Problem p03498 (C++)

Buggy submission (status: Runtime Error):
#include <bits/stdc++.h>
using namespace std;
#ifndef ONLINE_JUDGE
#define dbg(x...)                                                              \
  do {                                                                         \
    cout << "\033[32;1m " << #x << " -> ";                                     \
    err(x);                                                                    \
  } while (0)
void err() { cout << "\033[39;0m" << endl; }
template <template <typename...> class T, typename t, typename... A>
void err(T<t> a, A... x) {
  for (auto v : a)
    cout << v << ' ';
  err(x...);
}
template <typename T, typename... A> void err(T a, A... x) {
  cout << a << ' ';
  err(x...);
}
#else
#define dbg(...)
#endif
typedef long long ll;
typedef pair<int, int> pi;
typedef vector<int> vi;
template <class T> using vc = vector<T>;
template <class T> using vvc = vc<vc<T>>;
template <class T> void mkuni(vector<T> &v) {
  sort(v.begin(), v.end());
  v.erase(unique(v.begin(), v.end()), v.end());
}
template <class T> void print(T x, int suc = 1) {
  cout << x;
  if (suc == 1)
    cout << '\n';
  else
    cout << ' ';
}
template <class T> void print(const vector<T> &v, int suc = 1) {
  for (int i = 0; i < v.size(); i++)
    print(v[i], i == (int)(v.size()) - 1 ? suc : 2);
}
int main() {
  int n;
  cin >> n;
  vi a(n);
  int mx = 1, mi = 1;
  for (int i = 1; i <= n; i++) {
    cin >> a[i];
    if (a[mi] > a[i])
      mi = i;
    if (a[mx] < a[i])
      mx = i;
  }
  cout << 2 * n << '\n';
  if (abs(a[mx]) > abs(a[mi])) {
    cout << mx << " " << 1 << '\n';
    cout << mx << " " << 1 << '\n';
    for (int i = 2; i <= n; i++)
      cout << i - 1 << " " << i << '\n' << i - 1 << " " << i << '\n';
  } else {
    cout << mi << " " << n << '\n' << mi << " " << n << '\n';
    for (int i = n - 1; i >= 1; i--)
      cout << i + 1 << " " << i << "\n" << i + 1 << " " << i << '\n';
  }
}

Fixed submission:
#include <bits/stdc++.h>
using namespace std;
#ifndef ONLINE_JUDGE
#define dbg(x...)                                                              \
  do {                                                                         \
    cout << "\033[32;1m " << #x << " -> ";                                     \
    err(x);                                                                    \
  } while (0)
void err() { cout << "\033[39;0m" << endl; }
template <template <typename...> class T, typename t, typename... A>
void err(T<t> a, A... x) {
  for (auto v : a)
    cout << v << ' ';
  err(x...);
}
template <typename T, typename... A> void err(T a, A... x) {
  cout << a << ' ';
  err(x...);
}
#else
#define dbg(...)
#endif
typedef long long ll;
typedef pair<int, int> pi;
typedef vector<int> vi;
template <class T> using vc = vector<T>;
template <class T> using vvc = vc<vc<T>>;
template <class T> void mkuni(vector<T> &v) {
  sort(v.begin(), v.end());
  v.erase(unique(v.begin(), v.end()), v.end());
}
template <class T> void print(T x, int suc = 1) {
  cout << x;
  if (suc == 1)
    cout << '\n';
  else
    cout << ' ';
}
template <class T> void print(const vector<T> &v, int suc = 1) {
  for (int i = 0; i < v.size(); i++)
    print(v[i], i == (int)(v.size()) - 1 ? suc : 2);
}
int main() {
  int n;
  cin >> n;
  vi a(n + 1);
  int mx = 1, mi = 1;
  for (int i = 1; i <= n; i++) {
    cin >> a[i];
    if (a[mi] > a[i])
      mi = i;
    if (a[mx] < a[i])
      mx = i;
  }
  cout << 2 * n << '\n';
  if (abs(a[mx]) > abs(a[mi])) {
    cout << mx << " " << 1 << '\n';
    cout << mx << " " << 1 << '\n';
    for (int i = 2; i <= n; i++)
      cout << i - 1 << " " << i << '\n' << i - 1 << " " << i << '\n';
  } else {
    cout << mi << " " << n << '\n' << mi << " " << n << '\n';
    for (int i = n - 1; i >= 1; i--)
      cout << i + 1 << " " << i << "\n" << i + 1 << " " << i << '\n';
  }
}