Algo#16: Solve 8-Queen Problem.

8-Queen problem ask us to set 8 queen on board such that they don't attack each other by any direction. We must be knowing that queen can move row wise, column wise and in both diagonals also.

First thing we need here is, way to check whether we can put chosen queen at particular location or not. We can put queen only if satisfy following criteria.
1. It should be unique in its row.
2. It should be unique in its column.
3. It should be unique in its both diagonals.

Lets say we made some function called Check() which tell whether current queen have any conflicts with previous queens that we have set. Now we are ready to take up our back tracking algorithm.

Following is simple algorithm for finding 8-Queen Problem.

Step 1: If we have filled all rows of board than we are done.
Step 2: Otherwise try all possible columns for current queen and check if it has any conflicts with any previous queen, if not then set remaining queens.

Following is implementation of above algorithm in c language.

Please write comments if you find anything wrong or you want to add something more related to this topic.