Python 3.14 (Coding): N-Queens Solution Test

The solution approach of "N-Queens" problem is using backtracking. The goal is to find all distinct solutions for placing "N" queens on an "N x N" chessboard without any queen threatening another. The solution utilizes a depth-first search approach to explore possible configurations efficiently.

The function solveNQueens takes an integer n as input and returns a vector of vectors of strings representing the solutions. The backtrack function is used to perform the actual exploration.

In the backtrack function, the algorithm iterates through each column in the current row r. It checks whether placing a queen at the current position is valid, considering the constraints of not sharing the same column or diagonals with other queens. If the position is valid, the queen is placed, and the corresponding flags are updated to mark the occupied columns and diagonals.

The recursion continues to the next row, and the process repeats. When all queens are placed successfully, a valid solution is found and added to the result vector.

If a solution isn't possible in the current configuration, the algorithm backtracks by resetting the board, column, and diagonal flags to their previous state, allowing the algorithm to explore other possibilities.

The solveNQueens function returns a vector containing all solutions, where each solution is represented by a vector of strings, indicating the queen positions on the board.