# Binary Tree Paths Problem

## Description

LeetCode Problem 257.

Given the root of a binary tree, return all root-to-leaf paths in any order.

A leaf is a node with no children.

Example 1:

``````1
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Input: root = [1,2,3,null,5]
Output: ["1->2->5","1->3"]
``````

Example 2:

``````1
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Input: root = [1]
Output: ["1"]
``````

Constraints:

• The number of nodes in the tree is in the range [1, 100].
• -100 <= Node.val <= 100

## Sample C++ Code

``````1
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class Solution {
public:
void dfs(TreeNode* root, vector<string> &result, string s) {
if (root->left == NULL && root->right == NULL) {
result.push_back(s);
return;
}
if (root->left)
dfs(root->left, result, s + "->" + to_string(root->left->val));
if (root->right)
dfs(root->right, result, s + "->" + to_string(root->right->val));
return;
}
vector<string> binaryTreePaths(TreeNode* root) {
vector<string> result;
if (root == NULL)
return result;
dfs(root, result, to_string(root->val));
return result;
}
};
``````