Problem p02599 (C++)

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

// conversion
//------------------------------------------
inline int toInt(string s) {
  int v;
  istringstream sin(s);
  sin >> v;
  return v;
}
template <class T> inline string toString(T x) {
  ostringstream sout;
  sout << x;
  return sout.str();
}

// math
//-------------------------------------------
template <class T> inline T sqr(T x) { return x * x; }

// typedef
//------------------------------------------
typedef long long LL;
typedef pair<int, int> PII;
typedef pair<LL, LL> PLL;
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<LL> VLL;
typedef vector<VLL> VVLL;
typedef vector<bool> VB;
typedef vector<VB> VVB;
typedef vector<double> VD;
typedef vector<VD> VVD;
typedef vector<string> VS;
typedef vector<VS> VVS;
typedef vector<char> VC;
typedef vector<VC> VVC;
typedef vector<PII> VPII;
typedef vector<PLL> VPLL;
typedef priority_queue<int> PQGI; // 大きい順
typedef priority_queue<int, VI, greater<int>> PQLI;
typedef priority_queue<PII> PQGP;
typedef priority_queue<PII, VPII, greater<int>> PQLP;

// container util
//------------------------------------------
#define ALL(a) (a).begin(), (a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define EB emplace_back
#define PB push_back
#define PF push_front
#define POB pop_back
#define POF pop_front
#define MP make_pair
#define SZ(a) int((a).size())
#define SQ(a) ((a) * (a))
#define EACH(i, c)                                                             \
  for (typeof((c).begin()) i = (c).begin(); i != (c).end(); ++i)
#define EXIST(s, e) ((s).find(e) != (s).end())
#define SORT(c) sort((c).begin(), (c).end())
#define SORTR(c) sort((c).rbegin(), (c).rend())
#define LB lower_bound
#define UB upper_bound
#define NEXP next_permutation
#define FI first
#define SE second
#define Vmin(a) *min_element((a).begin(), (a).end())
#define Vmax(a) *max_element((a).begin(), (a).end())

// repetition
//------------------------------------------
#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define REP(i, n) FOR(i, 0, n)
#define FORR(i, a, b) for (int i = (b - 1); i >= (a); i--)
#define REPR(i, n) FORR(i, 0, n)
#define CFOR(i, a, b) for (int i = (a); i <= (b); ++i)
#define CREP(i, n) CFOR(i, 0, n)
#define CFORR(i, a, b) for (int i = (b); i >= (a); i--)
#define CREPR(i, n) CFORR(i, 0, n)
#define BFOR(bit, a, b) for (int bit = (a); bit < (1 << (b)); ++bit)
#define BREP(bit, n) BFOR(bit, 0, n)

// constant
//--------------------------------------------
const double EPS = 1e-10;
const double PI = acos(-1.0);
const int INF = INT_MAX / 2;
const LL LINF = LLONG_MAX / 3;
const int RINF = INT_MIN / 2;
const LL RLINF = LLONG_MIN / 3;
const LL MOD = 1e9 + 7;
const LL MODD = 998244353;
const int MAX = 510000;

inline bool Eq(double a, double b) { return fabs(b - a) < EPS; }

// other
//-------------------------------------------
template <class T> bool chmax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> bool chmin(T &a, const T &b) {
  if (b < a) {
    a = b;
    return 1;
  }
  return 0;
}

#define COUT(x) cout << (x) << endl
#define COUT2(x, y) cout << (x) << " " << (y) << endl
#define COUT3(x, y, z) cout << (x) << " " << (y) << " " << (z) << endl
#define PR(x) cout << (x)
#define ENDL cout << endl
#define SPACE cout << " "
#define BC(x) __builtin_popcountll(x)

VI dx = {1, 0, -1, 0, 1, 1, -1, -1};
VI dy = {0, 1, 0, -1, 1, -1, 1, -1};

LL Gcd(LL a, LL b) { return __gcd(a, b); }
LL Lcm(LL a, LL b) { return a / Gcd(a, b) * b; }

LL ModPow(LL A, LL N, LL M) {
  LL res = 1;
  while (N > 0) {
    if (N & 1)
      res = res * A % M;
    A = A * A % M;
    N >>= 1;
  }
  return res;
}

template <typename T1, typename T2>
istream &operator>>(istream &is, pair<T1, T2> &p) {
  is >> p.first >> p.second;
  return is;
}

template <typename T1, typename T2>
ostream &operator<<(ostream &os, const pair<T1, T2> &p) {
  os << p.first << " " << p.second;
  return os;
}

template <typename T> istream &operator>>(istream &is, vector<T> &v) {
  for (T &in : v)
    is >> in;
  return is;
}

template <typename T> ostream &operator<<(ostream &os, const vector<T> &v) {
  for (int i = 0; i < (int)v.size(); i++) {
    os << v[i] << (i + 1 != v.size() ? " " : "");
  }
  return os;
}

template <typename T> vector<T> make_v(size_t a, T b) {
  return vector<T>(a, b);
}
template <typename... Ts> auto make_v(size_t a, Ts... ts) {
  return vector<decltype(make_v(ts...))>(a, make_v(ts...));
}

struct str {
  int l, r, q;
  str(int l, int r, int q) : l(l), r(r), q(q) {}
};

template <typename T> struct SegmentTree {
  using OP = function<T(T, T)>;

  int n;
  vector<T> node;
  T t;
  OP op;

  SegmentTree(int n_, T t, OP op) : t(t), op(op) {
    n = 1;
    while (n < n_)
      n <<= 1;
    node.assign(2 * n, t);
  }

  void init(int n_) {
    n = 1;
    while (n < n_)
      n <<= 1;
    node.assign(2 * n, t);
  }

  void set(int k, T x) { node.at(k + n) = x; }

  void build() {
    for (int k = n - 1; k > 0; k--) {
      node.at(k) = op(node.at(2 * k), node.at(2 * k + 1));
    }
  }

  void update(int k, T x) {
    k += n;
    node.at(k) = x;
    while (k >>= 1) {
      node.at(k) = op(node.at(2 * k), node.at(2 * k + 1));
    }
  }

  void update(int l, int r, T x) { FOR(k, l, r) update(k, x); }

  T at(int k) { return node.at(k + n); }

  void add(int k, T a) {
    T x = at(k) + a;
    update(k, x);
  }

  T query(int a, int b) {
    T L = t, R = t;
    for (a += n, b += n; a < b; a >>= 1, b >>= 1) {
      if (a & 1)
        L = op(L, node.at(a++));
      if (b & 1)
        R = op(node.at(--b), R);
    }
    return op(L, R);
  }

  template <typename C> int findR(int a, int b, C &check) {
    return findR(a, b, check, 1, 0, n);
  }
  template <typename C> int findR(int a, int b, C &check, int k, int l, int r) {
    if (!check(node.at(k)) || r <= a || b <= l)
      return -1;
    if (k >= n)
      return k - n;
    int rv = findR(a, b, check, 2 * k + 1, (l + r) / 2, r);
    if (rv != -1)
      return rv;
    return findR(a, b, check, 2 * k, l, (l + r) / 2);
  }

  template <typename C> int findL(int a, int b, C &check) {
    return findL(a, b, check, 1, 0, n);
  }
  template <typename C> int findL(int a, int b, C &check, int k, int l, int r) {
    if (!check(node.at(k)) || r <= a || b <= l)
      return -1;
    if (k >= n)
      return k - n;
    int lv = findL(a, b, check, 2 * k, l, (l + r) / 2);
    if (lv != -1)
      return lv;
    return findL(a, b, check, 2 * k + 1, (l + r) / 2, r);
  }
};

int main() {

  // cin.tie(0);
  // ios::sync_with_stdio(false);
  cout << fixed << setprecision(12);

  int N, Q;
  cin >> N >> Q;
  VI c(N);
  cin >> c;

  VI lastap(N, N + 5);

  REP(i, N) { c.at(i)--; }

  vector<str> vq;
  VI ans(Q);

  REP(i, Q) {
    int l, r;
    cin >> l >> r;
    vq.EB(--l, --r, i);
  }

  sort(ALL(vq), [](auto a, auto b) { return a.r < b.r; });

  int R = -1;
  SegmentTree<int> seg(N + 10, 0, [](int a, int b) { return a + b; });

  REP(q, Q) {
    if (R < vq.at(q).r) {
      for (int i = R + 1; i <= vq.at(q).r; ++i) {
        seg.add(lastap.at(c.at(i)), -1);
        lastap.at(c.at(i)) = i;
        seg.add(lastap.at(c.at(i)), 1);
      }
    }
    int res = seg.query(vq.at(q).l, vq.at(q).r + 1);
    ans.at(vq.at(q).q) = res;
  }
  REP(i, Q) COUT(ans.at(i));

  return 0;
}


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

// conversion
//------------------------------------------
inline int toInt(string s) {
  int v;
  istringstream sin(s);
  sin >> v;
  return v;
}
template <class T> inline string toString(T x) {
  ostringstream sout;
  sout << x;
  return sout.str();
}

// math
//-------------------------------------------
template <class T> inline T sqr(T x) { return x * x; }

// typedef
//------------------------------------------
typedef long long LL;
typedef pair<int, int> PII;
typedef pair<LL, LL> PLL;
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<LL> VLL;
typedef vector<VLL> VVLL;
typedef vector<bool> VB;
typedef vector<VB> VVB;
typedef vector<double> VD;
typedef vector<VD> VVD;
typedef vector<string> VS;
typedef vector<VS> VVS;
typedef vector<char> VC;
typedef vector<VC> VVC;
typedef vector<PII> VPII;
typedef vector<PLL> VPLL;
typedef priority_queue<int> PQGI; // 大きい順
typedef priority_queue<int, VI, greater<int>> PQLI;
typedef priority_queue<PII> PQGP;
typedef priority_queue<PII, VPII, greater<int>> PQLP;

// container util
//------------------------------------------
#define ALL(a) (a).begin(), (a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define EB emplace_back
#define PB push_back
#define PF push_front
#define POB pop_back
#define POF pop_front
#define MP make_pair
#define SZ(a) int((a).size())
#define SQ(a) ((a) * (a))
#define EACH(i, c)                                                             \
  for (typeof((c).begin()) i = (c).begin(); i != (c).end(); ++i)
#define EXIST(s, e) ((s).find(e) != (s).end())
#define SORT(c) sort((c).begin(), (c).end())
#define SORTR(c) sort((c).rbegin(), (c).rend())
#define LB lower_bound
#define UB upper_bound
#define NEXP next_permutation
#define FI first
#define SE second
#define Vmin(a) *min_element((a).begin(), (a).end())
#define Vmax(a) *max_element((a).begin(), (a).end())

// repetition
//------------------------------------------
#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define REP(i, n) FOR(i, 0, n)
#define FORR(i, a, b) for (int i = (b - 1); i >= (a); i--)
#define REPR(i, n) FORR(i, 0, n)
#define CFOR(i, a, b) for (int i = (a); i <= (b); ++i)
#define CREP(i, n) CFOR(i, 0, n)
#define CFORR(i, a, b) for (int i = (b); i >= (a); i--)
#define CREPR(i, n) CFORR(i, 0, n)
#define BFOR(bit, a, b) for (int bit = (a); bit < (1 << (b)); ++bit)
#define BREP(bit, n) BFOR(bit, 0, n)

// constant
//--------------------------------------------
const double EPS = 1e-10;
const double PI = acos(-1.0);
const int INF = INT_MAX / 2;
const LL LINF = LLONG_MAX / 3;
const int RINF = INT_MIN / 2;
const LL RLINF = LLONG_MIN / 3;
const LL MOD = 1e9 + 7;
const LL MODD = 998244353;
const int MAX = 510000;

inline bool Eq(double a, double b) { return fabs(b - a) < EPS; }

// other
//-------------------------------------------
template <class T> bool chmax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> bool chmin(T &a, const T &b) {
  if (b < a) {
    a = b;
    return 1;
  }
  return 0;
}

#define COUT(x) cout << (x) << endl
#define COUT2(x, y) cout << (x) << " " << (y) << endl
#define COUT3(x, y, z) cout << (x) << " " << (y) << " " << (z) << endl
#define PR(x) cout << (x)
#define ENDL cout << endl
#define SPACE cout << " "
#define BC(x) __builtin_popcountll(x)

VI dx = {1, 0, -1, 0, 1, 1, -1, -1};
VI dy = {0, 1, 0, -1, 1, -1, 1, -1};

LL Gcd(LL a, LL b) { return __gcd(a, b); }
LL Lcm(LL a, LL b) { return a / Gcd(a, b) * b; }

LL ModPow(LL A, LL N, LL M) {
  LL res = 1;
  while (N > 0) {
    if (N & 1)
      res = res * A % M;
    A = A * A % M;
    N >>= 1;
  }
  return res;
}

template <typename T1, typename T2>
istream &operator>>(istream &is, pair<T1, T2> &p) {
  is >> p.first >> p.second;
  return is;
}

template <typename T1, typename T2>
ostream &operator<<(ostream &os, const pair<T1, T2> &p) {
  os << p.first << " " << p.second;
  return os;
}

template <typename T> istream &operator>>(istream &is, vector<T> &v) {
  for (T &in : v)
    is >> in;
  return is;
}

template <typename T> ostream &operator<<(ostream &os, const vector<T> &v) {
  for (int i = 0; i < (int)v.size(); i++) {
    os << v[i] << (i + 1 != v.size() ? " " : "");
  }
  return os;
}

template <typename T> vector<T> make_v(size_t a, T b) {
  return vector<T>(a, b);
}
template <typename... Ts> auto make_v(size_t a, Ts... ts) {
  return vector<decltype(make_v(ts...))>(a, make_v(ts...));
}

struct str {
  int l, r, q;
  str(int l, int r, int q) : l(l), r(r), q(q) {}
};

template <typename T> struct SegmentTree {
  using OP = function<T(T, T)>;

  int n;
  vector<T> node;
  T t;
  OP op;

  SegmentTree(int n_, T t, OP op) : t(t), op(op) {
    n = 1;
    while (n < n_)
      n <<= 1;
    node.assign(2 * n, t);
  }

  void init(int n_) {
    n = 1;
    while (n < n_)
      n <<= 1;
    node.assign(2 * n, t);
  }

  void set(int k, T x) { node.at(k + n) = x; }

  void build() {
    for (int k = n - 1; k > 0; k--) {
      node.at(k) = op(node.at(2 * k), node.at(2 * k + 1));
    }
  }

  void update(int k, T x) {
    k += n;
    node.at(k) = x;
    while (k >>= 1) {
      node.at(k) = op(node.at(2 * k), node.at(2 * k + 1));
    }
  }

  void update(int l, int r, T x) { FOR(k, l, r) update(k, x); }

  T at(int k) { return node.at(k + n); }

  void add(int k, T a) {
    T x = at(k) + a;
    update(k, x);
  }

  T query(int a, int b) {
    T L = t, R = t;
    for (a += n, b += n; a < b; a >>= 1, b >>= 1) {
      if (a & 1)
        L = op(L, node.at(a++));
      if (b & 1)
        R = op(node.at(--b), R);
    }
    return op(L, R);
  }

  template <typename C> int findR(int a, int b, C &check) {
    return findR(a, b, check, 1, 0, n);
  }
  template <typename C> int findR(int a, int b, C &check, int k, int l, int r) {
    if (!check(node.at(k)) || r <= a || b <= l)
      return -1;
    if (k >= n)
      return k - n;
    int rv = findR(a, b, check, 2 * k + 1, (l + r) / 2, r);
    if (rv != -1)
      return rv;
    return findR(a, b, check, 2 * k, l, (l + r) / 2);
  }

  template <typename C> int findL(int a, int b, C &check) {
    return findL(a, b, check, 1, 0, n);
  }
  template <typename C> int findL(int a, int b, C &check, int k, int l, int r) {
    if (!check(node.at(k)) || r <= a || b <= l)
      return -1;
    if (k >= n)
      return k - n;
    int lv = findL(a, b, check, 2 * k, l, (l + r) / 2);
    if (lv != -1)
      return lv;
    return findL(a, b, check, 2 * k + 1, (l + r) / 2, r);
  }
};

int main() {

  // cin.tie(0);
  // ios::sync_with_stdio(false);
  cout << fixed << setprecision(12);

  int N, Q;
  cin >> N >> Q;
  VI c(N);
  cin >> c;

  VI lastap(N, N + 5);

  REP(i, N) { c.at(i)--; }

  vector<str> vq;
  VI ans(Q);

  REP(i, Q) {
    int l, r;
    cin >> l >> r;
    vq.EB(--l, --r, i);
  }

  sort(ALL(vq), [](auto a, auto b) { return a.r < b.r; });

  int R = -1;
  SegmentTree<int> seg(N + 10, 0, [](int a, int b) { return a + b; });

  REP(q, Q) {
    if (R < vq.at(q).r) {
      for (int i = R + 1; i <= vq.at(q).r; ++i) {
        seg.add(lastap.at(c.at(i)), -1);
        lastap.at(c.at(i)) = i;
        seg.add(lastap.at(c.at(i)), 1);
      }
      R = vq.at(q).r;
    }
    int res = seg.query(vq.at(q).l, vq.at(q).r + 1);
    ans.at(vq.at(q).q) = res;
  }
  REP(i, Q) COUT(ans.at(i));

  return 0;
}