LeetCode@DFS_257_Binary_Tree_Paths

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"]

java:

/**
* 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> path = new LinkedList<>();
Stack<TreeNode> node = new Stack<>();
Stack<String> subPath = new Stack<>();

if(root == null)
{
return path;
}
node.push(root);
subPath.push("");
while (!node.isEmpty())
{
TreeNode currNode = node.pop();
String curr = subPath.pop();
//stack.pop();
if (currNode.left != null)
{
subPath.push(curr+currNode.val+"->");
node.push(currNode.left);
}
if (currNode.right != null)
{
subPath.push(curr+currNode.val+"->");
node.push(currNode.right);
}
if (currNode.left == null && currNode.right == null)
{
path.add(curr+currNode.val);
}
}
return path;

}

}