Explore-open-source/BinaryTreeTraversals.java at main · syndax9/Explore-open-source · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
//preorder traversal
 List<Integer> list = new ArrayList<>();
    public List<Integer> preorderTraversal(TreeNode root) {
           if(root==null){
            return list;
        }
        list.add(root.val);
        preorderTraversal(root.left);

        preorderTraversal(root.right);

        return list;
    }

//inorder traversal

 List<Integer> list = new ArrayList<>();
    public List<Integer> inorderTraversal(TreeNode root) {
        if(root==null){
            return list;
        }
        inorderTraversal(root.left);
        list.add(root.val);
        inorderTraversal(root.right);

        return list;
    }


//postorder traversal

     List<Integer> list = new ArrayList<>();
    public List<Integer> postorderTraversal(TreeNode root) {
         if(root==null){
            return list;
        }
        postorderTraversal(root.left);

        postorderTraversal(root.right);
          list.add(root.val);
        return list;
    }