45. N-Queens

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Input: n = 4

Output: [[".Q..","...Q","Q...","..Q."],["..Q.","Q...","...Q",".Q.."]]

Explanation: Two distinct solutions for placing 4 queens on a 4x4 chessboard.

Input: n = 1

Output: [["Q"]]

Explanation: One solution for placing 1 queen on a 1x1 chessboard.

Time Complexity

O(N!)

Space Complexity

O(N)