Language: C++

#include <memory.h>

#include <algorithm>
#include <bitset>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <deque>
#include <iomanip>
#include <iostream>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <utility>
#include <vector>

using namespace std;

#define MOD 1000000007
#define INIT -1

int main()
{
   int n, d, a;
   cin >> n >> d >> a;
   vector<pair<long long int, long long int>> v;
   for (int i = 0; i < n; i++)
   {
      int x, h;
      cin >> x >> h;
      v.push_back(make_pair(x, h));
   }
   sort(v.begin(), v.end());
   long long int ans = 0;
   long long int cnt[200000] = {};
   for (int i = 0; i < n; i++)
   {
      if (i > 0)
         cnt[i] += cnt[i - 1];
      long long int x = v[i].first;
      long long int h = v[i].second;
      long long int need = h / a;
      if (h % a > 0)
         need++;
      need -= cnt[i];
      cnt[i] += need;
      int idx = upper_bound(v.begin(), v.end(), make_pair(x + 2 * d, MOD)) - v.begin();
      if (idx != v.size())
         cnt[idx] -= need;
      ans += need;
   }
   cout << ans << endl;
}

Compiler output:
In file included from /usr/include/c++/14/bits/stl_algobase.h:71,
                 from /usr/include/c++/14/algorithm:60,
                 from a.cc:3:
/usr/include/c++/14/bits/predefined_ops.h: In instantiation of 'bool __gnu_cxx::__ops::_Val_less_iter::operator()(_Value&, _Iterator) const [with _Value = const std::pair<long long int, int>; _Iterator = __gnu_cxx::__normal_iterator<std::pair<long long int, long long int>*, std::vector<std::pair<long long int, long long int> > >]':
/usr/include/c++/14/bits/stl_algo.h:1993:14:   required from '_ForwardIterator std::__upper_bound(_ForwardIterator, _ForwardIterator, const _Tp&, _Compare) [with _ForwardIterator = __gnu_cxx::__normal_iterator<pair<long long int, long long int>*, vector<pair<long long int, long long int> > >; _Tp = pair<long long int, int>; _Compare = __gnu_cxx::__ops::_Val_less_iter]'
 1993 |           if (__comp(__val, __middle))
      |               ~~~~~~^~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:2028:32:   required from '_FIter std::upper_bound(_FIter, _FIter, const _Tp&) [with _FIter = __gnu_cxx::__normal_iterator<pair<long long int, long long int>*, vector<pair<long long int, long long int> > >; _Tp = pair<long long int, int>]'
 2028 |       return std::__upper_bound(__first, __last, __val,
      |              ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
 2029 |                                 __gnu_cxx::__ops::__val_less_iter());
      |                                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
a.cc:52:28:   required from here
   52 |       int idx = upper_bound(v.begin(), v.end(), make_pair(x + 2 * d, MOD)) - v.begin();
      |                 ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/predefined_ops.h:98:22: error: no match for 'operator<' (operand types are 'const std::pair<long long int, int>' and 'std::pair<long long int, long long int>')
   98 |       { return __val < *__it; }
      |                ~~~~~~^~~~~~~
In file included from /usr/include/c++/14/bits/stl_algobase.h:67:
/usr/include/c++/14/bits/stl_iterator.h:1241:5: note: candidate: 'template<class _IteratorL, class _IteratorR, class _Container> bool __gnu_cxx::operator<(const __normal_iterator<_IteratorL, _Container>&, const __normal_iterator<_IteratorR, _Container>&)'
 1241 |     operator<(const __normal_iterator<_IteratorL, _Container>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1241:5: note:   template argument deduction/substitution failed:
/usr/include/c++/14/bits/predefined_ops.h:98:22: note:   'const std::pair<long long int, int>' is not derived from 'const __gnu_cxx::__normal_iterator<_IteratorL, _Container>'
   98 |       { return __val < *__it; }
      |                ~~~~~~^~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1249:5: note: candidate: 'template<class _Iterator, class _Container> bool __gnu_cxx::operator<(const __normal_iterator<_Iterator, _Container>&, const __normal_iterator<_Iterator, _Container>&)'
 1249 |     operator<(const __normal_iterator<_Iterator, _Container>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1249:5: note:   template argument deduction/substitution failed:
/usr/include/c++/14/bits/predefined_ops.h:98:22: note:   'const std::pair<long long int, int>' is not derived from 'const __gnu_cxx::__normal_iterator<_Iterator, _Container>'
   98 |       { return __val < *__it; }
      |                ~~~~~~^~~~~~~
In file included from /usr/include/c++/14/bits/stl_algobase.h:64:
/usr/include/c++/14/bits/stl_pair.h:1045:5: note: candidate: 'template<class _T1, class _T2> constexpr bool std::operator<(const pair<_T1, _T2>&, const pair<_T1, _T2>&)'
 1045 |     operator<(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_pair.h:1045:5: note:   template argument deduction/substitution failed:
/usr/include/c++/14/bits/predefined_ops.h:98:22: note:   deduced conflicting types for parameter '_T2' ('int' and 'long long int')
   98 |       { return __val < *__it; }
      |                ~~~~~~^~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:448:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator<(const reverse_iterator<_Iterator>&, const reverse_iterator<_Iterator>&)'
  448 |     operator<(const reverse_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:448:5: note:   template argument deduction/substitution failed:
/usr/include/c++/14/bits/predefined_ops.h:98:22: note:   'const std::pair<long long int, int>' is not derived from 'const std::reverse_iterator<_Iterator>'
   98 |       { return __val < *__it; }
      |                ~~~~~~^~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:493:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator<(const reverse_iterator<_Iterator>&, const reverse_iterator<_IteratorR>&)'
  493 |     operator<(const reverse_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:493:5: note:   template argument deduction/substitution failed:
/usr/include/c++/14/bits/predefined_ops.h:98:22: note:   'const std::pair<long long int, int>' is not derived from 'const std::reverse_iterator<_Iterator>'
   98 |       { return __val < *__it; }
      |                ~~~~~~^~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1694:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator<(const move_iterator<_IteratorL>&, const move_iterator<_IteratorR>&)'
 1694 |     operator<(const move_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1694:5: note:   template argument deduction/substitution failed:
/usr/include/c++/14/bits/predefined_ops.h:98:22: note:   'const std::pair<long long int, int>' is not derived from 'const std::move_iterator<_IteratorL>'
   98 |       { return __val < *__it; }
      |                ~~~~~~^~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1760:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator<(const move_iterator<_IteratorL>&, const move_iterator<_IteratorL>&)'
 1760 |     operator<(const move_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1760:5: note:   template argument deduction/substitution failed:
/usr/include/c++/14/bits/predefined_ops.h:98:22: note:   'const std::pair<long long int, int>' is not derived from 'const std::move_iterator<_IteratorL>'
   98 |       { return __val < *__it; }
      |                ~~~~~~^~~~~~~
In file included from /usr/include/c++/14/bits/basic_string.h:47,
                 from /usr/include/c++/14/string:54,
                 from /usr/include/c++/14/bitset:52,
                 from a.cc:4:
/usr/include/c++/14/string_view:673:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator<(basic_string_view<_CharT, _Traits>, basic_string_view<_CharT, _Traits>)'
  673 |     operator< (basic_string_view<_CharT, _Traits> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:673:5: note:   template argument deduction/substitution failed:
/usr/include/c++/14/bits/predefined_ops.h:98:22: note:   'std::pair<long long int, int>' is not derived from 'std::basic_string_view<_CharT, _Traits>'
   98 |       { return __val < *__it; }
      |                ~~~~~~^~~~~~~
/usr/include/c++/14/string_view:680:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator<(basic_string_view<_CharT, _Traits>, __type_identity_t<basic_string_view<_CharT, _Traits> >)'
  680 |     operator< (basic_string_view<_CharT, _Traits> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:680:5: note:   template argument deduction/substitution failed:
/usr/include/c++/14/bits/predefined_ops.h:98:22: note:   'std::pair<long long int, int>' is not derived from 'std::basic_string_view<_CharT, _Traits>'
   98 |       { return __val < *__it; }
      |                ~~~~~~^~~~~~~
/usr/include/c++/14/string_view:688:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator<(__type_identity_t<basic_string_view<_CharT, _Traits> >, basic_string_view<_CharT, _Traits>)'
  688 |     operator< (__type_identity_t<basic_string_view<_CharT, _Traits>> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:688:5: note:   template argument deduction/substitution failed:
/usr/include/c++/14/bits/predefined_ops.h:98:22: note:   'std::pair<long long int, long long int>' is not derived from 'std::basic_string_view<_CharT, _Traits>'
   98 |       { return __val < *__it; }
      |                ~~~~~~^~~~~~~
/usr/include/c++/14/bits/basic_string.h:3874:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator<(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3874 |     operator<(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3874:5: note:   template argument deduction/substitution failed:
/usr/include/c++/14/bits/predefined_ops.h:98:22: note:   'const std::pair<long long int, int>' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   98 |       { return __val < *__it; }
      |                ~~~~~~^~~~~~~
/usr/include/c++/14/bits/basic_string.h:3888:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator<(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, const _CharT*)'
 3888 |     operator<(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3888:5: note:   template argument deduction/substitution failed:
/usr/include/c++/14/bits/predefined_ops.h:98:22: note:   'const std::pair<long long int, int>' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   98 |       { return __val < *__it; }
      |                ~~~~~~^~~~~~~
/usr/include/c++/14/bits/basic_string.h:3901:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator<(const _CharT*, const __cxx11::basic_string<_CharT, _Tra