Example: java flood fill
// Java program to implement flood fill algorithm
class GFG
{
// 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);
}
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();
}
}
}