void floyd(int rows) {
		for (int k = 0; k < rows; k++)
			for (int i = 0; i < rows; i++)
				for (int j = 0; j < rows; j++)
					if (d[i][j] > d[i][k] + d[k][j]) {
						d[i][j] = d[i][k] + d[k][j];
					}
	}