N ary tree postorder traversal

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81.0% acceptance

Jan 13, 2026

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Given the root of an n-ary tree, return the postorder traversal of its nodes' values.

Solution

C++

Time O(n)

Space O(1)

LeetCode

solution.cpp

class Solution {
public:
  vector<int> postorder(Node* root) {
    if (!root) return {};
    vector<int> result;
    for (Node* child : root->children) {
      auto sub = postorder(child);
      result.insert(result.end(), sub.begin(), sub.end());
    }
    result.push_back(root->val);
    return result;
  }
};