Problem p03749 (C++)

Buggy submission (status: Time Limit Exceeded):
#include <bits/stdc++.h>
using namespace std;

typedef long long signed int LL;
typedef long long unsigned int LU;

#define incID(i, l, r) for (int i = (l); i < (r); i++)
#define incII(i, l, r) for (int i = (l); i <= (r); i++)
#define decID(i, l, r) for (int i = (r)-1; i >= (l); i--)
#define decII(i, l, r) for (int i = (r); i >= (l); i--)
#define inc(i, n) incID(i, 0, n)
#define inc1(i, n) incII(i, 1, n)
#define dec(i, n) decID(i, 0, n)
#define dec1(i, n) decII(i, 1, n)

#define inII(v, l, r) ((l) <= (v) && (v) <= (r))
#define inID(v, l, r) ((l) <= (v) && (v) < (r))

#define PB push_back
#define EB emplace_back
#define MP make_pair
#define FI first
#define SE second
#define PQ priority_queue

#define ALL(v) v.begin(), v.end()
#define RALL(v) v.rbegin(), v.rend()
#define FOR(it, v) for (auto it = v.begin(); it != v.end(); ++it)
#define RFOR(it, v) for (auto it = v.rbegin(); it != v.rend(); ++it)

template <typename T> bool setmin(T &a, T b) {
  if (b < a) {
    a = b;
    return true;
  } else {
    return false;
  }
}
template <typename T> bool setmax(T &a, T b) {
  if (b > a) {
    a = b;
    return true;
  } else {
    return false;
  }
}
template <typename T> bool setmineq(T &a, T b) {
  if (b <= a) {
    a = b;
    return true;
  } else {
    return false;
  }
}
template <typename T> bool setmaxeq(T &a, T b) {
  if (b >= a) {
    a = b;
    return true;
  } else {
    return false;
  }
}
template <typename T> T gcd(T a, T b) { return (b == 0 ? a : gcd(b, a % b)); }
template <typename T> T lcm(T a, T b) { return a / gcd(a, b) * b; }

// ---- ----

template <typename T, int N> struct Matrix {
  vector<vector<T>> a;
  Matrix(const vector<vector<T>> &v = {}) { init(v); }
  void init(const vector<vector<T>> &v) {
    a = vector<vector<T>>(N, vector<T>(N, 0));
    assert(v.size() <= N);
    inc(i, v.size()) {
      assert(v[i].size() <= N);
      inc(j, v[i].size()) { a[i][j] = v[i][j]; }
    }
  }
  vector<T> &operator[](int i) { return a[i]; }
  Matrix id() {
    Matrix e;
    inc(i, N) { e[i][i] = 1; }
    return e;
  }
  Matrix tp() {
    Matrix b;
    inc(i, N) {
      inc(j, N) { b[j][i] = a[i][j]; }
    }
    return b;
  }
  Matrix &operator+=(const Matrix &b) {
    inc(i, N) {
      inc(j, N) { a[i][j] += b.a[i][j]; }
    }
    return (*this);
  }
  Matrix &operator*=(T b) {
    inc(i, N) {
      inc(j, N) { a[i][j] *= b; }
    }
    return (*this);
  }
  Matrix &operator*=(const Matrix &b) {
    Matrix c;
    inc(i, N) {
      inc(j, N) {
        inc(k, N) { c[i][j] += a[i][k] * b.a[k][j]; }
      }
    }
    return (*this) = c;
  }
  Matrix &operator^=(LU b) {
    Matrix t[64], c = id();
    int D = 64;
    inc(i, D) {
      if ((b >> i) == 0) {
        D = i;
        break;
      }
    }
    inc(i, D) { t[i] = (i == 0 ? (*this) : t[i - 1] * t[i - 1]); }
    inc(i, D) {
      if ((b >> i) & 1) {
        c *= t[i];
      }
    }
    return (*this) = c;
  }
  Matrix operator+(const Matrix &b) const {
    Matrix c = a;
    return c += b;
  }
  Matrix operator*(T b) const {
    Matrix c = a;
    return c *= b;
  }
  Matrix operator*(const Matrix &b) const {
    Matrix c = a;
    return c *= b;
  }
  Matrix operator^(LU b) const {
    Matrix c = a;
    return c ^= b;
  }
};
template <typename T, int N>
Matrix<T, N> operator*(T a, const Matrix<T, N> &b) {
  return b * a;
}
template <typename T, int N>
ostream &operator<<(ostream &os, const Matrix<T, N> &m) {
  inc(i, N) {
    inc(j, N) { os << m.a[i][j] << " "; }
    os << endl;
  }
  return os;
}

// ---- ----

template <int N = 0> class ModInt {
private:
  LL v = 0;
  static LL m;

public:
  ModInt() {}
  ModInt(LL vv) { setval(vv); }
  ModInt &setval(LL vv) {
    v = vv % m;
    if (v < 0) {
      v += m;
    }
    return (*this);
  }
  static void setmod(LL mm) { m = mm; }
  LL getval() const { return v; }
  ModInt &operator+=(const ModInt &b) { return setval(v + b.v); }
  ModInt &operator-=(const ModInt &b) { return setval(v - b.v); }
  ModInt &operator*=(const ModInt &b) { return setval(v * b.v); }
  ModInt &operator/=(const ModInt &b) { return setval(v * b.inv()); }
  ModInt &operator^=(LU b) { return setval(ex(v, b)); }
  ModInt operator+() const { return ModInt(+v); }
  ModInt operator-() const { return ModInt(-v); }
  ModInt operator+(const ModInt &b) const { return ModInt(v + b.v); }
  ModInt operator-(const ModInt &b) const { return ModInt(v - b.v); }
  ModInt operator*(const ModInt &b) const { return ModInt(v * b.v); }
  ModInt operator/(const ModInt &b) const { return ModInt(v * b.inv()); }
  ModInt operator^(LU b) const { return ModInt(ex(v, b)); }
  LL inv() const {
    LL x = (ex_gcd(v, m).FI + m) % m;
    assert(v * x % m == 1);
    return x;
  }
  LL ex(LL a, LU b) const {
    LL D = 64, x[64], y = 1;
    inc(i, D) {
      if ((b >> i) == 0) {
        D = i;
        break;
      }
    }
    inc(i, D) { x[i] = (i == 0 ? a : x[i - 1] * x[i - 1]) % m; }
    inc(i, D) {
      if ((b >> i) & 1) {
        (y *= x[i]) %= m;
      }
    }
    return y;
  }
  pair<LL, LL> ex_gcd(LL a, LL b) const {
    if (b == 0) {
      return MP(1, 0);
    }
    auto p = ex_gcd(b, a % b);
    return MP(p.SE, p.FI - (a / b) * p.SE);
  }
};
template <int N> LL ModInt<N>::m;
template <int N> ModInt<N> operator+(LL a, const ModInt<N> &b) { return b + a; }
template <int N> ModInt<N> operator-(LL a, const ModInt<N> &b) {
  return -b + a;
}
template <int N> ModInt<N> operator*(LL a, const ModInt<N> &b) { return b * a; }
template <int N> ModInt<N> operator/(LL a, const ModInt<N> &b) {
  return a * b.inv();
}
template <int N> istream &operator>>(istream &is, ModInt<N> &b) {
  LL v;
  is >> v;
  b.setval(v);
  return is;
}
template <int N> ostream &operator<<(ostream &os, const ModInt<N> &b) {
  return (os << b.getval());
}

// ---- ----

int n, m, x[100002];

int main() {
  cin >> n >> m;
  x[0] = 0;
  inc1(i, m) { cin >> x[i]; }
  x[m + 1] = n;

  ModInt<>::setmod(1e9 + 7);
  Matrix<ModInt<>, 3> a({{1, 0, 0}, {1, 1, 0}, {0, 1, 1}});
  Matrix<ModInt<>, 3> b({{2, 3, 2}, {1, 1, 0}, {0, 1, 1}});
  Matrix<ModInt<>, 3> c({{0, 1, 2}});

  incII(i, 0, m) { c *= a * (b ^ (x[i + 1] - x[i] - 1)); }

  cout << c[0][0] << endl;

  return 0;
}


Fixed submission:
#include <bits/stdc++.h>
using namespace std;

typedef long long signed int LL;
typedef long long unsigned int LU;

#define incID(i, l, r) for (int i = (l); i < (r); i++)
#define incII(i, l, r) for (int i = (l); i <= (r); i++)
#define decID(i, l, r) for (int i = (r)-1; i >= (l); i--)
#define decII(i, l, r) for (int i = (r); i >= (l); i--)
#define inc(i, n) incID(i, 0, n)
#define inc1(i, n) incII(i, 1, n)
#define dec(i, n) decID(i, 0, n)
#define dec1(i, n) decII(i, 1, n)

#define inII(v, l, r) ((l) <= (v) && (v) <= (r))
#define inID(v, l, r) ((l) <= (v) && (v) < (r))

#define PB push_back
#define EB emplace_back
#define MP make_pair
#define FI first
#define SE second
#define PQ priority_queue

#define ALL(v) v.begin(), v.end()
#define RALL(v) v.rbegin(), v.rend()
#define FOR(it, v) for (auto it = v.begin(); it != v.end(); ++it)
#define RFOR(it, v) for (auto it = v.rbegin(); it != v.rend(); ++it)

template <typename T> bool setmin(T &a, T b) {
  if (b < a) {
    a = b;
    return true;
  } else {
    return false;
  }
}
template <typename T> bool setmax(T &a, T b) {
  if (b > a) {
    a = b;
    return true;
  } else {
    return false;
  }
}
template <typename T> bool setmineq(T &a, T b) {
  if (b <= a) {
    a = b;
    return true;
  } else {
    return false;
  }
}
template <typename T> bool setmaxeq(T &a, T b) {
  if (b >= a) {
    a = b;
    return true;
  } else {
    return false;
  }
}
template <typename T> T gcd(T a, T b) { return (b == 0 ? a : gcd(b, a % b)); }
template <typename T> T lcm(T a, T b) { return a / gcd(a, b) * b; }

// ---- ----

template <typename T, int N> struct Matrix {
  vector<vector<T>> a;
  Matrix(const vector<vector<T>> &v = {}) { init(v); }
  void init(const vector<vector<T>> &v) {
    a = vector<vector<T>>(N, vector<T>(N, 0));
    assert(v.size() <= N);
    inc(i, v.size()) {
      assert(v[i].size() <= N);
      inc(j, v[i].size()) { a[i][j] = v[i][j]; }
    }
  }
  vector<T> &operator[](int i) { return a[i]; }
  Matrix id() {
    Matrix e;
    inc(i, N) { e[i][i] = 1; }
    return e;
  }
  Matrix tp() {
    Matrix b;
    inc(i, N) {
      inc(j, N) { b[j][i] = a[i][j]; }
    }
    return b;
  }
  Matrix &operator+=(const Matrix &b) {
    inc(i, N) {
      inc(j, N) { a[i][j] += b.a[i][j]; }
    }
    return (*this);
  }
  Matrix &operator*=(T b) {
    inc(i, N) {
      inc(j, N) { a[i][j] *= b; }
    }
    return (*this);
  }
  Matrix &operator*=(const Matrix &b) {
    Matrix c;
    inc(i, N) {
      inc(j, N) {
        inc(k, N) { c[i][j] += a[i][k] * b.a[k][j]; }
      }
    }
    return (*this) = c;
  }
  Matrix &operator^=(LU b) {
    Matrix t[64], c = id();
    int D = 64;
    inc(i, D) {
      if ((b >> i) == 0) {
        D = i;
        break;
      }
    }
    inc(i, D) { t[i] = (i == 0 ? (*this) : t[i - 1] * t[i - 1]); }
    inc(i, D) {
      if ((b >> i) & 1) {
        c *= t[i];
      }
    }
    return (*this) = c;
  }
  Matrix operator+(const Matrix &b) const {
    Matrix c = a;
    return c += b;
  }
  Matrix operator*(T b) const {
    Matrix c = a;
    return c *= b;
  }
  Matrix operator*(const Matrix &b) const {
    Matrix c = a;
    return c *= b;
  }
  Matrix operator^(LU b) const {
    Matrix c = a;
    return c ^= b;
  }
};
template <typename T, int N>
Matrix<T, N> operator*(T a, const Matrix<T, N> &b) {
  return b * a;
}
template <typename T, int N>
ostream &operator<<(ostream &os, const Matrix<T, N> &m) {
  inc(i, N) {
    inc(j, N) { os << m.a[i][j] << " "; }
    os << endl;
  }
  return os;
}

// ---- ----

template <int N = 0> class ModInt {
private:
  LL v = 0;
  static LL m;

public:
  ModInt() {}
  ModInt(LL vv) { setval(vv); }
  ModInt &setval(LL vv) {
    v = (inID(vv, 0, m) ? vv : vv % m);
    if (v < 0) {
      v += m;
    }
    return (*this);
  }
  static void setmod(LL mm) { m = mm; }
  LL getval() const { return v; }
  ModInt &operator+=(const ModInt &b) { return setval(v + b.v); }
  ModInt &operator-=(const ModInt &b) { return setval(v - b.v); }
  ModInt &operator*=(const ModInt &b) { return setval(v * b.v); }
  ModInt &operator/=(const ModInt &b) { return setval(v * b.inv()); }
  ModInt &operator^=(LU b) { return setval(ex(v, b)); }
  ModInt operator+() const { return ModInt(+v); }
  ModInt operator-() const { return ModInt(-v); }
  ModInt operator+(const ModInt &b) const { return ModInt(v + b.v); }
  ModInt operator-(const ModInt &b) const { return ModInt(v - b.v); }
  ModInt operator*(const ModInt &b) const { return ModInt(v * b.v); }
  ModInt operator/(const ModInt &b) const { return ModInt(v * b.inv()); }
  ModInt operator^(LU b) const { return ModInt(ex(v, b)); }
  LL inv() const {
    LL x = (ex_gcd(v, m).FI + m) % m;
    assert(v * x % m == 1);
    return x;
  }
  LL ex(LL a, LU b) const {
    LL D = 64, x[64], y = 1;
    inc(i, D) {
      if ((b >> i) == 0) {
        D = i;
        break;
      }
    }
    inc(i, D) { x[i] = (i == 0 ? a : x[i - 1] * x[i - 1]) % m; }
    inc(i, D) {
      if ((b >> i) & 1) {
        (y *= x[i]) %= m;
      }
    }
    return y;
  }
  pair<LL, LL> ex_gcd(LL a, LL b) const {
    if (b == 0) {
      return MP(1, 0);
    }
    auto p = ex_gcd(b, a % b);
    return MP(p.SE, p.FI - (a / b) * p.SE);
  }
};
template <int N> LL ModInt<N>::m;
template <int N> ModInt<N> operator+(LL a, const ModInt<N> &b) { return b + a; }
template <int N> ModInt<N> operator-(LL a, const ModInt<N> &b) {
  return -b + a;
}
template <int N> ModInt<N> operator*(LL a, const ModInt<N> &b) { return b * a; }
template <int N> ModInt<N> operator/(LL a, const ModInt<N> &b) {
  return a * b.inv();
}
template <int N> istream &operator>>(istream &is, ModInt<N> &b) {
  LL v;
  is >> v;
  b.setval(v);
  return is;
}
template <int N> ostream &operator<<(ostream &os, const ModInt<N> &b) {
  return (os << b.getval());
}

// ---- ----

int n, m, x[100002];

int main() {
  cin >> n >> m;
  x[0] = 0;
  inc1(i, m) { cin >> x[i]; }
  x[m + 1] = n;

  ModInt<>::setmod(1e9 + 7);
  Matrix<ModInt<>, 3> a({{1, 0, 0}, {1, 1, 0}, {0, 1, 1}});
  Matrix<ModInt<>, 3> b({{2, 3, 2}, {1, 1, 0}, {0, 1, 1}});
  Matrix<ModInt<>, 3> c({{0, 1, 2}});

  incII(i, 0, m) { c *= a * (b ^ (x[i + 1] - x[i] - 1)); }

  cout << c[0][0] << endl;

  return 0;
}