import java.util.regex.Matcher;
import java.util.regex.Pattern;


public class Mini {

    public static void main(String[] args) {
        int a = 0;
        int b = 0;
        int c = 0;

    String formula = " -x^2 + 6x - 5";
    formula = formula.replaceAll(" ", "");

    if (!formula.startsWith("+") && !formula.startsWith("-"))
        formula = "+" + formula;

        String exp = "^((.*)x\\^2)?((.*)x)?([\\+\\s\\-\\d]*)?$";
        Pattern p = Pattern.compile(exp);
        Matcher m = p.matcher(formula);

        System.out.println("Formula is " + formula);
        System.out.println("Pattern is " + m.pattern());

        while (m.find()) {
            a = getDigit(m.group(2));
            b = getDigit(m.group(4));
            c = getDigit(m.group(5));
        }

        System.out.println("a: " + a + " b: " + b + " c: " + c);

    }

    private static int getDigit(String data) {
        if (data == null) {
            return 0;
        } 
        else 
        {

            if (data.equals("+"))
            {
                return 1;
            }
            else if (data.equals("-"))
            {
                return -1;
            }
            else
            {
                try
                {
                    int num = (int) Float.parseFloat(data);
                    return num;
                }
                catch (NumberFormatException ex)
                {
                    return 0;
                }
            }
        }
    }
}