/**
 * Definition of TreeNode:
 * public class TreeNode {
 *     public int val;
 *     public TreeNode left, right;
 *     public TreeNode(int val) {
 *         this.val = val;
 *         this.left = this.right = null;
 *     }
 * }
 */
public class Solution {
    /**
     * @param root the root of the binary tree
     * @return all root-to-leaf paths
     */
    List<String> paths= new ArrayList<>();
    public List<String> binaryTreePaths(TreeNode root) {
        // Write your code here
        if (root==null){
            return null;

        }
        else if (root.left==null && root.right==null) {
            System.out.print(root.val);
            paths.add(Integer.toString(root.val));
        }

        else if (root.left!=null && root.right!=null){
            System.out.print(root.val+"->");
            paths.addAll(binaryTreePaths(root.left));
            paths.addAll(binaryTreePaths(root.right));
        }
        else if (root.left==null && root.right!=null){
            System.out.print(root.val+"->");
            paths.addAll(binaryTreePaths(root.right));
        }

        else if (root.left!=null && root.right==null){
            System.out.print(root.val+"->");
            paths.addAll(binaryTreePaths(root.left));
        }


        /*
        else if (root.left!=null ){
            System.out.print(root.val+"->");
            paths.addAll(binaryTreePaths(root.left));
            if (root.right!=null){
                paths.addAll(binaryTreePaths(root.right));

            }

        }
        else if (root.right!=null){
            System.out.print(root.val+"->");
            paths.addAll(binaryTreePaths(root.right));
            if (root.left!=null ){
                paths.addAll(binaryTreePaths(root.left));
            }

        }
        */


        return paths;

    }
}