Now, please write a function called
that returns the number of N Queens solutions for a chessboard of a given size.
For example, if
is 8, then 92 would be returned, because there are 92 possible solutions.
Since we have created
, you would go row by row, and call
to get the columns in the next row to iterate on, and make a recursive call for each of those values.
In the diagram below, there are 4 choices to put another Queen in the next row. Thus, 4 recursive calls would be made where a different one of those choices is added to the existing list of Queens.
When a valid placement of Queens is completed on the last row, a counter should get incremented. At the end, the value of the counter would be returned.