LeetCode 733. Flood Fill

An image is represented by a 2-D array of integers, each integer representing the pixel value of the image (from 0 to 65535).

Given a coordinate (sr, sc) representing the starting pixel (row and column) of the flood fill, and a pixel value newColor, “flood fill” the image.

To perform a “flood fill”, consider the starting pixel, plus any pixels connected 4-directionally to the starting pixel of the same color as the starting pixel, plus any pixels connected 4-directionally to those pixels (also with the same color as the starting pixel), and so on. Replace the color of all of the aforementioned pixels with the newColor.

At the end, return the modified image.

Example 1:

Input: 
image = [[1,1,1],[1,1,0],[1,0,1]]
sr = 1, sc = 1, newColor = 2
Output: [[2,2,2],[2,2,0],[2,0,1]]
Explanation: 
From the center of the image (with position (sr, sc) = (1, 1)), all pixels connected 
by a path of the same color as the starting pixel are colored with the new color.
Note the bottom corner is not colored 2, because it is not 4-directionally connected
to the starting pixel.

Note:

The length of image and image[0] will be in the range [1, 50].
The given starting pixel will satisfy 0 <= sr < image.length and 0 <= sc < image[0].length.
The value of each color in image[i][j] and newColor will be an integer in [0, 65535].

給定一個位置的值，將與其相鄰的所有位置都變成和它相同的值.
最基本的深度搜尋，遞迴，只是這型別題做的比較少了

遞迴之後程式碼也是很簡潔了

public int[][] floodFill(int[][] image, int sr, int sc, int newColor) {
        if(image[sr][sc] != newColor) {
            floodFill(image, sr, sc, image[sr][sc], newColor);
        }
        return image;
    }
    public void floodFill(int[][] image, int sr, int sc, int oldcolor, int newColor) {
        if(sr < 0 || sc <0 || sr >= image.length || sr >= image[0].length || image[sr][sc] != oldcolor) return;
        image[sr][sc] = newColor;
        floodFill(image, sr + 1, sc, oldcolor, newColor);
        floodFill(image, sr - 1, sc, oldcolor, newColor);
        floodFill(image, sr , sc+1, oldcolor, newColor);
        floodFill(image, sr, sc - 1, oldcolor, newColor);
    }