Chess probability challenge

Question

Here is my challenge to all .
Try to make a program that will give us the no. of ways to place n queens on a n*n chess board such that no queen threatens the other .
For eg: to place 4 queens on a 4*4 chess board we have only 2 ways
1. 2. 3. 4.
1. q
2. q
3. q
4. q
and other one it's reflection.
Good luck and Happy programming !

Answer 1

The code i put before had a bug...
Have changed it as below in python...
https://code.sololearn.com/c51oMyVHsGkK/#py