十进制与任意进制互转

	//n进制转十进制
    static int transfer(char[] chars, int n){
        int result = 0;
        int index = chars.length - 1;
        
        while (index >= 0){
            result += (chars[index] - '0') * Math.pow(n, chars.length - 1 - index);
            index -= 1;
        }
        
        return result;
    }


    //十进制转n进制
    static StringBuilder transferToN(long num, int n){
        StringBuilder result = new StringBuilder();

        //求n进制的位数
        int i = 0;
        long m = (long) Math.pow(n,i);
        long k = num / m;
        while (k > 0){
            m = (long) Math.pow(n,++i);
            k = num / m;
        }

        //从高位到低位依次填充值
        for (int j = i - 1; j >= 0; j--) {
            long v1 = (long) Math.pow(n, j);
            //当前位上的值
            long v =  (num / v1);
            result.append(v);
            num = (num % v1);
        }

        return result;
    }