Problem p03987 (C++)

Buggy submission (status: Time Limit Exceeded):
#include <bits/stdc++.h>
using namespace std;
#define FOR(i, o, n) for (long long i = o; i < n; i++)
#define oneforall                                                              \
  ios::sync_with_stdio(false);                                                 \
  cin.tie(0);
#define all(v) (v).begin(), (v).end()
#define ini(...)                                                               \
  int __VA_ARGS__;                                                             \
  in(__VA_ARGS__)
#define inl(...)                                                               \
  long long __VA_ARGS__;                                                       \
  in(__VA_ARGS__)
#define ins(...)                                                               \
  string __VA_ARGS__;                                                          \
  in(__VA_ARGS__)
#define int long long
const long long inf = 1e18;
void in() {}
template <typename T, class... U> void in(T &t, U &...u) {
  cin >> t;
  in(u...);
}
void out() { cout << "\n"; }
template <typename T, class... U> void out(const T &t, const U &...u) {
  cout << t;
  if (sizeof...(u))
    cout << " ";
  out(u...);
}
typedef vector<int> vi;
typedef vector<long long> vl;
typedef long long ll;
typedef vector<pair<long, long>> vpll;
typedef vector<pair<int, int>> vpii;
#define FORR(x, arr) for (auto &x : arr)
#define ZERO(a) memset(a, 0, sizeof(a))

// 3111111111111111111111111111111

void solve() {

  ini(n);
  vi morty(n + 1);
  vi pos(n + 1);
  int rick = 0;
  FOR(i, 1, n + 1) {
    in(morty[i]);
    pos[morty[i]] = i;
  }
  set<int> set1;
  set1.insert(0);
  set1.insert(n + 1);
  FOR(i, 1, n + 1) {
    auto pos1 = upper_bound(all(set1), pos[i]);
    int rr = *pos1;
    pos1--;
    int ll = *pos1;
    rick += (1ll * i) * (rr - pos[i]) * (pos[i] - ll);
    set1.insert(pos[i]);
  }
  out(rick);
}

int32_t main() {
  oneforall oneforall oneforall oneforall oneforall oneforall oneforall
      oneforall oneforall oneforall oneforall oneforall oneforall oneforall

      solve();

  return 0;
}


Fixed submission:
#include <bits/stdc++.h>
using namespace std;
#define FOR(i, o, n) for (long long i = o; i < n; i++)
#define oneforall                                                              \
  ios::sync_with_stdio(false);                                                 \
  cin.tie(0);
#define all(v) (v).begin(), (v).end()
#define ini(...)                                                               \
  int __VA_ARGS__;                                                             \
  in(__VA_ARGS__)
#define inl(...)                                                               \
  long long __VA_ARGS__;                                                       \
  in(__VA_ARGS__)
#define ins(...)                                                               \
  string __VA_ARGS__;                                                          \
  in(__VA_ARGS__)
#define int long long
const long long inf = 1e18;
void in() {}
template <typename T, class... U> void in(T &t, U &...u) {
  cin >> t;
  in(u...);
}
void out() { cout << "\n"; }
template <typename T, class... U> void out(const T &t, const U &...u) {
  cout << t;
  if (sizeof...(u))
    cout << " ";
  out(u...);
}
typedef vector<int> vi;
typedef vector<long long> vl;
typedef long long ll;
typedef vector<pair<long, long>> vpll;
typedef vector<pair<int, int>> vpii;
#define FORR(x, arr) for (auto &x : arr)
#define ZERO(a) memset(a, 0, sizeof(a))

// 3111111111111111111111111111111

void solve() {

  ini(n);
  vi morty(n + 1);
  vi pos(n + 1);
  int rick = 0;
  FOR(i, 1, n + 1) {
    in(morty[i]);
    pos[morty[i]] = i;
  }
  set<int> set1;
  set1.insert(0);
  set1.insert(n + 1);
  FOR(i, 1, n + 1) {
    auto pos1 = set1.upper_bound(pos[i]);
    int rr = *pos1;
    pos1--;
    int ll = *pos1;
    rick += (1ll * i) * (rr - pos[i]) * (pos[i] - ll);
    set1.insert(pos[i]);
  }
  out(rick);
}

int32_t main() {
  oneforall oneforall oneforall oneforall oneforall oneforall oneforall
      oneforall oneforall oneforall oneforall oneforall oneforall oneforall

      solve();

  return 0;
}