package com.thealgorithms.dynamicprogramming;
/**
* Java program for Boundary fill algorithm.
* @author Akshay Dubey (https://github.com/itsAkshayDubey)
*/
public final class BoundaryFill {
private BoundaryFill() {
}
/**
* Get the color at the given co-odrinates of a 2D image
*
* @param image The image to be filled
* @param xCoordinate The x co-ordinate of which color is to be obtained
* @param yCoordinate The y co-ordinate of which color is to be obtained
*/
public static int getPixel(int[][] image, int xCoordinate, int yCoordinate) {
return image[xCoordinate][yCoordinate];
}
/**
* Put the color at the given co-odrinates of a 2D image
*
* @param image The image to be filed
* @param xCoordinate The x co-ordinate at which color is to be filled
* @param yCoordinate The y co-ordinate at which color is to be filled
*/
public static void putPixel(int[][] image, int xCoordinate, int yCoordinate, int newColor) {
image[xCoordinate][yCoordinate] = newColor;
}
/**
* Fill the 2D image with new color
*
* @param image The image to be filed
* @param xCoordinate The x co-ordinate at which color is to be filled
* @param yCoordinate The y co-ordinate at which color is to be filled
* @param newColor The new color which to be filled in the image
* @param boundaryColor The old color which is to be replaced in the image
*/
public static void boundaryFill(int[][] image, int xCoordinate, int yCoordinate, int newColor, int boundaryColor) {
if (xCoordinate >= 0 && yCoordinate >= 0 && getPixel(image, xCoordinate, yCoordinate) != newColor && getPixel(image, xCoordinate, yCoordinate) != boundaryColor) {
putPixel(image, xCoordinate, yCoordinate, newColor);
boundaryFill(image, xCoordinate + 1, yCoordinate, newColor, boundaryColor);
boundaryFill(image, xCoordinate - 1, yCoordinate, newColor, boundaryColor);
boundaryFill(image, xCoordinate, yCoordinate + 1, newColor, boundaryColor);
boundaryFill(image, xCoordinate, yCoordinate - 1, newColor, boundaryColor);
boundaryFill(image, xCoordinate + 1, yCoordinate - 1, newColor, boundaryColor);
boundaryFill(image, xCoordinate - 1, yCoordinate + 1, newColor, boundaryColor);
boundaryFill(image, xCoordinate + 1, yCoordinate + 1, newColor, boundaryColor);
boundaryFill(image, xCoordinate - 1, yCoordinate - 1, newColor, boundaryColor);
}
}
/**
* This method will print the 2D image matrix
*
* @param image The image to be printed on the console
*/
public static void printImageArray(int[][] image) {
for (int i = 0; i < image.length; i++) {
for (int j = 0; j < image[0].length; j++) {
System.out.print(image[i][j] + " ");
}
System.out.println();
}
}
// Driver Program
public static void main(String[] args) {
// Input 2D image matrix
int[][] image = {
{0, 0, 0, 0, 0, 0, 0},
{0, 3, 3, 3, 3, 0, 0},
{0, 3, 0, 0, 3, 0, 0},
{0, 3, 0, 0, 3, 3, 3},
{0, 3, 3, 3, 0, 0, 3},
{0, 0, 0, 3, 0, 0, 3},
{0, 0, 0, 3, 3, 3, 3},
};
boundaryFill(image, 2, 2, 5, 3);
/* Output ==>
* 0 0 0 0 0 0 0
0 3 3 3 3 0 0
0 3 5 5 3 0 0
0 3 5 5 3 3 3
0 3 3 3 5 5 3
0 0 0 3 5 5 3
0 0 0 3 3 3 3
* */
// print 2D image matrix
printImageArray(image);
}
}