Problem p02599 (C++)

Buggy submission (status: Runtime Error):
#include <algorithm>
#include <array>
#include <cassert>
#include <cmath>
#include <complex>
#include <cstdint>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

using namespace std;

#ifdef _DEBUG
#define DUMP(x) std::cerr << (#x) << " = " << (x) << "\n"
#else
#define DUMP(x)
#endif
#define REP(i, a, b) for (int i = (int)(a); i < (int)(b); ++i)
#define EREP(i, a, b) for (int i = (int)(a); i <= (int)(b); ++i)
#define RREP(i, a, b) for (int i = (int)(a)-1; i >= (int)(b); --i)
#define rep(i, n) REP(i, 0, n)
#define erep(i, n) EREP(i, 0, n)
#define rrep(i, n) RREP(i, n, 0)
#define ALL(r) (r).begin(), (r).end()
#define pb push_back
#define eb emplace_back
#define fi first
#define se second

template <typename T> ostream &operator<<(ostream &os, const vector<T> &v) {
  os << "{";
  rep(i, v.size()) os << v[i] << (i == (int)v.size() - 1 ? "" : ", ");
  os << "}";
  return os;
}
template <typename T, typename U>
ostream &operator<<(ostream &os, const pair<T, U> &p) {
  return (os << "(" << p.first << ", " << p.second << ")");
}
template <typename T, typename U>
ostream &operator<<(ostream &os, const map<T, U> &m) {
  bool first = true;
  os << "{";
  for (const auto &e : m) {
    if (!first)
      os << ", ";
    os << "{" << e.first << ": " << e.second << "}";
    first = false;
  }
  os << "}";
  return os;
}
template <typename T> ostream &operator<<(ostream &os, const set<T> &s) {
  os << "{";
  bool first = true;
  for (const auto &e : s) {
    if (!first)
      os << ", ";
    os << e;
    first = false;
  }
  os << "}";
  return os;
}
template <typename T> ostream &operator<<(ostream &os, const multiset<T> &s) {
  os << "{";
  bool first = true;
  for (const auto &e : s) {
    if (!first)
      os << ", ";
    os << e;
    first = false;
  }
  os << "}";
  return os;
}
template <typename T> T dup(T x, T y) { return (x + y - 1) / y; };
template <typename A, size_t N, typename T>
inline void arrayFill(A (&array)[N], const T &val) {
  std::fill((T *)array, (T *)(array + N), val);
}
template <class T> inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
template <class T> inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
struct in {
  const size_t n = 0;
  in() = default;
  in(size_t n) : n(n){};
  template <typename T> operator T() {
    T ret;
    cin >> ret;
    return ret;
  }
  template <typename T> operator vector<T>() {
    assert(n != 0);
    vector<T> ret(n);
    for (T &x : ret) {
      T tmp = in();
      x = tmp;
    }
    return ret;
  }
  template <typename T, typename U> operator pair<T, U>() {
    pair<T, U> ret;
    ret.first = in();
    ret.second = in();
    return ret;
  }
};

namespace fiore::impl {
template <typename T> inline void out_impl(const T &x, char end_char) {
  std::cout << x << end_char;
}
template <typename T> inline void out_impl(const vector<T> &x, char end_char) {
  bool first = true;
  for (const auto &e : x) {
    if (!first)
      std::cout << ' ';
    std::cout << e;
    first = false;
  }
  std::cout << end_char;
}
} // namespace fiore::impl
template <typename T> inline void out(const T &x) {
  fiore::impl::out_impl(x, '\n');
};
template <typename T, typename U, typename... Args>
inline void out(const T &x, const U &y, const Args &...args) {
  fiore::impl::out_impl(x, ' ');
  out(y, args...);
}

using ll = int64_t;
using vint = vector<int32_t>;
using vvint = vector<vint>;
using vll = vector<ll>;
using vvll = vector<vll>;
using vstr = vector<string>;
using pint = pair<int32_t, int32_t>;
using vpint = vector<pint>;
using pll = pair<ll, ll>;
using vpll = vector<pll>;
using setint = set<int32_t>;
using qint = queue<int32_t>;
using qpint = queue<pint>;

constexpr std::int32_t INF = 1001001001;
constexpr std::int64_t LINF = 1001001001001001001;

template <typename T> class SegmentTree {
  using F = function<T(T, T)>;
  int n;
  const F f;
  const T ti;
  vector<T> dat;

public:
  SegmentTree(const int n_, const F f, const T ti,
              const vector<T> &v = vector<T>())
      : f(f), ti(ti) {
    if (n_ == (int)v.size())
      build(n_, v);
    else
      init(n_);
  }

  // update k_th element to x
  void set_val(int k, const T x) {
    dat[k += n] = x;
    while (k >>= 1)
      dat[k] = f(dat[(k << 1) | 0], dat[(k << 1) | 1]);
  }

  // execute a query against [a, b)
  T query(const int a, const int b) {
    if (a >= b)
      return ti;
    T vl = ti, vr = ti;
    for (int l = a + n, r = b + n; l < r; l >>= 1, r >>= 1) {
      if (l & 1)
        vl = f(vl, dat[l++]);
      if (r & 1)
        vr = f(dat[--r], vr);
    }
    return f(vl, vr);
  }

  // get k_th element
  T operator[](const int k) const { return dat[k + n]; }

private:
  void init(const int n_) {
    n = 1;
    while (n < n_)
      n <<= 1;
    dat.assign(n << 1, ti);
  }

  void build(const int n_, const vector<T> &v) {
    init(n_);
    for (int i = 0; i < n_; i++)
      dat[n + i] = v[i];
    for (int i = n - 1; i; i--)
      dat[i] = f(dat[(i << 1) | 0], dat[(i << 1) | 1]);
  }
};

void Main() {
  int n = in(), q = in();
  vint c = in(n);
  vvint pos(n);
  rep(i, n) { pos[c[i]].pb(i); }
  vector<tuple<int, int, int>> v;
  v.reserve(q);
  rep(i, n) {
    rep(j, pos[i].size()) {
      if (j == pos[i].size() - 1) {
        v.eb(n + 1, -1, pos[i][j]);
      } else
        v.eb(pos[i][j + 1], -1, pos[i][j]);
    }
  }
  rep(i, q) {
    int l = in(), r = in();
    --l, --r;
    v.eb(r, i, l);
  }
  sort(ALL(v));

  SegmentTree<int> seg(n + 2, plus<int>(), 0);
  vint ans(q);

  DUMP(v.size());

  for (auto [r, type, l] : v) {
    DUMP(l);
    DUMP(r);
    DUMP(type);
    if (type == -1) {
      seg.set_val(l, seg[l] + 1);
    } else {
      ans[type] = (r + 1 - l) - seg.query(l, r + 1);
    }
  }
  for (auto e : ans)
    out(e);
}

signed main() {
  std::cin.tie(nullptr);
  std::ios_base::sync_with_stdio(false);
  std::cout << std::fixed << std::setprecision(15);
  Main();
  return 0;
}

Fixed submission:
#include <algorithm>
#include <array>
#include <cassert>
#include <cmath>
#include <complex>
#include <cstdint>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

using namespace std;

#ifdef _DEBUG
#define DUMP(x) std::cerr << (#x) << " = " << (x) << "\n"
#else
#define DUMP(x)
#endif
#define REP(i, a, b) for (int i = (int)(a); i < (int)(b); ++i)
#define EREP(i, a, b) for (int i = (int)(a); i <= (int)(b); ++i)
#define RREP(i, a, b) for (int i = (int)(a)-1; i >= (int)(b); --i)
#define rep(i, n) REP(i, 0, n)
#define erep(i, n) EREP(i, 0, n)
#define rrep(i, n) RREP(i, n, 0)
#define ALL(r) (r).begin(), (r).end()
#define pb push_back
#define eb emplace_back
#define fi first
#define se second

template <typename T> ostream &operator<<(ostream &os, const vector<T> &v) {
  os << "{";
  rep(i, v.size()) os << v[i] << (i == (int)v.size() - 1 ? "" : ", ");
  os << "}";
  return os;
}
template <typename T, typename U>
ostream &operator<<(ostream &os, const pair<T, U> &p) {
  return (os << "(" << p.first << ", " << p.second << ")");
}
template <typename T, typename U>
ostream &operator<<(ostream &os, const map<T, U> &m) {
  bool first = true;
  os << "{";
  for (const auto &e : m) {
    if (!first)
      os << ", ";
    os << "{" << e.first << ": " << e.second << "}";
    first = false;
  }
  os << "}";
  return os;
}
template <typename T> ostream &operator<<(ostream &os, const set<T> &s) {
  os << "{";
  bool first = true;
  for (const auto &e : s) {
    if (!first)
      os << ", ";
    os << e;
    first = false;
  }
  os << "}";
  return os;
}
template <typename T> ostream &operator<<(ostream &os, const multiset<T> &s) {
  os << "{";
  bool first = true;
  for (const auto &e : s) {
    if (!first)
      os << ", ";
    os << e;
    first = false;
  }
  os << "}";
  return os;
}
template <typename T> T dup(T x, T y) { return (x + y - 1) / y; };
template <typename A, size_t N, typename T>
inline void arrayFill(A (&array)[N], const T &val) {
  std::fill((T *)array, (T *)(array + N), val);
}
template <class T> inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
template <class T> inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
struct in {
  const size_t n = 0;
  in() = default;
  in(size_t n) : n(n){};
  template <typename T> operator T() {
    T ret;
    cin >> ret;
    return ret;
  }
  template <typename T> operator vector<T>() {
    assert(n != 0);
    vector<T> ret(n);
    for (T &x : ret) {
      T tmp = in();
      x = tmp;
    }
    return ret;
  }
  template <typename T, typename U> operator pair<T, U>() {
    pair<T, U> ret;
    ret.first = in();
    ret.second = in();
    return ret;
  }
};

namespace fiore::impl {
template <typename T> inline void out_impl(const T &x, char end_char) {
  std::cout << x << end_char;
}
template <typename T> inline void out_impl(const vector<T> &x, char end_char) {
  bool first = true;
  for (const auto &e : x) {
    if (!first)
      std::cout << ' ';
    std::cout << e;
    first = false;
  }
  std::cout << end_char;
}
} // namespace fiore::impl
template <typename T> inline void out(const T &x) {
  fiore::impl::out_impl(x, '\n');
};
template <typename T, typename U, typename... Args>
inline void out(const T &x, const U &y, const Args &...args) {
  fiore::impl::out_impl(x, ' ');
  out(y, args...);
}

using ll = int64_t;
using vint = vector<int32_t>;
using vvint = vector<vint>;
using vll = vector<ll>;
using vvll = vector<vll>;
using vstr = vector<string>;
using pint = pair<int32_t, int32_t>;
using vpint = vector<pint>;
using pll = pair<ll, ll>;
using vpll = vector<pll>;
using setint = set<int32_t>;
using qint = queue<int32_t>;
using qpint = queue<pint>;

constexpr std::int32_t INF = 1001001001;
constexpr std::int64_t LINF = 1001001001001001001;

template <typename T> class SegmentTree {
  using F = function<T(T, T)>;
  int n;
  const F f;
  const T ti;
  vector<T> dat;

public:
  SegmentTree(const int n_, const F f, const T ti,
              const vector<T> &v = vector<T>())
      : f(f), ti(ti) {
    if (n_ == (int)v.size())
      build(n_, v);
    else
      init(n_);
  }

  // update k_th element to x
  void set_val(int k, const T x) {
    dat[k += n] = x;
    while (k >>= 1)
      dat[k] = f(dat[(k << 1) | 0], dat[(k << 1) | 1]);
  }

  // execute a query against [a, b)
  T query(const int a, const int b) {
    if (a >= b)
      return ti;
    T vl = ti, vr = ti;
    for (int l = a + n, r = b + n; l < r; l >>= 1, r >>= 1) {
      if (l & 1)
        vl = f(vl, dat[l++]);
      if (r & 1)
        vr = f(dat[--r], vr);
    }
    return f(vl, vr);
  }

  // get k_th element
  T operator[](const int k) const { return dat[k + n]; }

private:
  void init(const int n_) {
    n = 1;
    while (n < n_)
      n <<= 1;
    dat.assign(n << 1, ti);
  }

  void build(const int n_, const vector<T> &v) {
    init(n_);
    for (int i = 0; i < n_; i++)
      dat[n + i] = v[i];
    for (int i = n - 1; i; i--)
      dat[i] = f(dat[(i << 1) | 0], dat[(i << 1) | 1]);
  }
};

void Main() {
  int n = in(), q = in();
  vint c = in(n);
  vvint pos(n);
  rep(i, n) { pos[c[i] - 1].pb(i); }
  vector<tuple<int, int, int>> v;
  v.reserve(q);
  rep(i, n) {
    rep(j, pos[i].size()) {
      if (j == pos[i].size() - 1) {
        v.eb(n + 1, -1, pos[i][j]);
      } else
        v.eb(pos[i][j + 1], -1, pos[i][j]);
    }
  }
  rep(i, q) {
    int l = in(), r = in();
    --l, --r;
    v.eb(r, i, l);
  }
  sort(ALL(v));

  SegmentTree<int> seg(n + 2, plus<int>(), 0);
  vint ans(q);

  DUMP(v.size());

  for (auto [r, type, l] : v) {
    DUMP(l);
    DUMP(r);
    DUMP(type);
    if (type == -1) {
      seg.set_val(l, seg[l] + 1);
    } else {
      ans[type] = (r + 1 - l) - seg.query(l, r + 1);
    }
  }
  for (auto e : ans)
    out(e);
}

signed main() {
  std::cin.tie(nullptr);
  std::ios_base::sync_with_stdio(false);
  std::cout << std::fixed << std::setprecision(15);
  Main();
  return 0;
}