void floyd() {
			int rows = d.length;
			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];
						}
		}