Added methods

src/Traverse.java

@@ -7,8 +7,8 @@ public class Traverse {
   public static void main(String[] args) {
     // See below site for visualization of this graph
     // https://auberonedu.github.io/graph-explore/graph_site/viz.html
-    Vertex<Integer> v3  = new Vertex<>(3);
-    Vertex<Integer> v7  = new Vertex<>(7);
+    Vertex<Integer> v3 = new Vertex<>(3);
+    Vertex<Integer> v7 = new Vertex<>(7);
     Vertex<Integer> v12 = new Vertex<>(12);
     Vertex<Integer> v34 = new Vertex<>(34);
     Vertex<Integer> v56 = new Vertex<>(56);
@@ -18,16 +18,60 @@ public static void main(String[] args) {
     Vertex<Integer> v23 = new Vertex<>(23);
     Vertex<Integer> v67 = new Vertex<>(67);
 
-    v3.neighbors  = new ArrayList<>(List.of(v7, v34));
-    v7.neighbors  = new ArrayList<>(List.of(v12, v45, v34, v56));
+    v3.neighbors = new ArrayList<>(List.of(v7, v34));
+    v7.neighbors = new ArrayList<>(List.of(v12, v45, v34, v56));
     v12.neighbors = new ArrayList<>(List.of(v7, v56, v78));
-    v34.neighbors = new ArrayList<>(List.of(v34, v91)); 
+    v34.neighbors = new ArrayList<>(List.of(v34, v91));
     v56.neighbors = new ArrayList<>(List.of(v78));
     v78.neighbors = new ArrayList<>(List.of(v91));
     v91.neighbors = new ArrayList<>(List.of(v56));
     v45.neighbors = new ArrayList<>(List.of(v23));
     v23.neighbors = new ArrayList<>(List.of());
     v67.neighbors = new ArrayList<>(List.of(v91));
+
+    System.out.println();
+    // Set<Vertex<Integer>> myVisited = new HashSet<>();
+    // traverse(v3);
+    int result = sum(v3);
+    System.out.println(result);
+  }
+
+  public static int sum(Vertex<Integer> current) {
+    Set<Vertex<Integer>> visited = new HashSet<>();
+    return sum(current, visited);
   }
 
+  public static <T> 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>> myVisited = new HashSet<>();
+    traverse(current, myVisited);
+  }
+
+  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);
+    }
+  }
 }