Breadth First Search

Hi folks

I'm trying to develop a breadth first search method but having some problems. I'm trying to add a string (MI) as the lone member of a queue, and expand on that string using my nextStates( that string ) method if it doesnt match a pre-determined string (b) defined in the main. Below is my code, so far it doesn't return anything even though b is a next state of MI. Was wondering if anyone could point out why this is and a possible fix. Any help would be appreciated. Thanks

Code:

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        public static boolean breadthFirstSearch (String b)
        {
                boolean flag = false;
                Queue<String> qe=new LinkedList<String>();        //sets up queue
                qe.add("MI");                                                                //adds MI to queue
                while(flag = false)                                               
                {
                        qe.addAll(nextStates(qe.element()));        //add all the nextStates of b to the queue 

                        if(qe.poll()== b)
                        {
                                flag = true;
                                System.out.println("found!");        //found the state therefore
                        }
                }


                return true;   
        }

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Your comparison of "qe.poll()== b" is incorrect - you cannot compare two string like that.
Use e.g. "qe.poll().equals(b)" for that purpose or the case insensitive equivalent.

Quote:

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while(flag = false){ }

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boolean flag=true;
...
while(flag) or while(flag==true)

Quote:

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Originally Posted by kosmos890

boolean flag=true;
...
while(flag)

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Good.

Quote:

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Originally Posted by kosmos890

or while(flag==true)

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Bad. If you support comparing a boolean variable with a boolean literal for equivalence, why stop there? Why not

Code:

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while ((((flag == true) == true) == true) == true) {

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db

@DarrylBurke
Thanks. It was my mistake!