day 1

src/Traverse.java

@@ -3,6 +3,7 @@
 import java.util.List;
 import java.util.Set;
 
+
 public class Traverse {
   public static void main(String[] args) {
     // See below site for visualization of this graph
@@ -28,6 +29,47 @@ public static void main(String[] args) {
     v45.neighbors = new ArrayList<>(List.of(v23));
     v23.neighbors = new ArrayList<>(List.of());
     v67.neighbors = new ArrayList<>(List.of(v91));
+
+    int result = sum(v3);
+    System.out.println(result);
+  }
+
+  public static <T> void traverse(Vertex<T> current){
+    Set<Vertex<T>> myVisited = new HashSet<>();
+    traverse(current, myVisited);
+  }
+
+  public static int sum(Vertex<Integer> current){
+    Set<Vertex<Integer>> visited = new HashSet<>();
+    return sum(current, visited);
+  }
+
+  public static int sum(Vertex<Integer> current, Set<Vertex<Integer>> visited){
+    if (current == null || visited.contains(current)) return 0;
+
+    visited.add(current);
+
+    int total = 0;
+    total += current.data;
+
+    for(Vertex<Integer> neighbor : current.neighbors){
+      int neighborSum = sum(neighbor, visited);
+      total += neighborSum;
+    }
+
+    return total;
+  }
+
+  public static <T> void traverse(Vertex<T> current, Set<Vertex<T>> visited){
+    if(current == null || visited.contains(current)) return;
+
+    System.out.println(current.data);
+    visited.add(current);
+
+    for(Vertex<T> neighbor : current.neighbors){
+      traverse(neighbor, visited);
+    }
+
   }
 
 }