## 题目描述：

LeetCode 531. Lonely Pixel I

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].

## Python代码：

``````class Solution(object):
def findLonelyPixel(self, picture):
"""
:type picture: List[List[str]]
:rtype: int
"""
w, h = len(picture), len(picture)
rows, cols =  * w,  * h
for x in range(w):
for y in range(h):
if picture[x][y] == 'B':
rows[x] += 1
cols[y] += 1
ans = 0
for x in range(w):
for y in range(h):
if picture[x][y] == 'B':
if rows[x] == 1:
if cols[y] == 1:
ans += 1
return ans
``````

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