Почему не !pattern.matcher(line).find(), а pattern.matcher(line).find()?
package com.javarush.task.task30.task3010;
import java.util.regex.Pattern;
/*
Минимальное допустимое основание системы счисления
*/
public class Solution {
public static void main(String[] args) {
String line = null;
try {
line = args[0];
Pattern pattern = Pattern.compile("[^0-9A-Za-z]");
if (!pattern.matcher(line).find()) {
System.out.println("incorrect");
} else {
char max = 0;
char[] chars = line.toUpperCase().toCharArray();
for (char current : chars) {
if (current > max) {
max = current;
}
}
int radix;
if (max <= '9') {
radix = max - 47;
} else {
radix = max - 54;
}
if (radix < 2) {
radix = 2;
}
System.out.println(radix);
}
} catch (Exception e) {
}
}
}