# Verbose Java solution without HashMap. 19ms beat 95%.

• ``````public class Solution {
public int findBlackPixel(char[][] picture, int N) {
if (picture.length == 0 || picture[0].length == 0) return 0;
int m = picture.length;
int n = picture[0].length;
int[] I = new int[m];
int[] J = new int[n];
for (int i = 0; i < m; i++) {
int count = 0;
for (int j = 0; j < n; j++) {
if (picture[i][j] == 'B') {
count++;
}
}
I[i] = count;
}
for (int j = 0; j < n; j++) {
int count = 0;
for (int i = 0; i < m; i++) {
if (picture[i][j] == 'B') {
count++;
}
}
J[j] = count;
}
int ret = 0;
for (int j = 0; j < n; j++) {
if (J[j] != N) {
continue;
}
int count = 0;
boolean flag = true;
String prev = null;
for (int i = 0; i < m; i++) {
if (picture[i][j] == 'B' && I[i] == N) {
String cur = new String(picture[i]);
if (prev == null) {
prev = cur;
} else if (!prev.equals(cur)) {
flag = false;
break;
}
count++;
} else if (picture[i][j] == 'B') {
flag = false;
break;
}
}
if (flag) {
ret += count;
}
}
return ret;
}
}
``````

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