OperatorList

import java.util.Vector;

class Operator {
    public char data;
    public int precedence;
    public boolean left_assoc;

    public Operator( char operator , int num , boolean assoc ) {
        data = operator;
        precedence = num;
        left_assoc = assoc;
    }
}
public class OperatorList {
    public static Vector<Operator> list = new Vector<Operator>();

    public static void initList() {
        list.add( new Operator( '=' , 4 , false ) );
        list.add( new Operator( '+' , 3 , true ) );
        list.add( new Operator( '-' , 3 , true ) );
        list.add( new Operator( '*' , 2 , true ) );
        list.add( new Operator( '/' , 2 , true ) );
        list.add( new Operator( '!' , 1 , false ) );
    }

    public static boolean isOperator( char c ) {
        for(int i = 0; i < list.size(); i++ ) {
            if( list.elementAt( i ).data == c ) {
                return true;
            }
        }
        return false;
    }

    public static int getOperatorPrecedence( char c ) {
        for( int i = 0; i < list.size(); i++ ) {
            if( list.elementAt( i ).data == c ) {
                return list.elementAt( i ).precedence;
            }
        }
        return -1;
    }

    public static boolean stronger( char act , char topstack  ) {
        if( getOperatorPrecedence( act ) > getOperatorPrecedence( topstack ) ) {
            return true;
        }
        else {
            return false;
        }
    }

    public static void main( String[] args ) {
        initList();
        System.out.println( PostFix.convertInFixToPostFix("a+b*c-d") );
    }
}