-
Notifications
You must be signed in to change notification settings - Fork 12.9k
/
BinaryTreePaths.java
49 lines (39 loc) · 1.08 KB
/
BinaryTreePaths.java
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
// 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 BinaryTreePaths {
public List<String> binaryTreePaths(TreeNode root) {
List<String> result = new ArrayList<String>();
if(root == null) {
return result;
}
helper(new String(), root, result);
return result;
}
public void helper(String current, TreeNode root, List<String> result) {
if(root.left == null && root.right == null) {
result.add(current + root.val);
}
if(root.left != null) {
helper(current + root.val + "->", root.left, result);
}
if(root.right != null) {
helper(current + root.val + "->", root.right, result);
}
}
}