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  1. #include <iostream>
  2. #include <memory>
  3. #include <vector>
  4. using namespace std;
  5.  
  6. struct Node {
  7.     int data;
  8.     unique_ptr<Node> left;
  9.     unique_ptr<Node> right;
  10.     Node(int x) : data(x), left(nullptr), right(nullptr) {}
  11. };
  12.  
  13. void insert(unique_ptr<Node>& root, int val) {
  14.     if (!root) {
  15.         root = make_unique<Node>(val);
  16.         return;
  17.     }
  18.     if (root->data == val) {
  19.         return; // Ignore duplicates
  20.     } else if (root->data > val) {
  21.         insert(root->left, val);
  22.     } else {
  23.         insert(root->right, val);
  24.     }
  25. }
  26.  
  27. unique_ptr<Node> buildBST(vector<int>& a) {
  28.     unique_ptr<Node> root = nullptr; // Initialize to nullptr
  29.     for (int i = 0; i < a.size(); i++) {
  30.         insert(root, a[i]);
  31.     }
  32.     return root;
  33. }
  34.  
  35. void inorder(const unique_ptr<Node>& root) {
  36.     if (!root) return; // Base case
  37.     inorder(root->left);
  38.     cout << root->data << " ";
  39.     inorder(root->right);
  40. }
  41.  
  42. void postorder(const unique_ptr<Node>& root) {
  43.     if (!root) return; // Base case
  44.     postorder(root->left);
  45.     postorder(root->right);
  46.     cout << root->data << " ";
  47. }
  48.  
  49. int main() {
  50.     int t;
  51.     cin >> t;
  52.     int testCase = 1; // Track test case number
  53.     while (t--) {
  54.         int n;
  55.         cin >> n;
  56.         vector<int> a(n);
  57.         for (int i = 0; i < n; i++) {
  58.             cin >> a[i];
  59.         }
  60.         auto root = buildBST(a); // Store the BST root
  61.         cout << "Test #" << testCase++ << ": ";
  62.         postorder(root);
  63.         cout << endl; // Add newline for clarity
  64.     }
  65.     return 0;
  66. }
Success #stdin #stdout 0.01s 5316KB
comments (?)
stdin
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3
5
3 1 4 2 5
8
1 6 2 3 8 5 7 4
7
4 7 2 5 3 6 1
stdout
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Test #1: 2 1 5 4 3 
Test #2: 4 5 3 2 7 8 6 1 
Test #3: 1 3 2 6 5 7 4
https://ideone.com/cXdDUC
language:
C++ (gcc 8.3)
created:
1 day ago
visibility:
public

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