Flood Fill

In computer graphics, an uncompressed raster image is presented as a matrix of numbers. Each entry of the matrix represents the color of a pixel. A flood fill algorithm takes a coordinate r, c and a replacement color, and replaces all pixels connected to r, c that have the same color (i.e., the pixels connected to the given coordinate with of same color and all the other pixels connected to the those pixels of the same color) with the replacement color. (e.g. MS-Paint's paint bucket tool).

Input

• r: row
• c: column
• replacement: replacement color
• image: an 2D array of integers representing the image

Output

the replaced image

Examples

Example 1:

Input:

1r = 2
2c = 2
3replacement = 9
4arr = [[0,1,3,4,1],[3,8,8,3,3],[6,7,8,8,3],[12,2,8,9,1],[12,3,1,3,2]]

Output: [[0,1,3,4,1],[3,9,9,3,3],[6,7,9,9,3],[12,2,9,9,1],[12,3,1,3,2]]

Explanation:

From

10 1 3 4 1
23 8 8 3 3
36 7 8 8 3
412 2 8 9 1
512 3 1 3 2

to

10 1 3 4 1
23 9 9 3 3
36 7 9 9 3
412 2 9 9 1
512 3 1 3 2

Try it yourself

Solution