Tags: tree dfs tree-traversal

145. Binary Tree Postorder Traversal

Recursive

```cpp class Solution { public: vector ans; void postOrder(TreeNode* root) { if (root == nullptr) return; postOrder(root -> left); postOrder(root -> right); ans.push_back(root -> val); } vector postorderTraversal(TreeNode* root) { postOrder(root); return ans; } }; ``` </details>