/**
* Description of calculate(Puzzle puzzle). This method finds conflicting numbers which are they
* own row or column but reversed order. Every conflict adds +2 to counter. Why? Every conflict
* needs two extra movements to solution. Manhattan Distance value is added to Linear Conflict
* value at before it is returned.
*
* @return amount of conflicts * 2 + Manhattan Distance
*/
@Override
public int calculate(Puzzle puzzle) {
this.puzzle = puzzle;
rows = puzzle.getNumberOfRows();
columns = puzzle.getNumberOfColumns();
int lc = 0;
for (int row = 0; row < rows; row++) {
lc += calHorizontal(row);
}
for (int col = 0; col < columns; col++) {
lc += calVertical(col);
}
return lc + md.calculate(puzzle);
}
/**
* Description of calHorizontal(int row). This method returns linear conflicts in certain column.
*
* @param row row which conflicts are checked
* @return amount of conflicts * 2
*/
private int calHorizontal(int row) {
int lc = 0;
int max = -1;
for (int col = 0; col < columns; col++) {
int num = puzzle.getNumberInCell(row, col);
if (num != puzzle.getEmpty() && num / rows == row) {
if (num > max) {
max = num;
} else {
lc += 2;
}
}
}
return lc;
}
/**
* Description of calVertical(int col). This method returns linear conflicts in certain row.
*
* @param col column which conflict are checked
* @return amount of conflicts * 2
*/
private int calVertical(int col) {
int lc = 0;
int max = -1;
for (int row = 0; row < rows; row++) {
int num = puzzle.getNumberInCell(row, col);
if (num != puzzle.getEmpty() && num % columns == col) {
if (num > max) {
max = num;
} else {
lc += 2;
}
}
}
return lc;
}
/**
* Description of update(int h, int dRow, int dCol). This method calculates change in Manhattan
* distance and Linear Conflict.
*
* <p>THIS METHOD IS TOO LONG IN CLEAN CODE SENSE. FOR EFFICIENCY REASONS I HAVE NOT SPLIT IT.
* SORRY!!!
*
* @param dRow change in row
* @param dCol change in col
* @return change in estimation value compared previous situation
*/
@Override
public int update(int h, int dRow, int dCol) {
int now = 0;
int old = 0;
if (dCol == 0) {
int numOwnRow = puzzle.lastMove / 4;
if (puzzle.getEmptyRow() == numOwnRow) {
now = calHorizontal(numOwnRow);
puzzle.setCell(numOwnRow, puzzle.getEmptyCol(), puzzle.getLastMove());
old = calHorizontal(numOwnRow);
puzzle.setCell(numOwnRow, puzzle.getEmptyCol(), puzzle.getEmpty());
} else {
if (puzzle.getEmptyRow() - dRow == numOwnRow) {
now = calHorizontal(numOwnRow);
puzzle.setCell(numOwnRow, puzzle.getEmptyCol(), puzzle.getEmpty());
old = calHorizontal(numOwnRow);
puzzle.setCell(numOwnRow, puzzle.getEmptyCol(), puzzle.getLastMove());
}
}
} else {
int numOwnCol = puzzle.lastMove % 4;
if (puzzle.getEmptyCol() == numOwnCol) {
now = calVertical(numOwnCol);
puzzle.setCell(puzzle.getEmptyRow(), numOwnCol, puzzle.getLastMove());
old = calVertical(numOwnCol);
puzzle.setCell(puzzle.getEmptyRow(), numOwnCol, puzzle.getEmpty());
} else {
if (puzzle.getEmptyCol() - dCol == numOwnCol) {
now = calVertical(numOwnCol);
puzzle.setCell(puzzle.getEmptyRow(), numOwnCol, puzzle.getEmpty());
old = calVertical(numOwnCol);
puzzle.setCell(puzzle.getEmptyRow(), numOwnCol, puzzle.getLastMove());
}
}
}
return h + md.update(0, dRow, dCol) + now - old;
}