N-Queen Problem by Backtracking

One of my pressures is already solved

Ok, one of my big pressure, or maybe just my obligation as a student, is already solved. Yeah, as you can see in the title of this post, it's about the task of subject "Algorithm and Programming 2" in my study. Yes, I have to create an algorithm to solve N-Queen problem, and then make a presentation to get highest score in my big quiz.

What is N-Queen problem? As you can see in another search result in search engine, in general, N-Queen problem is how can you get a sollution to set n number of Queen on n x n size of chessboard, where no one can attack each other. In my task, I have to use backtracking algorithm, in order to get the closest sollution, rather than all sollution. It means the output is, there is any sollution or not.

I won't give any source code yet, because when I post this posting, another student maybe still not present it yet. But I will give the algorithm, here it is:

We need 2 arrays to use this algorithm. First is the location of the Queens. We can use 1 dimension array with Integer type to save their coordinates. Why just 1 dimension array? Because we know that just one Queen for one row, so we can save the coordinate like this: queen[y]=x; It means that queen at row y is settled at column x. It will save with less capacity rather than 2 dimension array. The second array has to be 2 dimension array with Boolean type. We use it to save the location where Queens cannot take place based on the coordinate. After one Queen is settled, we change the value of second array, where is the row, column, and all diagonals of the position of the Queen, to be "cannot take place". So in the program's loop, it will be checked and no queens will try that place. So easy, isn't it?

I will give explanation about the variables and methods before the pseudocode. Variable queens means the position of the Queens, variable place means the status of free place (it is initialized with 'true' value), variable y means row, variable x means column, and variable size means board size and the number of Queens. Method isAllSolved() will return whether the problem is already solved or not (true if already solved, false is not solved yet), method createCopyOf(array) will create new array with the same value as the parameter, method setCannotTakePlace(x, y) means set the row, column, and diagonals of [x, y] to be 'false', so no queens can take that place. And method isRowSolved(place, y) return whether the row y is already solved or not (return true if there is any queen, and false if no queen at that row). Here is the pseudocode:
Download here

As I tell before, I won't give any source code yet. But I will give the demo of my program as executable jar file. I use GUI to display the sollution. Once you run the program, an input dialog box will be displayed. You have to type the board size at any size but negative (because the program won't run anything). After that, a window is opened and you will see the first sollution. You can see another sollution by press right/left arrow on your keyboard. I tell you again, it is 'another sollution', not the next sollution. You will see how can it happen after you get the source code soon.

Ok, here is the jar file download link:
Download Here
As usual, I set the password at my file:
fauzilhaqqi.blogspot.com

Ok, I hope you will enjoy waiting the source code. If you can't wait any longer, please be free to contact me at my email, fauzil.haqqi@gmail.com. I will send to you privately as you give your contact too. One more thing, I use Java SE to create the program.