
                hexString = hexString.substring(2);
            }
            try{
                //将十六进制转化为十进制
                long decimalValue = Long.parseLong(hexString ,16);
                System.out.println(decimalValue);
            }catch(NumberFormatException e){
                System.out.println("invalid decimalValue number");
            }
        }
        Scanner.close();
    }
}