进制转换

Scanner sc = new Scanner(System.in);
            System.out.println("请输入一个数字");
            int x = sc.nextInt();
            System.out.println("请输入当前数字的进制(n>2)");
            int m = sc.nextInt();
            System.out.println("请输入要转换的数字的进制(n<36)");
            int n = sc.nextInt();
            sc.close();
            String s1 = String.valueOf(x);
            //将该数字转换成十进制的数值
            int q = 0;
            for(int i = s1.length() - 1,j = 0;i >= 0;i --,j ++){
                q += Math.pow(m, j) * (Integer.valueOf((char)s1.charAt(i) - 48));
            }
            System.out.println("该数值当前的进制是"+m+"  该数字转换成十进制的数值为"+q);
            System.out.println("接下来我们转换成"+n+"进制!");
            List<Integer> remainderArray = new ArrayList<Integer>();
            while(q >= n){
                remainderArray.add(q % n);
                q /= n;
            }
            remainderArray.add(q % n);
            //拼接
            StringBuilder sb = new StringBuilder();
            for(int i = remainderArray.size() - 1;i >= 0;i --){
                sb.append(remainderArray.get(i));
            }
            System.out.println(sb);