Implement a recursive solution for placing N queens on the chessboard so that no two queens attack each other using Backtracking. Give the number of solutions for placing n queens on an n n board, for n=1 to 20. Construct the state space tree for a 6 X 6 chessboard and give the number of promising and non-promising nodes.Give the python code for this question. Also mention best, worse and average case time complexity and space complexity.