【LeetCode】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"]

/**
* Definition for a binary tree node.
* struct TreeNode {
*     int val;
*     TreeNode *left;
*     TreeNode *right;
*     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
* };
*/
class Solution {
public:
void getDfsPaths(vector<string>& result, TreeNode* node, string sln)
{
if(!node->left && !node->right)
{
result.push_back(sln);
return;
}
if(node->left)
getDfsPaths(result,node->left, sln+"->"+to_string(node->left->val));
if(node->right)
getDfsPaths(result,node->right, sln+"->"+to_string(node->right->val));
}
vector<string> binaryTreePaths(TreeNode* root) {
vector<string>result;
if(root==NULL) return result;
getDfsPaths(result,root, to_string(root->val));
return result;
}
};