首页 > itarticle > leetcode-733

leetcode-733

admin 11月 13, 2020 0

问题描述

n 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.
1
2
3
4
5
6
7
8
9
10
11
>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].

解题思路

深度优先搜索，如果[sr,sc]满足条件，则将其周围的点中满足条件的点进行递归计算

解题代码

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