Description:
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 {
public List<String> paths;
public List<Integer> path;
public List<String> binaryTreePaths(TreeNode root) {
paths = new ArrayList<String>();
path = new ArrayList<Integer>();
getAllPath(root); return paths;
} public void getAllPath(TreeNode node) { // 1
// / \
// 2 3 ["1->2->5", "1->3"]
// \
// if(node == null) {
return ;
}
path.add(node.val);
if(node.left==null && node.right==null) {
StringBuilder onePath = new StringBuilder();
for(int i=0; i<path.size(); i++) {
if(i != 0) onePath.append("->");
onePath.append(path.get(i));
}
paths.add(onePath.toString());
}
getAllPath(node.left);
getAllPath(node.right);
path.remove(path.size() - 1); }
}