java 531. Lonely Pixel I.java

Posted 2021-05-08

public class Solution {
    public int findLonelyPixel(char[][] picture) {
        if (picture == null || picture.length < 1 || picture[0].length < 1) return 0;
        int row = picture.length;
        int col = picture[0].length;
        int[] countR = new int[row];
        int[] countC = new int[col];
        
        for (int i = 0; i < row; i++) {
            for (int j = 0; j < col; j++) {
                if (picture[i][j] == 'B') {
                    countR[i]++;
                    countC[j]++;
                }
            }
        }
        int res = 0;
        for (int i = 0; i < row; i++) {
            for (int j = 0; j < col; j++) {
                if (picture[i][j] == 'B' && countR[i] == 1 && countC[j] == 1) {
                    res++;
                }
            }
        }
        return res;
    }
}