Update BSTDictionary.java

src/edu/caltech/cs2/datastructures/BSTDictionary.java

@@ -56,6 +56,32 @@ public class BSTDictionary<K extends Comparable<K>, V> implements IDictionary<K,
     public Iterator<K> iterator() {
         return null;
     }
+    
+    @Override
+    public String toString() {
+        if (this.root == null) {
+            return "{}";
+        }
+
+        StringBuilder contents = new StringBuilder();
+
+        IQueue<BSTNode<K, V>> nodes = new ArrayDeque<>();
+        BSTNode<K, V> current = this.root;
+        while (current != null) {
+            contents.append(current.key + ": " + current.value + ", ");
+
+            if (current.children[0] != null) {
+                nodes.enqueue(current.children[0]);
+            }
+            if (current.children[1] != null) {
+                nodes.enqueue(current.children[1]);
+            }
+
+            current = nodes.dequeue();
+        }
+
+        return "{" + contents.toString().substring(0, contents.length() - 2) + "}";
+    }
 
     protected static class BSTNode<K, V> {
         public final K key;