/**
 * Informatik II - FS2009 <br>
 * Uebungsserie 2, Aufgabe 3 <br>
 * Template for ConvertTree.java <br>
 *
 * @author Philipp Bolliger
 */
public class ConvertTree {

    char[] tree; //tree is a reference to an array of char

    /**
     * Initializes the class field 'tree' with the given char array.
     *
     * @param treeAsCharArray array representation of a binary tree
     **/
    ConvertTree(char[] treeAsCharArray) {
        tree = treeAsCharArray;
    }

    /**
     * Outputs the "indented" representation of the tree stored in the class field 'tree'.
     *
     * @param i position in array
     * @param j current indentation-level
     **/
    void indent( int i, int j ) {

        if( true /* insert break condition here!! */ ) return;

        //Print a space for each new tree-level
        for( int n=0; n<j; n++ ) {
            System.out.print( " " );
        }

        //Print the current node
        System.out.println(tree[i]);

        //recursive call: traverse left subtree
        indent( 2*i ,j+1);
        //recursive call: traverse right subtree
        //....
    }

    /**
     * Input the tree's array-representation as a
     * single string argument.
     * If your representation includes space characters,
     * then include quotes.
     * Example:
     *
     * java CovertTree $"123  67"$
     *
     * Test the program with the following inputs (an empty subtree
     * is represented with a space character):
     *
     * "1234567"
     * "1 3  67"
     * "AB D   H       P"
     * "A C   G       O"
     **/
    public static void main( String[] args ) {

        if( args.length == 0 ||  args.length > 1 ) {
            System.out.println( "Invalid input" );
            System.exit( 1 );
        }

        // Prefix the input-string with a space character, so that
        // the effective tree starts at index 1 (why is this "needed"?)
        String input = " " + args[0];

        //Create an instance of the class ConvertTree using the "new" keyword.
        //The class field 'tree' is initialized with the tree array
        //representation given as input parameter. The method toCharArray
        //converts the input string in an array of characters.
        ConvertTree ct = new ConvertTree(input.toCharArray());

        //The 'indent' method is called on the ct instance of the ConvertTree class.
        ct.indent(1,0);
    }
}