N Queens

Problem

Return all valid board arrangements for n queens, in deterministic row-by-row order.

Examples

Example 1

Input: 4

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

Example 2

Input: 1

Output: [["Q"]]

Input and output use JSON-compatible values. For linked-list and tree questions, arrays represent the node structure as described above. Your code should implement solve(input).

Write your solutionImplement solve(input). Your draft is saved in this browser.

Compiler

How to solve N Queens

Return all valid board arrangements for n queens, in deterministic row-by-row order. Track columns and both diagonal families occupied by previous queens. The reference implementation illustrates this approach; check the example and edge cases.

Time and space complexity

Backtracking has exponential worst-case time.

Practise and improve

Choose JavaScript, TypeScript or Python, complete the starter code, then select Run Tests. Request a hint when you need guidance, or choose View solution and confirm if you would like to study the reference implementation.