Problem p02599 (C++) — buggy submission, verdict: Runtime Error

#define _CRT_SECURE_NO_WARNINGS
#pragma comment(linker, "/stack:512000000")
#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <ccomplex>
#include <chrono>
#include <climits>
#include <cmath>
#include <cstdio>
#include <cstring>
#include <ctime>
#include <deque>
#include <fstream>
#include <functional>
#include <iostream>
#include <map>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

#ifdef ONLINE_JUDGE
#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,tune=native")
#pragma GCC optimize("unroll-loops")
#define int128 __int128
#else
#define int128 long long
#endif

#define all(x) x.begin(), x.end()
#define make_unique(x)                                                         \\
  sort(all((x)));                                                              \\
  (x).resize(unique(all((x))) - (x).begin())
#define mp make_pair
#define X first
#define Y second

using namespace std;

using ll = long long;
using ull = unsigned long long;
using ld = long double;
mt19937_64 gen(time(nullptr));

struct custom_hash {
  static uint64_t splitmix64(uint64_t x) {
    // http://xorshift.di.unimi.it/splitmix64.c
    x += 0x9e3779b97f4a7c15;
    x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
    x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
    return x ^ (x >> 31);
  }

  size_t operator()(uint64_t x) const {
    static const uint64_t FIXED_RANDOM =
        chrono::steady_clock::now().time_since_epoch().count();
    return splitmix64(x + FIXED_RANDOM);
  }
};

ll mod = 1e9 + 7;

namespace {
ll mul(ll a, ll b) {
  ll val = a * b - (ll)((ld)a * b / mod) * mod;
  if (val < 0)
    val += mod;
  if (val >= mod)
    val -= mod;
  return val;
}
ll poww(ll a, ll b) {
  ll val = 1;
  a %= mod;
  while (b > 0) {
    if (b % 2)
      val = mul(a, val);
    a = mul(a, a);
    b >>= 1;
  }
  return val % mod;
}
ll inv(ll a) { return poww(a, mod - 2); }
} // namespace

ll const maxn = 5e5 + 5;
struct FenwickTree {
  vector<ll> bit; // binary indexed tree
  ll n;

  FenwickTree(ll n) {
    this->n = n;
    bit.assign(n, 0);
  }

  FenwickTree(vector<ll> a) : FenwickTree(a.size()) {
    for (size_t i = 0; i < a.size(); i++)
      add(i, a[i]);
  }

  ll sum(ll r) {
    ll ret = 0;
    for (; r >= 0; r = (r & (r + 1)) - 1)
      ret += bit[r];
    return ret;
  }

  ll sum(ll l, ll r) { return sum(r) - sum(l - 1); }

  void add(ll idx, ll delta) {
    for (; idx < n; idx = idx | (idx + 1))
      bit[idx] += delta;
  }
};

signed main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  // freopen("output.txt", "w", stdout);
  ll n, q;
  cin >> n >> q;
  vector<ll> a(n);
  vector<vector<ll>> g(n + 1);
  for (ll i = 0; i < n; i++)
    cin >> a[i], g[a[i]].push_back(i);
  ll rofl = n;
  vector<ll> b(n);
  for (ll i = 0; i <= n; i++) {
    for (ll j = 0; j < g[i].size(); j++) {
      b[g[i][j]] = (j < (ll)g[i].size() - 1 ? g[i][j + 1] : rofl++);
    }
  }
  auto fw = FenwickTree(2 * n + 1);

  vector<vector<ll>> gr(n);
  vector<vector<pair<ll, ll>>> gl(n);

  for (ll i = 0; i < q; i++) {
    ll l, r;
    cin >> l >> r;
    l--, r--;
    gl[l].push_back({i, r});
    gr[r].push_back(i);
  }

  vector<ll> ans(q);
  for (ll i = 0; i < n; i++) {
    for (auto p : gl[i]) {
      ll l = i;
      ll r = p.Y, id = p.X;
      ans[id] -= fw.sum(r + 1, 2 * n);
    }
    fw.add(b[i], 1);
    for (ll id : gr[i]) {
      ll r = i;
      ans[id] += fw.sum(r + 1, 2 * n);
    }
  }

  for (ll i = 0; i < q; i++) {
    cout << ans[i] << '\\n';
  }

  return 0;
}

/*

*/

Error: 0

Fixed submission:

#define _CRT_SECURE_NO_WARNINGS
#pragma comment(linker, "/stack:512000000")
#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <ccomplex>
#include <chrono>
#include <climits>
#include <cmath>
#include <cstdio>
#include <cstring>
#include <ctime>
#include <deque>
#include <fstream>
#include <functional>
#include <iostream>
#include <map>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

#ifdef ONLINE_JUDGE
#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,tune=native")
#pragma GCC optimize("unroll-loops")
#define int128 __int128
#else
#define int128 long long
#endif

#define all(x) x.begin(), x.end()
#define make_unique(x)                                                         \\
  sort(all((x)));                                                              \\
  (x).resize(unique(all((x))) - (x).begin())
#define mp make_pair
#define X first
#define Y second

using namespace std;

using ll = long long;
using ull = unsigned long long;
using ld = long double;
mt19937_64 gen(time(nullptr));

struct custom_hash {
  static uint64_t splitmix64(uint64_t x) {
    // http://xorshift.di.unimi.it/splitmix64.c
    x += 0x9e3779b97f4a7c15;
    x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
    x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
    return x ^ (x >> 31);
  }

  size_t operator()(uint64_t x) const {
    static const uint64_t FIXED_RANDOM =
        chrono::steady_clock::now().time_since_epoch().count();
    return splitmix64(x + FIXED_RANDOM);
  }
};

ll mod = 1e9 + 7;

namespace {
ll mul(ll a, ll b) {
  ll val = a * b - (ll)((ld)a * b / mod) * mod;
  if (val < 0)
    val += mod;
  if (val >= mod)
    val -= mod;
  return val;
}
ll poww(ll a, ll b) {
  ll val = 1;
  a %= mod;
  while (b > 0) {
    if (b % 2)
      val = mul(a, val);
    a = mul(a, a);
    b >>= 1;
  }
  return val % mod;
}
ll inv(ll a) { return poww(a, mod - 2); }
} // namespace

ll const maxn = 5e5 + 5;
struct FenwickTree {
  vector<ll> bit; // binary indexed tree
  ll n;

  FenwickTree(ll n) {
    this->n = n;
    bit.assign(n, 0);
  }

  FenwickTree(vector<ll> a) : FenwickTree(a.size()) {
    for (size_t i = 0; i < a.size(); i++)
      add(i, a[i]);
  }

  ll sum(ll r) {
    ll ret = 0;
    for (; r >= 0; r = (r & (r + 1)) - 1)
      ret += bit[r];
    return ret;
  }

  ll sum(ll l, ll r) { return sum(r) - sum(l - 1); }

  void add(ll idx, ll delta) {
    for (; idx < n; idx = idx | (idx + 1))
      bit[idx] += delta;
  }
};

signed main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  // freopen("output.txt", "w", stdout);
  ll n, q;
  cin >> n >> q;
  vector<ll> a(n);
  vector<vector<ll>> g(n);
  for (ll i = 0; i < n; i++)
    cin >> a[i], g[a[i]].push_back(i);
  ll rofl = n;
  vector<ll> b(n);
  for (ll i = 0; i < n; i++) {
    for (ll j = 0; j < g[i].size(); j++) {
      b[g[i][j]] = (j < (ll)g[i].size() - 1 ? g[i][j + 1] : rofl++);
    }
  }
  vector<ll> kek(2 * n + 1);
  auto fw = FenwickTree(kek);

  vector<vector<ll>> gr(n);
  vector<vector<pair<ll, ll>>> gl(n);

  for (ll i = 0; i < q; i++) {
    ll l, r;
    cin >> l >> r;
    l--, r--;
    gl[l].push_back({i, r});
    gr[r].push_back(i);
  }

  vector<ll> ans(q);
  for (ll i = 0; i < n; i++) {
    for (auto p : gl[i]) {
      ll l = i;
      ll r = p.Y, id = p.X;
      ans[id] -= fw.sum(2 * n) - fw.sum(r);
    }
    fw.add(b[i], 1);
    for (ll id : gr[i]) {
      ll r = i;
      ans[id] += fw.sum(2 * n) - fw.sum(r);
    }
  }

  for (ll i = 0; i < q; i++) {
    cout << ans[i] << '\\n';
  }

  return 0;
}

/*

*/