/**
 * Informatik II - FS2009 <br>
 * Uebungsserie 3, Aufgabe 4 <br>
 * Template for LKD.java <br>
 *
 * LKD verifies the syntactical correctness of a binary tree given
 * in left-parenthesis representation <br>
 *
 * @author Philipp Bolliger
 */
public class LKD {

    //the private class field tree contains the
    //left-parenthesis representation of a binary tree
    private char tree[];

    /**
     * Constructor initializes the class field tree.
     *
     * @param tree binary tree in left-parenthesis representation
     */
    public LKD(char[] treeInLKDForm) {
        tree =  treeInLKDForm;
    }

    /**
     * Prints an array of chars and marks the last element with "^"
     * (You can use this method to indicate the element actually causing a syntax error)
     *
     * @param testIndex the index of the last correct element in the tree
     */
    public void invalidPosition( int testIndex ) {
        System.out.println( tree );
        for(int j=0; j < testIndex; j++ ) {
            System.out.print(" ");
        }
        System.out.println("^");
    }

    /**
     * Verifies the syntactical correctness of the left-parenthesis
     * representation of a binary tree
     */
    public void syntaxChecker() {
        int testIndex = 0;

        //ADD YOUR CODE HERE
        //MODIFY THE TEMPLATE IF NECESSARY OR APPROPRIATE!
        //DEFINE AND IMPLEMENT ADEQUATE METHODS TO PERFORM THE SYNTAX CHECK!

        //testIndex = ....

        if( testIndex == tree.length ) {
            //correct left-parenthesis representation
            System.out.println("Valid left-parenthesis representation :-) ");
        }
        else {
            System.out.println( "ERROR: "+
            "Error type 007 detected: ");
            invalidPosition( testIndex );
        }
    }

    public static void main(String[] args) {

        //Parse the input
        if( args.length != 1 ) {
            System.out.println( "Invalid input!");
            System.out.println( "Example of a correct call to LKD.java: " +
            "java LKD \"A(B(C,B(A)))\"" );
            System.exit( 1 );
        }

        //Convert input string to an array of chars (char[]):
        char[] inputLKD = args[0].toCharArray();

        //New instance of the LKD class initialized with the
        //left-parenthesis representation given as input
        LKD check = new LKD(inputLKD);

        //Syntax-checker:
        check.syntaxChecker();
    }
}