problem531

README

< Previous 　　　　　　　　　　　　　　　　 Next >

531. Lonely Pixel I (Medium)

Given a picture consisting of black and white pixels, find the number of black lonely pixels.

The picture is represented by a 2D char array consisting of 'B' and 'W', which means black and white pixels respectively.

A black lonely pixel is character 'B' that located at a specific position where the same row and same column don't have any other black pixels.

Example:

Input: 
[['W', 'W', 'B'],
 ['W', 'B', 'W'],
 ['B', 'W', 'W']]
Output: 3
Explanation: All the three 'B's are black lonely pixels.

Note:

1. The range of width and height of the input 2D array is [1,500].

Related Topics

[Depth-first Search] [Array]

Similar Questions

1. Lonely Pixel II (Medium)