257. Binary Tree Paths

257. Binary Tree Paths

Given a binary tree, return all root-to-leaf paths.

For example, given the following binary tree:



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:
vector<string> binaryTreePaths(TreeNode* root) {
vector<string> result;
if(root==NULL)
return result;
string path;
getPath(result,path,root);
return result;
}
void getPath(vector<string>& vec,string& path,TreeNode* node)
{
path+=to_string(node->val);
if(node->left==NULL&&node->right==NULL)
vec.push_back(path);
if(node->left!=NULL)
{
string path1=path+"->";
getPath(vec,path1,node->left);
}
if(node->right!=NULL)
{
string path2=path+"->";
getPath(vec,path2,node->right);
}
}
};