Linked List Basics

One correct implementation. Alternative approaches that satisfy the constraints are equally valid — the reviewer judges behaviour, not style.

#include <bits/stdc++.h>
using namespace std;

struct Node {
  int val;
  Node* next;
  Node(int v) : val(v), next(nullptr) {}
};

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);

  int n; cin >> n;
  Node* head = nullptr;
  Node* tail = nullptr;
  for (int i = 0; i < n; i++) {
    int x; cin >> x;
    Node* node = new Node(x);
    if (!head) { head = tail = node; }
    else { tail->next = node; tail = node; }
  }
  int x; cin >> x; // insert at head
  Node* h = new Node(x);
  h->next = head; head = h;
  for (Node* cur = head; cur; cur = cur->next) {
    if (cur != head) cout << ' ';
    cout << cur->val;
  }
  cout << '\n';
  return 0;
}