checkparenstest.java

Java程序设计技巧与开发实例附书源代码。

public class CheckParensTest
{
    public static boolean checkParens(String exp)
    {
        Stack s = new Stack();
        for (int i = 0; i < exp.length(); i++)
        {
            char cc = exp.charAt(i);
            if (Parenthesis.isOpening(cc))
            {
                s.push(new Parenthesis(cc));
            }
            if (Parenthesis.isClosing(cc))
            {
                try
                {
                    Parenthesis parens = (Parenthesis) s.pop();
                    if (!parens.matches(cc))
                    {
                        return false;
                    }
                }
                catch (StackException se)
                {
                    return false;
                }
            }
        }
        return s.isEmpty();
    }

    public static void main(String args[])
    {
        System.out.print("Enter string: ");
        String string = Console.readString();
        System.out.println("checkParens: " + checkParens(string));
    }
}