766. Flood Fill Algorithm

You are given an m x n integer grid image representing a picture, along with three integers: sr, sc, and color. Starting from the pixel at (sr, sc), flood-fill the image: change the color of (sr, sc) and every 4-directionally connected pixel of the same original color to the given color. Return the modified image. Input is a JSON object with fields image, sr, sc, and color. If the starting pixel's color already equals color, return the image unchanged.

Input: A JSON object: {"image":[[...]],"sr":r,"sc":c,"color":v}.

Output: Return the modified grid as a JSON 2D array.

Examples

Input: {"image":[[1,1,1],[1,1,0],[1,0,1]],"sr":1,"sc":1,"color":2}
Output: [[2,2,2],[2,2,0],[2,0,1]]
Explanation: All connected 1s reachable from (1,1) become 2.

Input: {"image":[[0,0,0],[0,0,0]],"sr":0,"sc":0,"color":2}
Output: [[2,2,2],[2,2,2]]
Explanation: Entire grid is connected 0s.

Input: {"image":[[1,1],[1,1]],"sr":0,"sc":0,"color":1}
Output: [[1,1],[1,1]]
Explanation: Already that color; no change.

Constraints

• 1 <= m, n <= 5
• 0 <= image[i][j] <= 9
• 0 <= sr < m, 0 <= sc < n
• 0 <= color <= 9

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