Add Flood Fill Algorithm Implementation (#2821)

Co-authored-by: Andrii Siriak <[email protected]>

Author: itsAkshayDubey

src/main/java/com/thealgorithms/dynamicprogramming/FloodFill.java

@@ -0,0 +1,114 @@
+package com.thealgorithms.dynamicprogramming;
+
+/**
+ * Java program for Flood fill algorithm.
+ * @author Akshay Dubey (https://github.com/itsAkshayDubey)
+ */
+public class FloodFill {
+
+    /**
+     * Get the color at the given co-odrinates of a 2D image
+     *
+     * @param image The image to be filled
+     * @param x_co_ordinate The x co-ordinate of which color is to be obtained
+     * @param y_co_ordinate The y co-ordinate of which color is to be obtained
+     */
+	
+	public static int getPixel(int[][] image, int x_co_ordinate, int y_co_ordinate) {
+	
+		return image[x_co_ordinate][y_co_ordinate];
+	
+	}
+	
+    /**
+     * Put the color at the given co-odrinates of a 2D image
+     *
+     * @param image The image to be filed
+     * @param x_co_ordinate The x co-ordinate at which color is to be filled
+     * @param y_co_ordinate The y co-ordinate at which color is to be filled
+     */
+	public static void putPixel(int[][] image, int x_co_ordinate, int y_co_ordinate, int new_color) {
+		
+		image[x_co_ordinate][y_co_ordinate] = new_color;
+	
+	}
+	
+	
+    /**
+     * Fill the 2D image with new color
+     *
+     * @param image The image to be filed
+     * @param x_co_ordinate The x co-ordinate at which color is to be filled
+     * @param y_co_ordinate The y co-ordinate at which color is to be filled
+     * @param new_color The new color which to be filled in the image
+     * @param old_color The old color which is to be replaced in the image
+     * @return
+     */
+	public static void floodFill(int[][] image, int x_co_ordinate, int y_co_ordinate, int new_color, int old_color) {
+		if(x_co_ordinate >= 0 && y_co_ordinate >= 0 && getPixel(image, x_co_ordinate, y_co_ordinate) == old_color) {
+			
+			putPixel(image, x_co_ordinate, y_co_ordinate, new_color);
+			floodFill(image, x_co_ordinate + 1, y_co_ordinate, new_color, old_color);
+			floodFill(image, x_co_ordinate - 1, y_co_ordinate, new_color, old_color);
+			floodFill(image, x_co_ordinate, y_co_ordinate + 1, new_color, old_color);
+			floodFill(image, x_co_ordinate, y_co_ordinate - 1, new_color, old_color);
+			floodFill(image, x_co_ordinate + 1, y_co_ordinate - 1, new_color, old_color);
+			floodFill(image, x_co_ordinate - 1, y_co_ordinate + 1, new_color, old_color);
+			floodFill(image, x_co_ordinate + 1, y_co_ordinate + 1, new_color, old_color);
+			floodFill(image, x_co_ordinate - 1, y_co_ordinate - 1, new_color, old_color);
+			
+			
+		}
+		
+	}
+	
+    /**
+     * 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},
+				{0,3,1,1,5,0,0},
+				{0,3,1,1,5,5,3},
+				{0,3,5,5,1,1,3},
+				{0,0,0,5,1,1,3},
+				{0,0,0,3,3,3,3}
+		};
+		
+		floodFill(image,2,2,2,1);
+
+		/* Output ==>
+		 * 0  0  0  0  0  0  0  
+		   0  3  3  3  3  0  0  
+		   0  3  2  2  5  0  0  
+           0  3  2  2  5  5  3  
+           0  3  5  5  2  2  3  
+           0  0  0  5  2  2  3  
+           0  0  0  3  3  3  3
+		 * */
+		
+		//print 2D image matrix
+		printImageArray(image);
+	}
+
+}