Problem p02977 (C++)

Buggy submission (status: Runtime Error):
#include <bits/stdc++.h>
#pragma GCC optimize("O2,unroll-loops")
// #pragma GCC optimize("no-stack-protector,fast-math")
// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")

using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<pii, int> piii;
typedef pair<ll, ll> pll;
#define debug(x) cerr << #x << '=' << (x) << endl;
#define debugp(x)                                                              \
  cerr << #x << "= {" << (x.first) << ", " << (x.second) << "}" << endl;
#define debug2(x, y)                                                           \
  cerr << "{" << #x << ", " << #y << "} = {" << (x) << ", " << (y) << "}"      \
       << endl;
#define debugv(v)                                                              \
  {                                                                            \
    cerr << #v << " : ";                                                       \
    for (auto x : v)                                                           \
      cerr << x << ' ';                                                        \
    cerr << endl;                                                              \
  }
#define all(x) x.begin(), x.end()
#define pb push_back
#define kill(x) return cout << x << '\n', 0;

const ld eps = 1e-7;
const int inf = 1000000010;
const ll INF = 10000000000000010LL;
const int mod = 1000000007;
const int MAXN = 100010, LOG = 20;

int n, m, k, u, v, x, y, t, a, b, ans;
int A[MAXN];

int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  // freopen("input.txt", "r", stdin);
  // freopen("output.txt", "w", stdout);
  cin >> n;
  if ((n & -n) == n)
    kill("No") cout << "Yes\n";
  cout << 1 << ' ' << 2 << '\n';
  cout << 2 << ' ' << 3 << '\n';
  cout << 3 << ' ' << 1 + n << '\n';
  cout << 1 + n << ' ' << 2 + n << '\n';
  cout << 2 + n << ' ' << 3 + n << '\n';
  for (int i = 5; i <= n; i += 2) {
    cout << "1 " << i - 1 << '\n';
    cout << "1 " << i << '\n';
    cout << i - 1 << ' ' << i + n << '\n';
    cout << i << ' ' << i - 1 + n << '\n';
  }
  if (n % 2 == 0) {
    cout << 1 / 0;
    cout << 1 << ' ' << n + n << '\n';
    cout << n - 2 << ' ' << n << '\n';
  }

  return 0;
}


Fixed submission:
#include <bits/stdc++.h>
#pragma GCC optimize("O2,unroll-loops")
// #pragma GCC optimize("no-stack-protector,fast-math")
// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")

using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<pii, int> piii;
typedef pair<ll, ll> pll;
#define debug(x) cerr << #x << '=' << (x) << endl;
#define debugp(x)                                                              \
  cerr << #x << "= {" << (x.first) << ", " << (x.second) << "}" << endl;
#define debug2(x, y)                                                           \
  cerr << "{" << #x << ", " << #y << "} = {" << (x) << ", " << (y) << "}"      \
       << endl;
#define debugv(v)                                                              \
  {                                                                            \
    cerr << #v << " : ";                                                       \
    for (auto x : v)                                                           \
      cerr << x << ' ';                                                        \
    cerr << endl;                                                              \
  }
#define all(x) x.begin(), x.end()
#define pb push_back
#define kill(x) return cout << x << '\n', 0;

const ld eps = 1e-7;
const int inf = 1000000010;
const ll INF = 10000000000000010LL;
const int mod = 1000000007;
const int MAXN = 100010, LOG = 20;

int n, m, k, u, v, x, y, t, a, b, ans;
int A[MAXN];

int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  // freopen("input.txt", "r", stdin);
  // freopen("output.txt", "w", stdout);
  cin >> n;
  if ((n & -n) == n)
    kill("No") cout << "Yes\n";
  cout << 1 << ' ' << 2 << '\n';
  cout << 2 << ' ' << 3 << '\n';
  cout << 3 << ' ' << 1 + n << '\n';
  cout << 1 + n << ' ' << 2 + n << '\n';
  cout << 2 + n << ' ' << 3 + n << '\n';
  for (int i = 5; i <= n; i += 2) {
    cout << "1 " << i - 1 << '\n';
    cout << "1 " << i << '\n';
    cout << i - 1 << ' ' << i + n << '\n';
    cout << i << ' ' << i - 1 + n << '\n';
  }
  if (n % 2 == 0) {
    int lb = (n & -n);
    cout << lb << ' ' << n + n << '\n';
    cout << (n ^ lb ^ 1) << ' ' << n << '\n';
  }

  return 0;
}