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