# What is meant by 8-puzzle problem?

## What is meant by 8-puzzle problem?

The 8-puzzle problem is a puzzle invented and popularized by Noyes Palmer Chapman in the 1870s. It is played on a 3-by-3 grid with 8 square blocks labeled 1 through 8 and a blank square. Your goal is to rearrange the blocks so that they are in order.

Which algorithm is used in 8-puzzle problem?

A* Algorithm is one of the best and popular techniques used for path finding and graph traversals.

How do you solve the 8th puzzle with best first search?

Best-first search. First, insert the initial state (the initial board, 0 moves, and a null previous state) into a priority queue. Then, delete from the priority queue the state with the minimum priority, and insert onto the priority queue all neighboring states (those that can be reached in one move).

### What is the heuristic for 8-puzzle problem?

h4 = 5 (out of row) + 8 (out of column) = 13. optimal solution to this problem as a heuristic for the 8-puzzle. Represent the ‘space’ as a tile and assume you can swap any two tiles. Use the cost of the optimal solution to this problem as a heuristic for the 8-puzzle.

What is goal state in 8-puzzle?

Two possible states of the 8-puzzle are shown in figure 1. The state on the right is a typical goal state. The state on the left is a configuration that represents a worst case: transforming this state into the goal state requires at least 31 actions, which is the diameter of the search space.

What are the states in 8-puzzle problem?

The classical 8-puzzle belongs to the family of sliding blocks. My book (Artificial intelligence A modern approach by Stuart Russell and peter Norwig) says that the 8-puzzle has 9!/2 possible states.

#### How do you solve the 8-puzzle problem in artificial intelligence?

Solution: The puzzle can be solved by moving the tiles one by one in the single empty space and thus achieving the Goal state. Instead of moving the tiles in the empty space we can visualize moving the empty space in place of the tile. The empty space cannot move diagonally and can take only one step at a time.

What is Manhattan distance in 8-puzzle problem?

A good heuristic for the 8-puzzle is the number of tiles out of place. A better heuristic is the sum of the distances of each tile from its goal position (“Manhattan distance”). An even better heuristic takes into account the number of direct adjacent tile reversals present.

How many states does 8-puzzle have?

The classical 8-puzzle belongs to the family of sliding blocks. My book (Artificial intelligence A modern approach by Stuart Russell and Peter Norwig) says that the 8-puzzle has 9!/2 possible states.

## What are the state space for 8-puzzle problem?

The 8-puzzle consists of a 3×3 board with eight numbered tiles and a blank space. A tile adjacent to the blank space can slide into the space. The object is to reach a specified goal state. States: A state specifies the location of each of the eight tiles and the blank in one of the nine squares.

What is an 8 puzzle?

An 8 puzzle is a simple game consisting of a 3 x 3 grid (containing 9 squares). One of the squares is empty. The object is to move to squares around into different positions and having the numbers displayed in the “goal state”.

What is the a* search algorithm?

A* search is a computer search algorithm that is widely used for pathfinding and graph traversal. In our case of the 8 puzzle problem, we will be using it for optimal graph traversal. A* works by keeping track of all visited nodes and ignoring them for further traversal.

### Which heuristic search algorithm is used for the 8 puzzle?

There are many different types of heuristic search algorithms. One of them is the A* search algorithm. A* search is a computer search algorithm that is widely used for pathfinding and graph traversal. In our case of the 8 puzzle problem, we will be using it for optimal graph traversal.

Which pathfinding algorithm should I use to solve the puzzle?

Download the 8 Puzzle Unlimited App from Google Play. Typically A* (Astar) is used in a grid-based pathfinding problem. However, as a general rule, any pathfinding algorithm (A* included) can be used to solve any graph-based problem.