1 files changed, 38 insertions, 0 deletions

diff --git a/src/uk/ac/ox/cs/pagoda/util/data_structures/Graph.java b/src/uk/ac/ox/cs/pagoda/util/data_structures/Graph.java
new file mode 100644
index 0000000..4f454df
--- /dev/null
+++ b/src/uk/ac/ox/cs/pagoda/util/data_structures/Graph.java
@@ -0,0 +1,38 @@
+package uk.ac.ox.cs.pagoda.util.data_structures;
+
+import java.util.*;
+
+public class Graph<V> {
+
+    private final boolean isDirected;
+
+    private Map<V, Set<V>> outEdgesOf = new HashMap<>();
+    public Graph(boolean isDirected) {
+        this.isDirected = isDirected;
+    }
+
+    public Graph() {
+        this(false);
+    }
+    public void addNode(V v) {
+        if(!outEdgesOf.containsKey(v))
+            outEdgesOf.put(v, new HashSet<V>());
+    }
+
+    public void addEdge(V v, V u) {
+        addNode(v);
+        addNode(u);
+        outEdgesOf.get(v).add(u);
+
+        if(isDirected)
+            outEdgesOf.get(u).add(v);
+    }
+
+    public Iterator<V> getOutNeighbors(V v) {
+        return outEdgesOf.get(v).iterator();
+    }
+
+    public boolean isDirected() {
+        return isDirected;
+    }
+}