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"]
/**
* Definition for a binary tree node.
* public class TreeNode {
* int val;
* TreeNode left;
* TreeNode right;
* TreeNode(int x) { val = x; }
* }
*/
public class Solution {
List<String> result = new LinkedList<>();
List<Integer> path = new LinkedList<>();
public List<String> binaryTreePaths(TreeNode root) {
if(root ==null) return result;
getPaths(root);
return result;
}
public void getPaths(TreeNode node){
if(node == null) return;
path.add(node.val);
if(node.left == null && node.right == null){
StringBuffer buffer = new StringBuffer();
for(int i=0;i<path.size();i++){
if(i!=0)
buffer.append("->");
buffer.append(path.get(i));
}
result.add(buffer.toString());
}
getPaths(node.left);
getPaths(node.right);
path.remove(path.size()-1);
}
}