8 Queens Puzzle — Base Camp Math (2024)

8 Queens Puzzle

To win the 8 queens puzzle, you need to find a way to place eight queens on an 8x8 chessboard so that no queen can capture any other queen.

The 8 queens problem is a classic puzzle in chessboard mathematics, where the goal is to place eight queens on a standard 8x8 chessboard in such a way that no queen can capture any other queen. This means that no two queens should be placed on the same row, column, or diagonal. The problem was first posed in the mid-1800s and has since been studied extensively in the fields of mathematics and computer science.

The problem is significant because it is an example of a combinatorial optimization problem, which is a type of problem that requires finding the best solution from a large set of possibilities. It is also a classic problem in the study of algorithms and has been used as a benchmark for testing the efficiency of various algorithms.

Solving the 8 queens problem requires a combination of mathematical reasoning and algorithmic thinking. There are several methods for solving the problem, including backtracking, genetic algorithms, and simulated annealing.

To win the 8 queens puzzle, you need to find a way to place eight queens on an 8x8 chessboard so that no queen can capture any other queen. This means that no two queens can be placed on the same row, column, or diagonal.

One way to solve the problem is to use a backtracking algorithm. This involves placing queens on the board one at a time and checking if the placement is valid. If a queen is placed in a position where it can capture another queen, the algorithm backtracks and tries a different position for the previous queen.

Here are the steps to solve the 8 queens problem using a backtracking algorithm:

  1. Start by placing a queen in the first row of the first column.

  2. Move to the second column and place a queen in the first row of that column.

  3. Continue placing queens in the next columns, starting in the first row and moving downwards.

  4. If you reach a point where you cannot place a queen in any row of a particular column without violating the constraints of the puzzle, backtrack to the previous column and try a different row for the queen in that column.

  5. Repeat steps 3-4 until all eight queens have been placed on the board.

  6. Once you have placed all eight queens on the board, you have solved the puzzle.

Note that there are many different ways to solve the 8 queens problem, and the specific algorithm you use may vary depending on your preferences and experience level.

The objective of the eight queens puzzle is to place eight chess queens on an 8x8 chessboard in a way that no two queens threaten each other. This means that there should not be two queens on the same row, column, or diagonal. This problem is a subset of the more general n queens problem, which involves placing n non-attacking queens on an n×n chessboard. Except for n=2 and n=3, solutions are available for all natural numbers n. Although the exact number of solutions is known only for n ≤ 27, the growth rate of solutions is approximately (0.143 n)n.

The eight queens puzzle was first introduced by chess composer Max Bezzel in 1848. Franz Nauck presented the first solutions to the problem in 1850 and also extended it to the n queens problem. Since then, many mathematicians, including Carl Friedrich Gauss, have contributed to the problem. In 1972, Edsger Dijkstra used this problem as an example of structured programming and presented a detailed description of a depth-first backtracking algorithm.

Finding all the solutions to the 8-queens problem can be computationally intensive, as there are over 4 billion possible arrangements of eight queens on an 8x8 board, but only 92 solutions. There are various ways to reduce computational requirements, such as applying a rule that chooses one queen from each column, which reduces the number of possibilities to 16.8 million. By generating permutations and checking for diagonal attacks, the possibilities can be further reduced to just 40,320.

There are 92 distinct solutions to the eight queens puzzle. However, if solutions that differ only by the symmetry operations of rotation and reflection of the board are counted as one, then there are only 12 fundamental solutions. Each fundamental solution has eight variants obtained by rotating and reflecting it. One of the fundamental solutions has only four variants, and such solutions have only two variants. Hence, the total number of distinct solutions is 92.

8 Queens Puzzle — Base Camp Math (2024)

FAQs

How many solutions to the 8 Queens problem are there? ›

"The eight queens puzzle is the problem of placing eight chess queens on an 8×8 chessboard so that no two queens threaten each other; thus, a solution requires that no two queens share the same row, column, or diagonal. There are 92 solutions.

Which algorithm is used to solve the 8 queens problem? ›

Which algorithm is used to solve 8 queens problem? One common algorithm used to solve the 8 Queens Problem is the backtracking algorithm, which tries to place queens on the chessboard column by column, checking if each placement is valid and backtracking if it is not.

How many solutions are there for 8 queens on 8 * 8 board 91 93 92 90? ›

Explanation: For 8*8 chess board with 8 queens there are total of 92 solutions for the puzzle.

Is 8 queens problem NP-Complete? ›

The problem of putting eight queens on the chess board so as no queen attacks another is a solved problem, as is placing n queens on an nxn board. However if you place some queens on the board and ask for a completion then the problem is NP complete.

What is the logic for the 8 queen problem? ›

The algorithm starts by placing a queen on the first column, then it proceeds to the next column and places a queen in the first safe row of that column. If the algorithm reaches the 8th column and all queens are placed in a safe position, it prints the board and returns true.

How can you solve the puzzle? ›

Jigsaw Puzzle Techniques: Fun & Helpful Ways to Solve a Puzzle
  1. Pick a puzzle. ...
  2. Figure out your puzzle workspace. ...
  3. Sort pieces with puzzle trays or boxes. ...
  4. Solve the edge first or last. ...
  5. Sort by piece shape. ...
  6. Start with smaller sections or solve in quadrants. ...
  7. Take your time and use natural light when possible.
Jan 20, 2023

What is the 8 puzzle problem in AI? ›

Abstract: The 8-puzzle problem is a well-known artificial intelligence problem consisting of a 3x3 grid with 8 tiles numbered 1-8 and one blank space. The goal is to move the tiles around to achieve a specific goal configuration.

Is the 8 queens problem solvable? ›

The eight queens puzzle has 92 distinct solutions. If solutions that differ only by the symmetry operations of rotation and reflection of the board are counted as one, the puzzle has 12 solutions.

What is the objective function in 8 queens problem? ›

The objective function will count the number of queens that are positioned in a place where they cannot be attacked. Given that queens move vertically, it's reasonable to say that no queen should be placed in the same vertical and thus we can represent the position of each queen in a simple array of 8 positions.

What are the implicit constraints for 8 queens problem? ›

No two queens on the same column

This constraint is implicit in the definition of queens . Since no two elements of queens can have the same index, no two queens can be in the same column.

How many solutions exist for the 8 queen problem? ›

How many possible solutions exist for an 8-queen problem? Explanation: For an 8-queen problem, there are 92 possible combinations of optimal solutions.

How to put 8 queens on a chessboard without threatening each other? ›

Placing queens on a chessboard using the knight's move to separate them can be quite a good strategy for playing eight queens. If you remove the black knights from Figure 1a and replace the four white knights with four queens, then no two queens are threatening each other (Figure 1b).

What is the n-queens problem? ›

The N-Queens Problem is a chess puzzle in which N chess queens must be placed on a NxN chessboard so that no two queens threaten each other. It has received extensive research in computer science and mathematics, and it is frequently used as a standard for evaluating algorithms and heuristics.

How many solutions are possible for the N-Queens problem? ›

It has long been known that there are 92 solutions to the problem. Of these 92, there are 12 distinct patterns. All of the 92 solutions can be transformed into one of these 12 unique patterns using rotations and reflections. The 12 basic solutions can be constructed using the following table.

Which technique is commonly used to solve the N-Queens problem? ›

The N-Queens problem may be solved using a variety of methods including backtracking algorithms and mathematical equations such as magic squares. We propose a more efficient approach to the most used technique, backtracking, by removing the threatened cells in order to decrease the number of trial and error steps.

What is the complexity of n queen problem? ›

Hence, the time complexity will be N * (N-1) * (N-2) …. i.e. O(N!) O(N^2), where 'N' is the number of queens. We are using a 2-D array of size N rows and N columns, and also, because of Recursion, the recursive stack will have a linear space here.

Top Articles
Latest Posts
Article information

Author: Laurine Ryan

Last Updated:

Views: 6055

Rating: 4.7 / 5 (77 voted)

Reviews: 92% of readers found this page helpful

Author information

Name: Laurine Ryan

Birthday: 1994-12-23

Address: Suite 751 871 Lissette Throughway, West Kittie, NH 41603

Phone: +2366831109631

Job: Sales Producer

Hobby: Creative writing, Motor sports, Do it yourself, Skateboarding, Coffee roasting, Calligraphy, Stand-up comedy

Introduction: My name is Laurine Ryan, I am a adorable, fair, graceful, spotless, gorgeous, homely, cooperative person who loves writing and wants to share my knowledge and understanding with you.