Question

I am not asking for the solution. I want all the possible placements.

Answer 1

The below code is in C#. Hope it helps

    static void Main(string[] args)
    {
        Program obj = new Program();
        StreamWriter saveText = new StreamWriter("Output.txt",true);
        obj.fourQueen(0, 0, 4, "");
        Console.Read();

    }


    public void fourQueen(int r , int c, int queensLeft, string onePlacement){
        if(queensLeft == 0){
            //onePlacement may not be a answer
            Console.WriteLine(onePlacement);
        return ;

        }

        if(c==4){
            //If I have reached the end of 1 row, go to next one
            c=0;
            r=r+1;
        }
        if(r==4){
            //I have considered all rows and still not put all queens. cannot be a solution
            return;
        }
        int te = queensLeft - 1;






        int newcol = c + 1;
        fourQueen(r,newcol,te,onePlacement+"| ("+r+","+c+")|");
        //Note: As i am placing queen in (r,c) above, there is no point in continuing //recursive call from r,c+1 as cannot place another in same row. I should
        //go from  r+1,0
        fourQueen(r,newcol,queensLeft,onePlacement);


    }
}

}