733. Flood Fill

T :O(mn)

S: O(2m+2n)

```java
class Solution {
    private static final int[][] DIRS = {{0,1}, {1, 0}, {-1, 0}, {0, -1}};
    public int[][] floodFill(int[][] image, int sr, int sc, int color) {
        int m = image.length;
        int n = image[0].length;
        
        int initColor = image[sr][sc];
        Queue<int[]> queue = new LinkedList<>();
        queue.offer(new int[]{sr, sc});

        while (!queue.isEmpty()) {
            int[] cur = queue.poll();
            if (image[cur[0]][cur[1]] == color) {
                continue;
            }
            image[cur[0]][cur[1]] = color;

            for (int[] dir : DIRS) {
                int x = cur[0] + dir[0];
                int y = cur[1] + dir[1];
                if (x < 0 || x >= m || y < 0 || y >= n || image[x][y] != initColor) {
                    continue;
                }
                queue.offer(new int[]{x, y});
            }
        }
        return image;
    }
}
```