Doing homework, implementation of the algorithm flood fills. I'm writing a program to this guide: http://en.wikipedia.org/wiki/Flood_fill. And I have some questions:
- Is it normal to specify the parameters in function replaces the color of any character
bucketFill.fill (0, 0, '*', 'O');, I do not know what kind of color will be initially to these coordinates? An algorithm is correct? I wrote it for example in Wikipedia, but the result of my program is as follows:
@@@@@ @@@@@ @@@@@ @@@@@ @@@@@ @@@@@ @@@@@I think must be this:
*@@@@ @@@@@ @@#@@ @@@@@ @@@@@ @@@## @@@@@
My code:
class BucketFill {
private char[][] pixels;
public BucketFill(char[][] pixels) {
this.pixels = pixels;
}
public void fill(int x, int y, char newColor, char oldColor) {
if (x < 0) return;
if (y < 0) return;
if (x >= pixels.length) return;
if (y >= pixels[x].length) return;
oldColor = pixels[x][y];
if (newColor == pixels[x][y]) return;
if (oldColor != pixels[x][y]) return;
pixels[x][y] = newColor;
fill(x - 1, y, newColor, oldColor);
fill(x + 1, y, newColor, oldColor);
fill(x, y - 1, newColor, oldColor);
fill(x, y + 1, newColor, oldColor);
}
public void inspect() {
for (int y = 0; y < pixels.length; y++) {
for (int x = 0; x < pixels[y].length; x++) {
System.out.print(pixels[y][x]);
}
System.out.print("\n");
}
}
public static void main(String argv[]) {
char pixels[][] =
{
{ 'O', 'X', 'X', 'X', 'X' },
{ 'X', 'O', 'O', 'O', 'X' },
{ 'X', 'O', '#', 'O', 'X' },
{ 'X', 'O', 'O', 'O', 'X' },
{ 'X', 'X', 'X', 'X', 'X' },
{ 'X', 'X', 'X', '#', '#' },
{ 'X', 'X', 'X', 'X', 'X' }
};
BucketFill bucketFill = new BucketFill(pixels);
bucketFill.fill(0, 0, '*', 'O');
bucketFill.fill(3, 0, 'O', 'O');
bucketFill.fill(2, 1, '@', 'O');
bucketFill.inspect();
}
}
