private static final String digits= "0123456789abcdef";
static int toNumber(String s, int radix) {
int num= 0;
for (int i= 0, n= s.length(); i < n; i++)
num= num*radix+digits.indexOf(s.charAt(i));
return num;
}
static String toString(int num, int radix) {
StringBuilder sb= new StringBuilder();
for(; num != 0; num/= radix)
sb.insert(0, digits.charAt(num%radix));
return sb.length() == 0?"0":sb.toString();
} |