Problem p02838 (C++)

Buggy submission (status: Runtime Error):
// #include <bits/stdc++.h>
#include <algorithm>
#include <cmath>
#include <iomanip>
#include <ios>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <stack>
// #include <windows.h>
using namespace std;
template <class T> using V = vector<T>;
template <class T> using VV = V<V<T>>;
template <class T> using VVV = V<VV<T>>;
template <class T1, class T2> using P = pair<T1, T2>;
using I = int;
using D = double;
using B = bool;
using C = char;
using S = string;
using LL = long long;
using LD = long double;
using ULL = unsigned long long;
using PII = P<I, I>;
using VPII = V<PII>;
using PLL = P<LL, LL>;
using VPLL = V<PLL>;
using VI = V<I>;
using VVI = VV<I>;
using VLL = V<LL>;
using VVLL = VV<LL>;
using VC = V<C>;
using VVC = VV<C>;
using VS = V<S>;
using VVS = VV<S>;
using VB = V<B>;
using VVB = VV<B>;
#define REP(type, i, n) for (type i = 0; i < (type)(n); ++i)
#define REP2(type, i, m, n) for (type i = (m); i < (type)(n); ++i)
#define REPR(type, i, n) for (type i = (n)-1; i >= 0; --i)
#define REPR2(type, i, m, n) for (type i = (n)-1; i >= (m); --i)
#define REPx(x, a) for (auto x : a)
#define ALL(a) a.begin(), a.end()
#define SORT(a) sort(ALL(a))
#define SORTR(a, type) sort(ALL(a), greater<type>())
#define SORTF(a, comp) sort(ALL(a), comp)
#define REVERSE(a) reverse(ALL(a))
#define SIZE(a, type) ((type)(a).size())
#define bit_search(bit, n) REP(LL, bit, 1LL << (n))
#define bit_check(bit, i) ((bit >> (i)) & 1)
#define setpre(n) fixed << setprecision((n))
#define UNIQUE(a)                                                              \
  do {                                                                         \
    SORT(a);                                                                   \
    (a).erase(unique(ALL(a)), (a).end());                                      \
  } while (0)
#define MAX(a) *max_element(ALL(a))
#define MIN(a) *min_element(ALL(a))
#define bisect_left(a, x) lower_bound(ALL(a), (x)) - a.begin()
#define bisect_right(a, x) upper_bound(ALL(a), (x)) - a.begin()
#define INPUT(a) REPx(&x, a) cin >> x;
#define INPUT2(a) REPx(&x, a) INPUT(x);
#define INPUTP(a) REPx(&x, a) cin >> x.first >> x.second;
#define ENDL cout << endl;

const int INF = 2e9;
// const LL INF = 9e18;
const LL MOD = 1e9 + 7;

template <class T> using PRIORITY_QUEUE = priority_queue<T, V<T>, greater<T>>;
template <class T> inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
template <class T> inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
template <class T> inline void debug1(V<T> A) {
  REP(int, i, SIZE(A, int)) {
    if (A[i] == INF)
      cout << "I ";
    else
      cout << A[i] << " ";
  }
  ENDL
}
template <class T> inline void debug2(VV<T> A) {
  REP(int, i, SIZE(A, int)) {
    REP(int, j, SIZE(A[i], int)) {
      if (A[i][j] == INF)
        cout << "I ";
      else
        cout << A[i][j] << " ";
    }
    ENDL
  }
}

template <class T> string D2BC(T d) {
  string res = "";
  while (d > 0) {
    if (d & 1)
      res += "1";
    else
      res += "0";
    d >>= 1;
  }
  REVERSE(res);
  return res;
}

// modをとる整数型
const int mod = 1e9 + 7;
struct mint {
  LL x;

  mint(LL _x = 0) : x((_x % mod + mod) % mod) {}

  mint operator-() const {
    mint tmp(-x);
    return tmp;
  }
  mint &operator+=(const mint &a) {
    if ((x += a.x) >= mod)
      x -= mod;
    return *this;
  }
  mint &operator-=(const mint &a) {
    if ((x += mod - a.x) >= mod)
      x -= mod;
    return *this;
  }
  mint &operator*=(const mint &a) {
    (x *= a.x) %= mod;
    return *this;
  }
  mint operator+(const mint &a) const {
    mint tmp(x);
    tmp += a.x;
    return tmp;
  }
  mint operator-(const mint &a) const {
    mint tmp(x);
    tmp -= a.x;
    return tmp;
  }
  mint operator*(const mint &a) const {
    mint tmp(x);
    tmp *= a.x;
    return tmp;
  }

  mint pow(LL b) const {
    mint res(1), a = *this;
    while (b > 0) {
      if (b & 1)
        res *= a;
      a *= a;
      b >>= 1;
    }
    return res;
  }

  mint inv() const { return pow(mod - 2); }
  mint &operator/=(const mint &a) { return *this *= a.inv(); }
  mint operator/(const mint &a) const {
    mint tmp(x);
    tmp /= a;
    return tmp;
  }
};
istream &operator>>(istream &is, mint &a) { return is >> a.x; }
ostream &operator<<(ostream &os, const mint &a) { return os << a.x; }

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  int n;
  cin >> n;
  VLL A(n);
  INPUT(A);
  int digit = int(log2(MAX(A))) + 1;
  VVI ct_1(n + 1, VI(digit, 0)), ct_0(n + 1, VI(digit, 1));
  REP(int, i, digit) ct_0[0][i] = 0;
  REP2(int, i, 1, n + 1) {
    VI tmp_1(digit, 0), tmp_0(digit, 1);
    LL j = A[i - 1], c = 0;
    while (j) {
      if (j & 1) {
        ++tmp_1[c];
        --tmp_0[c];
      }
      j >>= 1;
      ++c;
    }
    REP(int, j, digit) {
      ct_1[i][j] = tmp_1[j] + ct_1[i - 1][j];
      ct_0[i][j] = tmp_0[j] + ct_0[i - 1][j];
    }
  }
  mint ans = 0;
  REP2(int, i, 1, n) {
    VI tmp_1(digit), tmp_0(digit);
    REP(int, j, digit) {
      tmp_1[j] = ct_1[n][j] - ct_1[i][j];
      tmp_0[j] = ct_0[n][j] - ct_0[i][j];
    }
    LL j = A[i - 1], c = 0;
    while (j) {
      if (j & 1)
        tmp_1[c] = tmp_0[c];
      j >>= 1;
      ++c;
    }
    REP(int, i, digit) {
      mint x = 2;
      ans += x.pow(i) * tmp_1[i];
    }
  }
  cout << ans << endl;

  return 0;
}


Fixed submission:
// #include <bits/stdc++.h>
#include <algorithm>
#include <cmath>
#include <iomanip>
#include <ios>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <stack>
// #include <windows.h>
using namespace std;
template <class T> using V = vector<T>;
template <class T> using VV = V<V<T>>;
template <class T> using VVV = V<VV<T>>;
template <class T1, class T2> using P = pair<T1, T2>;
using I = int;
using D = double;
using B = bool;
using C = char;
using S = string;
using LL = long long;
using LD = long double;
using ULL = unsigned long long;
using PII = P<I, I>;
using VPII = V<PII>;
using PLL = P<LL, LL>;
using VPLL = V<PLL>;
using VI = V<I>;
using VVI = VV<I>;
using VLL = V<LL>;
using VVLL = VV<LL>;
using VC = V<C>;
using VVC = VV<C>;
using VS = V<S>;
using VVS = VV<S>;
using VB = V<B>;
using VVB = VV<B>;
#define REP(type, i, n) for (type i = 0; i < (type)(n); ++i)
#define REP2(type, i, m, n) for (type i = (m); i < (type)(n); ++i)
#define REPR(type, i, n) for (type i = (n)-1; i >= 0; --i)
#define REPR2(type, i, m, n) for (type i = (n)-1; i >= (m); --i)
#define REPx(x, a) for (auto x : a)
#define ALL(a) a.begin(), a.end()
#define SORT(a) sort(ALL(a))
#define SORTR(a, type) sort(ALL(a), greater<type>())
#define SORTF(a, comp) sort(ALL(a), comp)
#define REVERSE(a) reverse(ALL(a))
#define SIZE(a, type) ((type)(a).size())
#define bit_search(bit, n) REP(LL, bit, 1LL << (n))
#define bit_check(bit, i) ((bit >> (i)) & 1)
#define setpre(n) fixed << setprecision((n))
#define UNIQUE(a)                                                              \
  do {                                                                         \
    SORT(a);                                                                   \
    (a).erase(unique(ALL(a)), (a).end());                                      \
  } while (0)
#define MAX(a) *max_element(ALL(a))
#define MIN(a) *min_element(ALL(a))
#define bisect_left(a, x) lower_bound(ALL(a), (x)) - a.begin()
#define bisect_right(a, x) upper_bound(ALL(a), (x)) - a.begin()
#define INPUT(a) REPx(&x, a) cin >> x;
#define INPUT2(a) REPx(&x, a) INPUT(x);
#define INPUTP(a) REPx(&x, a) cin >> x.first >> x.second;
#define ENDL cout << endl;

const int INF = 2e9;
// const LL INF = 9e18;
const LL MOD = 1e9 + 7;

template <class T> using PRIORITY_QUEUE = priority_queue<T, V<T>, greater<T>>;
template <class T> inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
template <class T> inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
template <class T> inline void debug1(V<T> A) {
  REP(int, i, SIZE(A, int)) {
    if (A[i] == INF)
      cout << "I ";
    else
      cout << A[i] << " ";
  }
  ENDL
}
template <class T> inline void debug2(VV<T> A) {
  REP(int, i, SIZE(A, int)) {
    REP(int, j, SIZE(A[i], int)) {
      if (A[i][j] == INF)
        cout << "I ";
      else
        cout << A[i][j] << " ";
    }
    ENDL
  }
}

template <class T> string D2BC(T d) {
  string res = "";
  while (d > 0) {
    if (d & 1)
      res += "1";
    else
      res += "0";
    d >>= 1;
  }
  REVERSE(res);
  return res;
}

// modをとる整数型
const int mod = 1e9 + 7;
struct mint {
  LL x;

  mint(LL _x = 0) : x((_x % mod + mod) % mod) {}

  mint operator-() const {
    mint tmp(-x);
    return tmp;
  }
  mint &operator+=(const mint &a) {
    if ((x += a.x) >= mod)
      x -= mod;
    return *this;
  }
  mint &operator-=(const mint &a) {
    if ((x += mod - a.x) >= mod)
      x -= mod;
    return *this;
  }
  mint &operator*=(const mint &a) {
    (x *= a.x) %= mod;
    return *this;
  }
  mint operator+(const mint &a) const {
    mint tmp(x);
    tmp += a.x;
    return tmp;
  }
  mint operator-(const mint &a) const {
    mint tmp(x);
    tmp -= a.x;
    return tmp;
  }
  mint operator*(const mint &a) const {
    mint tmp(x);
    tmp *= a.x;
    return tmp;
  }

  mint pow(LL b) const {
    mint res(1), a = *this;
    while (b > 0) {
      if (b & 1)
        res *= a;
      a *= a;
      b >>= 1;
    }
    return res;
  }

  mint inv() const { return pow(mod - 2); }
  mint &operator/=(const mint &a) { return *this *= a.inv(); }
  mint operator/(const mint &a) const {
    mint tmp(x);
    tmp /= a;
    return tmp;
  }
};
istream &operator>>(istream &is, mint &a) { return is >> a.x; }
ostream &operator<<(ostream &os, const mint &a) { return os << a.x; }

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  int n;
  cin >> n;
  VLL A(n);
  INPUT(A);
  int digit;
  if (MAX(A) == 0)
    digit = 1;
  else
    digit = int(log2(MAX(A))) + 1;
  VVI ct_1(n + 1, VI(digit, 0)), ct_0(n + 1, VI(digit, 1));
  REP(int, i, digit) ct_0[0][i] = 0;
  REP2(int, i, 1, n + 1) {
    VI tmp_1(digit, 0), tmp_0(digit, 1);
    LL j = A[i - 1], c = 0;
    while (j) {
      if (j & 1) {
        ++tmp_1[c];
        --tmp_0[c];
      }
      j >>= 1;
      ++c;
    }
    REP(int, j, digit) {
      ct_1[i][j] = tmp_1[j] + ct_1[i - 1][j];
      ct_0[i][j] = tmp_0[j] + ct_0[i - 1][j];
    }
  }
  mint ans = 0;
  REP2(int, i, 1, n) {
    VI tmp_1(digit), tmp_0(digit);
    REP(int, j, digit) {
      tmp_1[j] = ct_1[n][j] - ct_1[i][j];
      tmp_0[j] = ct_0[n][j] - ct_0[i][j];
    }
    LL j = A[i - 1], c = 0;
    while (j) {
      if (j & 1)
        tmp_1[c] = tmp_0[c];
      j >>= 1;
      ++c;
    }
    REP(int, i, digit) {
      mint x = 2;
      ans += x.pow(i) * tmp_1[i];
    }
  }
  cout << ans << endl;

  return 0;
}