LeetCode 257 Binary Tree Paths (DFS)

本文主要是介绍LeetCode 257 Binary Tree Paths (DFS)，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

Given a binary tree, return all root-to-leaf paths.

For example, given the following binary tree:

   1/   \
2     3\5

All root-to-leaf paths are:

["1->2->5", "1->3"]

题目分析：DFS即可 （16ms 击败76%）

/*** Definition for a binary tree node.* public class TreeNode {*     int val;*     TreeNode left;*     TreeNode right;*     TreeNode(int x) { val = x; }* }*/
class Solution {public void DFS(TreeNode root, List<String> ans, String cur) {if (root.left == null && root.right == null) {ans.add(cur);return;}if (root.left != null) {DFS(root.left, ans, cur + "->" + root.left.val);} if (root.right != null) {DFS(root.right, ans, cur + "->" + root.right.val);}}public List<String> binaryTreePaths(TreeNode root) {List<String> ans = new ArrayList<>();if (root == null) {return ans;}DFS(root, ans, root.val + "");return ans;}
}

这篇关于LeetCode 257 Binary Tree Paths (DFS)的文章就介绍到这儿，希望我们推荐的文章对编程师们有所帮助！

---