Solution: N-Queens
Explore the backtracking algorithm to solve the classic N-Queens puzzle by placing n queens on an n×n chessboard where no two queens attack each other. Understand how to track columns and diagonals for safety checks, implement recursive backtracking, and generate all valid board arrangements. Master the tradeoffs in time and space complexity for this classic coding interview challenge.
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Statement
The N-Queens puzzle is a classic problem in which the goal is to place n queens on an n n chessboard so that no two queens can attack each other.
In chess, a queen can move any number of squares horizontally, vertically, or diagonally. Therefore, no two queens can be placed in the same row, column, or diagonal.
Given an integer n, return all distinct valid arrangements of n queens on the board. Each arrangement should be represented as a list of strings, where each string corresponds to a row of the board. Within each string, 'Q' denotes a queen and '.' denotes an empty square.
Note: You can return the solutions in any order.
Constraints:
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