added count method

src/Tree.java

@@ -1,2 +1,108 @@
-public class Tree {
+import java.util.ArrayList;
+import java.util.List;
+
+public class Tree<T> {
+  // Private Attributes
+  // The item stored at this tree's root, or null if the tree is empty.
+  private T root;
+
+    }
+  private int count(int item) {
+    if (this.isEmpty()) {
+  // The list of all subtrees of this tree.
+  private List<Tree<T>> subtrees;
+
+  public Tree(T root) {
+    this.root = root;
+    this.subtrees = new ArrayList<>();
+  }
+
+  public Tree(T root, List<Tree<T>> subtrees) {
+    this.root = root;
+    this.subtrees = new ArrayList<>(subtrees);
+  }
+
+  public T getRoot() {
+    return root;
+  }
+
+  public List<Tree<T>> getSubtrees() {
+    return subtrees;
+  }
+
+  public void setRoot(T root) {
+    this.root = root;
+  }
+
+  public void setSubtrees(List<Tree<T>> subtrees) {
+    this.subtrees = subtrees;
+  }
+
+  public boolean is_empty() {
+    return (this.root == null);
+  }
+
+  public int count(int item) {
+    if (this.is_empty()) {
+      return 0;
+    } else {
+      int num = 0;
+      if (this.root.equals(item)) {
+        num += 1;
+      }
+      for (Tree<T> x : this.getSubtrees()) {
+        num += x.count(item);
+      }
+      return num;
+    }
+
+  public double average(){
+    if(this.is_empty()){
+      return 0.0;
+    }
+    count = this.Count();
+    size = this.length();
+    return count / size;
+
+  }
+  private int average_helper(){
+    total = 0;
+    if(this.root){
+      total += 1;
+    }
+    for(Tree i: this.subtrees){
+      total += this.average_helper();
+    }
+    return total;
+  }
+  @Override
+  public boolean equals(Object o) {
+    if (this.is_empty() & o.is_empty()) {
+      return true;
+    } else if (this.is_empty() || other.is_empty()) {
+      return false;
+    } else {
+      if (this.root != other._root) {
+        return false;
+      }
+      if (this.subtrees.length() != other._subtrees.length()) {
+        return false;
+      }
+      return self._subtrees == other._subtrees;
+    }
+  }
+}
+  }
+
+  public int length() {
+    if (this.is_empty()) {
+      return 0;
+    } else {
+      int size = 1;
+      for (Tree<T> x : this.getSubtrees()) {
+        size += x.length();
+      }
+      return size;
+    }
+  }
 }

test/TreeTest.java

@@ -14,4 +14,8 @@ public void dummyTest() {
         assertTrue(true);
     }
 
+    public void TestAverage(){
+        Tree t = new Tree();
+        assertTrue(t.average() == 0.0);
+    }
 }