public void detectCol(int n) {
		for (int i = 0; i < 8; i++) {
			for (int j = 0; j < (8 - n + 1); j++) {
				boolean lineOk = true;
				int first = matrix[j][i];
				int k = j;
				while (k < j + n && lineOk) {
					if (matrix[k][i] != first && matrix[k][i] != 0)
						lineOk = false;
					k++;
				}
				if (lineOk) {
					for (k = j; k < (j + n); k++)
						matrixb[k][i] = true;
					j += n + 1;
				}
			}
		}
	}