private void preCalculateHeuristics() {
		heuristics = new double[adjacency.length];
		for (int i = 0; i < heuristics.length; i++) {
			double minimum = Double.MAX_VALUE;
			for (int j = 0; j < adjacency[i].length; j++) {
				if (i != j && adjacency[i][j] >= 0 && adjacency[i][j] < minimum) {
					minimum = adjacency[i][j];
				}
			}
			heuristics[i] = minimum;
		}
	}