题解HJ5 | #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 in = new Scanner(System.in);
        // 注意 hasNext 和 hasNextLine 的区别
        String s = in.nextLine();

        int result = 0;
        for (int i = 2; i < s.length(); i++) {
            char a = s.charAt(i);

            if (a >= '0' && a <= '9') {
                result += (a - '0') * (Math.pow(16, s.length() - i - 1));
            } else if (a >= 'a' && a <= 'g') {
                result += (a - 'a' + 10) * (Math.pow(16, s.length() - i - 1));
            } else if (a >= 'A' && a <= 'G') {
                result += (a - 'A' + 10) * (Math.pow(16, s.length() - i - 1));
            }
        }

        System.out.println(result);
    }
}