-
Notifications
You must be signed in to change notification settings - Fork 0
/
257.java
37 lines (32 loc) · 1.08 KB
/
257.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
// https://leetcode.com/problems/binary-tree-paths/
/**
* 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) {
ArrayList<String> result = new ArrayList<>();
if (root == null) return result;
binaryRecursive(root, new StringBuilder(), result);
return result;
}
public void binaryRecursive(TreeNode root, StringBuilder current, List<String> list) {
if (current.length() == 0) {
current.append(root.val);
} else {
current.append("->" + root.val);
}
if (root.left == null && root.right == null && current.toString() != "") {
list.add(current.toString());
}
int oldLength = current.length();
if (root.left != null) binaryRecursive(root.left, current, list);
current.setLength(oldLength);
if (root.right != null) binaryRecursive(root.right, current, list);
}
}