题解 | #进制转换#java实现

import java.util.Scanner;
public class Main{
    public static void main(String[] args){
        Scanner in = new Scanner(System.in);
        while (in.hasNextLine()) {
            String original = in.nextLine().substring(2);
            int value = 0;
            //计算每一位值，并加起来
            for(int i = 0; i < original.length(); i++){
                value += getValue(original.charAt(i), original.length() - i -1);
            }
            System.out.println(value);
        }

    }
    //根据字符对应的ASCII码，将16进制字符转为10进制int值
    //b为该字符对应多少个16的乘积
     public static int getValue(char a, int b){
         int num = 0;
         if((int)a >= 65){//A-F
             num = (int)a - 55;
         } else {//0-9
             num = (int)a - 48;
         }
         while(b > 0){
             num *= 16;
             b--;
         }
         return num;
        }
}