1 files changed, 100 insertions, 0 deletions
diff --git a/BJC-Utils2/src/main/java/bjc/utils/graph/AdjacencyMap.java b/BJC-Utils2/src/main/java/bjc/utils/graph/AdjacencyMap.java
new file mode 100644
index 0000000..7a79233
--- /dev/null
+++ b/BJC-Utils2/src/main/java/bjc/utils/graph/AdjacencyMap.java
@@ -0,0 +1,100 @@
+package bjc.utils.graph;
+
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.io.PrintStream;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Scanner;
+import java.util.Set;
+import java.util.stream.IntStream;
+
+public class AdjacencyMap<T> {
+	private Map<T, Map<T, Integer>> adjMap;
+
+	public AdjacencyMap(Set<T> vertices) {
+		vertices.forEach(src -> {
+			Map<T, Integer> srcRow = new HashMap<>();
+
+			vertices.forEach(tgt -> srcRow.put(tgt, 0));
+
+			adjMap.put(src, srcRow);
+		});
+	}
+
+	public boolean isDirected() {
+		GenHolder<Boolean> res = new GenHolder<>(true);
+
+		adjMap.entrySet()
+				.forEach(src -> src.getValue().entrySet().forEach(tgt -> {
+					int lhs = tgt.getValue();
+					int rhs = adjMap.get(tgt.getKey()).get(src.getKey());
+
+					if (lhs != rhs) {
+						res.held = false;
+					}
+				}));
+
+		return res.held;
+	}
+
+	public void setWeight(T src, T tgt, int weight) {
+		adjMap.get(src).put(tgt, weight);
+	}
+
+	public Graph<T> toGraph() {
+		Graph<T> ret = new Graph<>();
+
+		adjMap.entrySet()
+				.forEach(src -> src.getValue().entrySet()
+						.forEach(tgt -> ret.addEdge(src.getKey(),
+								tgt.getKey(), tgt.getValue())));
+
+		return ret;
+	}
+
+	public static AdjacencyMap<Integer> fromStream(InputStream stream) {
+		Scanner scn = new Scanner(stream);
+		scn.useDelimiter("\n");
+
+		// First, read in number of vertices
+		int numVertices = Integer.parseInt(scn.next());
+
+		Set<Integer> vertices = new HashSet<>();
+		IntStream.range(0, numVertices).forEach(e -> vertices.add(e));
+
+		// Create the adjacency map
+		AdjacencyMap<Integer> aMap = new AdjacencyMap<>(vertices);
+
+		GenHolder<Integer> row = new GenHolder<>(0);
+
+		scn.forEachRemaining((strang) -> {
+			String[] parts = strang.split(" ");
+			int col = 0;
+
+			for (String part : parts) {
+				aMap.setWeight(row.held, col, Integer.parseInt(part));
+
+				col++;
+			}
+
+			row.held++;
+		});
+
+		scn.close();
+
+		return aMap;
+	}
+
+	public void toStream(OutputStream os) {
+		PrintStream ps = new PrintStream(os);
+
+		adjMap.entrySet().forEach(src -> {
+			src.getValue().entrySet()
+					.forEach(tgt -> ps.printf("%d ", tgt.getValue()));
+			ps.println();
+		});
+		ps.close();
+	}
+}