Solution: N-Queens
Explore the backtracking approach to solve the classic N-Queens puzzle by placing queens on an n×n chessboard without conflicts. Learn to use helper arrays for tracking columns and diagonals, implement recursive placement, and backtrack to find all valid arrangements. This lesson helps you practice a foundational coding interview pattern involving recursion and constraint checking to prepare for technical interviews.
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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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