TileDifference Class Reference

Implementation of the tile difference heuristic for the 8-puzzle. More...

#include <Heuristic.hpp>

Inheritance diagram for TileDifference:

Collaboration diagram for TileDifference:

Public Member Functions
int	calc (GameState &currentState)
	Calculates the heuristic value for a state. More...

Detailed Description

Implementation of the tile difference heuristic for the 8-puzzle.

Definition at line 43 of file Heuristic.hpp.

Member Function Documentation

calc()

int TileDifference::calc ( GameState &  currentState )

inlinevirtual

Calculates the heuristic value for a state.

Parameters

currentState

the state to be evaluated

Returns

heuristic value for currentState

Implements Heuristic.

Definition at line 46 of file Heuristic.hpp.

                                    {
    int distance = 0, dimension = currentState.getDimension();

    // adds 1 for every tile that is not in its goal position
    for (int i = 0; i < pow(dimension, 2); i ++) {
      int *pos = currentState.find(i);
      int x = pos[0], y = pos[1];
      delete[] pos;
      int x_opt = i != 0 ? (i - 1) / dimension : 2,
          y_opt = i != 0 ? (i - 1) % dimension : 2;

      distance += x != x_opt || y != y_opt;
    }
    return distance;
  }

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The documentation for this class was generated from the following file:

• include/Heuristic.hpp