Language: C++

#line 1 "main.cpp"

/**
 * @title Template
 */

#pragma GCC target("avx2)
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#include <iostream>
#include <algorithm>
#include <utility>
#include <numeric>
#include <vector>
#include <array>

#line 2 "/Users/kodamankod/Desktop/Programming/Library/other/chmin_chmax.cpp"

template <class T, class U>
constexpr bool chmin(T &lhs, const U &rhs) {
  if (lhs > rhs) { 
    lhs = rhs; 
    return true; 
  }
  return false;
}

template <class T, class U>
constexpr bool chmax(T &lhs, const U &rhs) {
  if (lhs < rhs) { 
    lhs = rhs; 
    return true; 
  }
  return false;
}

/**
 * @title Chmin/Chmax
 */
#line 2 "/Users/kodamankod/Desktop/Programming/Library/other/range.cpp"

#line 4 "/Users/kodamankod/Desktop/Programming/Library/other/range.cpp"

class range {
public:
  class iterator {
  private:
    int64_t M_position;

  public:
    constexpr iterator(int64_t position) noexcept: M_position(position) { }
    constexpr void operator ++ () noexcept { ++M_position; }
    constexpr bool operator != (iterator other) const noexcept { return M_position != other.M_position; }
    constexpr int64_t operator * () const noexcept { return M_position; }

  };

  class reverse_iterator {
  private:
    int64_t M_position;
  
  public:
    constexpr reverse_iterator(int64_t position) noexcept: M_position(position) { }
    constexpr void operator ++ () noexcept { --M_position; }
    constexpr bool operator != (reverse_iterator other) const noexcept { return M_position != other.M_position; }
    constexpr int64_t operator * () const noexcept { return M_position; }

  };
  
private:
  const iterator M_first, M_last;

public:
  constexpr range(int64_t first, int64_t last) noexcept: M_first(first), M_last(std::max(first, last)) { }
  constexpr iterator begin() const noexcept { return M_first; }
  constexpr iterator end() const noexcept { return M_last; }
  constexpr reverse_iterator rbegin() const noexcept { return reverse_iterator(*M_last - 1); } 
  constexpr reverse_iterator rend() const noexcept { return reverse_iterator(*M_first - 1); } 

};

/**
 * @title Range
 */
#line 2 "/Users/kodamankod/Desktop/Programming/Library/other/rev.cpp"

#include <type_traits>
#include <iterator>
#line 6 "/Users/kodamankod/Desktop/Programming/Library/other/rev.cpp"

template <class T>
class rev_impl {
public:
  using iterator = typename std::decay<T>::type::reverse_iterator;

private:
  const iterator M_begin;
  const iterator M_end;

public:
  constexpr rev_impl(T &&cont) noexcept: M_begin(std::rbegin(cont)), M_end(std::rend(cont)) { }
  constexpr iterator begin() const noexcept { return M_begin; }
  constexpr iterator end() const noexcept { return M_end; }

};

template <class T>
constexpr decltype(auto) rev(T &&cont) {
  return rev_impl<T>(std::forward<T>(cont));
}

/**
 * @title Reverser
 */
#line 2 "/Users/kodamankod/Desktop/Programming/Library/container/fenwick_tree.cpp"

#line 2 "/Users/kodamankod/Desktop/Programming/Library/other/bit_operation.cpp"

#include <cstddef>
#include <cstdint>

constexpr size_t bit_ppc(const uint64_t x) {
  return __builtin_popcountll(x);
}

constexpr size_t bit_ctzr(const uint64_t x) {
  return x == 0 ? 64 : __builtin_ctzll(x);
}

constexpr size_t bit_ctzl(const uint64_t x) {
  return x == 0 ? 64 : __builtin_clzll(x);
}

constexpr size_t bit_width(const uint64_t x) { 
  return 64 - bit_ctzl(x);
}

constexpr uint64_t bit_msb(const uint64_t x) {
  return x == 0 ? 0 : uint64_t(1) << (bit_width(x) - 1);
}

constexpr uint64_t bit_lsb(const uint64_t x) {
  return x & (-x);
}

constexpr uint64_t bit_cover(const uint64_t x) {
  return x == 0 ? 0 : bit_msb(2 * x - 1);
}

constexpr uint64_t bit_rev(uint64_t x) {
  x = ((x >> 1) & 0x5555555555555555) | ((x & 0x5555555555555555) << 1);
  x = ((x >> 2) & 0x3333333333333333) | ((x & 0x3333333333333333) << 2);
  x = ((x >> 4) & 0x0F0F0F0F0F0F0F0F) | ((x & 0x0F0F0F0F0F0F0F0F) << 4);
  x = ((x >> 8) & 0x00FF00FF00FF00FF) | ((x & 0x00FF00FF00FF00FF) << 8);
  x = ((x >> 16) & 0x0000FFFF0000FFFF) | ((x & 0x0000FFFF0000FFFF) << 16);
  x = (x >> 32) | (x << 32);
  return x;
}

/**
 * @title Bit Operations
 */
#line 6 "/Users/kodamankod/Desktop/Programming/Library/container/fenwick_tree.cpp"

template <class T>
class fenwick_tree {
public:
  using value_type = T;
  using size_type = size_t;

private:
  std::vector<value_type> M_tree;

public:
  fenwick_tree() = default;
  explicit fenwick_tree(size_type size) { initialize(size); }

  void initialize(size_type size) {
    M_tree.assign(size + 1, value_type{});
  }

  void add(size_type index, const value_type& x) {
    ++index;
    while (index <= size()) {
      M_tree[index] += x;
      index += bit_lsb(index);
    }
  }

  value_type get(size_type index) const {
    ++index;
    value_type res{};
    while (index > 0) {
      res += M_tree[index];
      index -= bit_lsb(index);
    }
    return res;
  }
  value_type fold(size_type l, size_type r) const {
    if (l == 0 && r == 0) return value_type{};
    if (l == 0) return get(r - 1);
    return get(r - 1) - get(l - 1);
  }

  size_type size() const {
    return M_tree.size() - 1;
  }

};

/**
 * @title Fenwick Tree
 */
#line 2 "/Users/kodamankod/Desktop/Programming/Library/other/fast_io.cpp"

#line 5 "/Users/kodamankod/Desktop/Programming/Library/other/fast_io.cpp"
#include <cstring>
#line 7 "/Users/kodamankod/Desktop/Programming/Library/other/fast_io.cpp"

namespace fast_io {
  static constexpr size_t buf_size = 1 << 18;
  static constexpr size_t buf_margin = 1;
  static constexpr size_t block_size = 10000;
  static constexpr size_t integer_size = 20;

  static char inbuf[buf_size + buf_margin] = {};
  static char outbuf[buf_size + buf_margin] = {};
  static char block_str[block_size * 4 + buf_margin] = {};

  static constexpr uint64_t power10[] = {
    1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000,
    1000000000, 10000000000, 100000000000, 1000000000000, 10000000000000,
    100000000000000, 1000000000000000, 10000000000000000, 100000000000000000,
    1000000000000000000, 10000000000000000000u
  };

  class scanner {
  private:
    size_t M_in_pos = 0, M_in_end = buf_size;

    void M_load() { 
      M_in_end = fread(inbuf, 1, buf_size, stdin); 
      inbuf[M_in_end] = '\0';  
    }
    void M_reload() {
      size_t length = M_in_end - M_in_pos;
      memmove(inbuf, inbuf + M_in_pos, length);
      M_in_end = length + fread(inbuf + length, 1, buf_size - length, stdin);
      inbuf[M_in_end] = '\0';
      M_in_pos = 0;
    }

    void M_ignore_space() {
      while (inbuf[M_in_pos] <= ' ') {
        if (__builtin_expect(++M_in_pos == M_in_end, 0)) M_reload();
      }
    }

    char M_next() { return inbuf[M_in_pos++]; }
    char M_next_nonspace() {
      M_ignore_space();
      return inbuf[M_in_pos++];
    }

  public:
    scanner() { M_load(); }
    
    void scan(char &c) { c = M_next_nonspace(); }
    void scan(std::string &s) {
      M_ignore_space();
      s = "";
      do {
        size_t start = M_in_pos;
        while (inbuf[M_in_pos] > ' ') ++M_in_pos;
        s += std::string(inbuf + start, inbuf + M_in_pos);
        if (inbuf[M_in_pos] != '\0') break;
        M_reload();
      } while (true);
    }

    template <class T>
    typename std::enable_if<std::is_integral<T>::value, void>::type scan(T &x) {
      char c = M_next_nonspace();
      if (__builtin_expect(M_in_pos + integer_size >= M_in_end, 0)) M_reload();
      bool n = false;
      if (c == '-') n = true, x = 0;
      else x = c & 15;
      while ((c = M_next()) >= '0') x = x * 10 + (c & 15);
      if (n) x = -x;
    }

    template <class T, class... Args>
    void scan(T &x, Args&... args) {
      scan(x); scan(args...);
    }

    template <class T>
    scanner& operator >> (T &x) {
      scan(x); return *this;
    }

  };

  class printer {
  private:
    size_t M_out_pos = 0;

    void M_flush() {
      fwrite(outbuf, 1, M_out_pos, stdout);
      M_out_pos = 0;
    }

    void M_precompute() {
      for (size_t i = 0; i < block_size; ++i) {
        size_t j = 4, k = i;
        while (j--) {
          block_str[i * 4 + j] = k % 10 + '0';
          k /= 10;
        }
      }
    }

    static constexpr size_t S_integer_digits(uint64_t n) {
      if (n >= power10[10]) {
        if (n >= power10[19]) return 20;
        if (n >= power10[18]) return 19;
        if (n >= power10[17]) return 18;
        if (n >= power10[16]) return 17;
        if (n >= power10[15]) return 16;
        if (n >= power10[14]) return 15;
        if (n >= power10[13]) return 14;
        if (n >= power10[12]) return 13;
        if (n >= power10[11]) return 12;
        return 11;
      }
      else {
        if (n >= power10[9]) return 10;
        if (n >= power10[8]) return 9;
        if (n >= power10[7]) return 8;
        if (n >= power10[6]) return 7;
        if (n >= power10[5]) return 6;
        if (n >= power10[4]) return 5;
        if (n >= power10[3]) return 4;
        if (n >= power10[2]) return 3;
        if (n >= power10[1]) return 2;
        return 1;
      }
    }

  public:
    printer() { M_precompute(); }
    ~printer() { M_flush(); }

    void print(char c) { 
      outbuf[M_out_pos++] = c;
      if (__builtin_expect(M_out_pos == buf_size, 0)) M_flush();
    }
    void print(const char *s) {
      while (*s != 0) {
        outbuf[M_out_pos++] = *s++;
        if (M_out_pos == buf_size) M_flush();
      }
    }
    void print(const std::string &s) {
      for (auto c: s) {
        outbuf[M_out_pos++] = c;
        if (M_out_pos == buf_size) M_flush();
      }
    }
    
    template <class T>
    typename std::enable_if<std::is_integral<T>::value, void>::type print(T x) {
      if (__builtin_expect(M_out_pos + integer_size >= buf_size, 0)) M_flush();
      if (x < 0) print('-'), x = -x;
      size_t digit = S_integer_digits(x);
      size_t len = digit;
      while (len >= 4) {
        len -= 4;
        memcpy(outbuf + M_out_pos + len, block_str + (x % block_size) * 4, 4);
        x /= 10000;
      }
      memcpy(outbuf + M_out_pos, block_str + x * 4 + 4 - len, len);
      M_out_pos += digit;
    }

    template <class T, class... Args>
    void print(const T &x, const Args&... args) {
      print(x); print(' '); print(args...);
    }

    template <class... Args>
    void println(const Args&... args) {
      print(args...); print('\n');
    }

    template <class T>
    printer& operator << (const T &x) {
      print(x); return *this;
    }

  };

};

/**
 * @title Fast Input/Output
 */
#line 18 "main.cpp"

using i32 = int32_t;
using i64 = int64_t;
using u32 = uint32_t;
using u64 = uint64_t;

constexpr i32 inf32 = (i32(1) << 30) - 1;
constexpr i64 inf64 = (i64(1) << 62) - 1;

fast_io::scanner cin;
fast_io::printer cout;

int main() {
  i32 N, Q;
  cin >> N >> Q;
  std::vector<i32> A(N);
  for (auto &x: A) {
    cin >> x;
    --x;
  }
  std::vector<i32> L(Q), R(Q);
  for (auto i: range(0, Q)) {
    cin >> L[i] >> R[i];
    --L[i];
  }
  std::vector<i32> ans(Q);
  std::vector<i32> cur(N, N);
  fenwick_tree<i32> fen(N + 1);
  std::vector<std::vector<i32>> Qs(N);
  for (auto i: range(0, Q)) {
    Qs[R[i] - 1].push_back(i);
  }
  for (auto i: range(0, N)) {
    fen.add(cur[A[i]], -1);
    cur[A[i]] = i;
    fen.add(cur[A[i]], 1);
    for (auto k: Qs[i]) {
      ans[k] = fen.fold(L[k], R[k]);
    }
  }
  for (auto x: ans) {
    cout << x << '\n';
  }
  return 0;
}


Compiler output:
main.cpp:6:20: warning: missing terminating " character
main.cpp:6:20: error: missing terminating " character
main.cpp:6:26: warning: '#pragma GCC option' is not a string [-Wpragmas]
main.cpp:6:26: warning: '#pragma GCC option' is not a string [-Wpragmas]