Flood fill Algorithm Java

PROGRAM TO IMPLEMENT FLOOD FILL ALGORITHM




class MAIN

{

 

// Dimentions of paint screen

static int M = 8;

static int N = 8;

 

// A recursive function to replace previous color 'prevC' at '(x, y)'

// and all surrounding pixels of (x, y) with new color 'newC' and

static void floodFillUtil(int screen[][], int x, int y,

                                    int prevC, int newC)

{

    // Base cases

    if (x < 0 || x >= M || y < 0 || y >= N)

        return;

    if (screen[x][y] != prevC)

        return;

 

    // Replace the color at (x, y)

    screen[x][y] = newC;

 

    // Recur for north, east, south and west

    floodFillUtil(screen, x+1, y, prevC, newC);

    floodFillUtil(screen, x-1, y, prevC, newC);

    floodFillUtil(screen, x, y+1, prevC, newC);

    floodFillUtil(screen, x, y-1, prevC, newC);

}

 

// It mainly finds the previous color on (x, y) and

// calls floodFillUtil()

static void floodFill(int screen[][], int x, int y, int newC)

{

    int prevC = screen[x][y];

    floodFillUtil(screen, x, y, prevC, newC);

}

 

// Driver code

public static void main(String[] args)

{

    int screen[][] = {{1, 1, 1, 1, 1, 1, 1, 1},

                    {1, 1, 1, 1, 1, 1, 0, 0},

                    {1, 0, 0, 1, 1, 0, 1, 1},

                    {1, 2, 2, 2, 2, 0, 1, 0},

                    {1, 1, 1, 2, 2, 0, 1, 0},

                    {1, 1, 1, 2, 2, 2, 2, 0},

                    {1, 1, 1, 1, 1, 2, 1, 1},

                    {1, 1, 1, 1, 1, 2, 2, 1},

                    };

    int x = 4, y = 4, newC = 3;

    floodFill(screen, x, y, newC);

 

    System.out.println("Updated screen after call to floodFill: ");

    for (int i = 0; i < M; i++)

    {

        for (int j = 0; j < N; j++)

        System.out.print(screen[i][j] + " ");

        System.out.println();

    }

    }

}




OUTPUT

Updated screen after call to floodFill: 
1 1 1 1 1 1 1 1 
1 1 1 1 1 1 0 0 
1 0 0 1 1 0 1 1 
1 3 3 3 3 0 1 0 
1 1 1 3 3 0 1 0 
1 1 1 3 3 3 3 0 
1 1 1 1 1 3 1 1 
1 1 1 1 1 3 3 1 

CREDITS: https://www.geeksforgeeks.org/flood-fill-algorithm-implement-fill-paint/