Binary Tree Paths

题目链接：https://leetcode.com/submissions/detail/37771540/

题目：

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"]

题意：找出给定二叉树中的所有路径

分析：遍历每个节点，记录其路径（如果当前节点有子节点，则调用递归继续遍历其子节点，并记录新路径，删除之前路径）

代码：

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

Binary Tree Paths

原文：http://blog.csdn.net/yangyao_iphone/article/details/48028729