CellsAdjacency.java

//  Sokoban state space explorer.
//  Discussion: https://dxdy.ru/topic144781.html

import java.util.*;

public class CellsAdjacency {

    private int totalCellsNumber, activeCellsNumber;
    /*
        Array "values" consists of consecutive records for every possible transition
        from cell to cell. Records for moves from same cell are placed one after another,
        comprising blocks. Array "indices" holds starting indices of said same starting
        cell blocks and contain one more index to denote arrays "values" size for convenience.
        Values record:
        -   direction index (from CellVector class)
        -   adjacent cell index
        -   next adjacent cell index
        -   rear adjacent cell index
        Impassable and inactive next adjacent cells are assigned -1 index. Rear adjacent cells
        are assigned -1 index if it is impassable or starting cell is inactive.
    //*/
    private short [] values;
    private int   [] indices;

    public CellsAdjacency (int totalCellsNumber, int activeCellsNumber, short [] values, int [] indices) {
        this .totalCellsNumber  = totalCellsNumber;
        this .activeCellsNumber = activeCellsNumber;
        this .values            = values;
        this .indices           = indices;
    }

    public int getTotalCellsNumber () {
        return totalCellsNumber;
    }

    public int getActiveCellsNumber () {
        return activeCellsNumber;
    }

    public short [] getValues () {
        return Arrays .copyOf (values,  values  .length);
    }

    public int [] getIndices () {
        return Arrays .copyOf (indices, indices .length);
    }
}