// @Title: 二叉树的所有路径 (Binary Tree Paths)
// @Author: qisiii
// @Date: 2024-09-15 16:48:02
// @Runtime: 2 ms
// @Memory: 41.4 MB
// @comment: 
// @flag: 
/**
 * Definition for a binary tree node.
 * public class TreeNode {
 * int val;
 * TreeNode left;
 * TreeNode right;
 * TreeNode() {}
 * TreeNode(int val) { this.val = val; }
 * TreeNode(int val, TreeNode left, TreeNode right) {
 * this.val = val;
 * this.left = left;
 * this.right = right;
 * }
 * }
 */
class Solution {
    public List<String> binaryTreePaths(TreeNode root) {
        List<String> result = new ArrayList<>();
        doSolutin(root, result, "");
        return result;
    }

    private void doSolutin(TreeNode node, List<String> result, String str) {
        if (node == null) {
            return;
        }
        str = str  + String.valueOf(node.val) ;
        if (node.left == null && node.right == null) {
            result.add(str);
            return;
        }
        str=str+"->";
        doSolutin(node.left, result, str);
        doSolutin(node.right, result, str);
    }
}