N-Queens
A Classic Backtracking Problem
-
Algorithms and Data Structures: TheAlgorist.com
-
System Design: DistributedComputing.dev
-
Low Level Design: LowLevelDesign.io
-
Frontend Engineering: FrontendEngineering.io
Problem Statement:
The n-queens puzzle is the problem of placing n queens on an n x n chessboard such that no two queens attack each other. Two queen can attack each other when they share the same row, column, or diagonal.
One of the many valid configurations for 8-Queens problem:
Given an integer n, return all distinct solutions to the n-queens puzzle.
Each solution contains a distinct board configuration of the n-queens' placement, where 'Q' and '.' both indicate a queen and an empty space, respectively.
Example 1:
Input: n = 4
Output: [[".Q..","...Q","Q...","..Q."],["..Q.","Q...","...Q",".Q.."]]
Example 2:
Input: n = 1
Output: [["Q"]]
Solution:
- NOTE: I highly recommend going through the Backtracking chapters in the order they are given in the Index page to get the most out of it and be able to build a rock-solid understanding.
Prerequisite: Backtracking Fundamentals
Detailed Algorithm Discussion:
This is a Premium content.
Please subscribe to the Algorithms course to access the detailed Algorithm discussion.
Java Code:
This is a Premium content.
Please subscribe to Algorithms course to access the code.
Python Code:
This is a Premium content.
Please subscribe to Algorithms course to access the code.
Time Complexity:
Please subscribe to access the complexity analysis.
Don't forget to take in-depth look at the other backtracking problems because that is what would make you comfortable with using the backtracking template and master the art of Backtracking:
- Letter Case Permutation
- Power Set
- All Paths Between Two Nodes
- Word Search
- Sudoku
- Word Square
- Generate Parentheses
Instructor:
If you have any feedback, please use this form: https://thealgorists.com/Feedback.
