Language: C++

#ifndef _GLIBCXX_NO_ASSERT
#include <cassert>
#endif
#include <cctype>
#include <cerrno>
#include <cfloat>
#include <ciso646>
#include <climits>
#include <clocale>
#include <cmath>
#include <csetjmp>
#include <csignal>
#include <cstdarg>
#include <cstddef>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>

#if __cplusplus >= 201103L
#include <ccomplex>
#include <cfenv>
#include <cinttypes>
#include <cstdbool>
#include <cstdint>
#include <ctgmath>
#include <cwchar>
#include <cwctype>
#endif

// C++
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <locale>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <typeinfo>
#include <utility>
#include <valarray>
#include <vector>

#if __cplusplus >= 201103L
#include <array>
#include <atomic>
#include <chrono>
#include <condition_variable>
#include <forward_list>
#include <future>
#include <initializer_list>
#include <mutex>
#include <random>
#include <ratio>
#include <regex>
#include <scoped_allocator>
#include <system_error>
#include <thread>
#include <tuple>
#include <typeindex>
#include <type_traits>
#include <unordered_map>
#include <unordered_set>
#endif

using namespace std;

#define _GLIBCXX_DEBUG

using _loop_ll = long long;
#define REP(i,n) for(_loop_ll (i)=0; (i)<(_loop_ll)(n); (i)++)
#define FOR(i,a,b) for(_loop_ll (i)=(_loop_ll)(a); (i)<(_loop_ll)(b); (i)++)
#define FORR(i,a,b) for(_loop_ll (i)=(_loop_ll)(b)-1; (i)>=(_loop_ll)(a); (i)--)
 
#define ALL(v) (v).begin(),(v).end()
 
#define DEBUG(x) cerr<<#x<<": "<<(x)<<endl
#define DEBUG_VEC(v) cerr<<#v<<": ";REP(__i,(v).size())cerr<<((v)[__i])<<", ";cerr<<endl

using ll = long long;
using pii = pair<int,int>;
using pll = pair<ll,ll>;
using vi = vector<int>;
using vl = vector<ll>;
using vvi = vector<vi>;
using vvl = vector<vl>;

constexpr long long int MOD = 1e9 + 7;
constexpr long long int INF = 1e10;

vector<pii> interval(200010);
vi bom(200010), cum(200010);

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    
    int N, D, A;
    cin >> N >> D >> A;

    vector<pll> fox(N);
    REP(i, N){
        ll x, h;
        cin >> x >> h;
        fox[i] = make_pair(x, h);
    }
    sort(ALL(fox));

    ll x = fox[0]->first;
    auto itr = prev(upper_bound(ALL(fox), make_pair(x + 2 * D, INF)));
    int idx = distance(fox.begin(), itr);
    interval[0] = make_pair(0, idx);
    
    int j = 1;
    FOR(i, 1, N){
        ll x = fox[i]->first;
        auto itr = prev(upper_bound(ALL(fox), make_pair(x + 2 * D, INF)));
        int idx = distance(interval.begin(), itr);
        if (interval[j - 1]->second < idx){
            interval[j] = make_pair(i, idx);
            j++;
        }
    }

    int bomsum = 0;
    int prev_idx2 = 0;
    REP(i, N){
        ll h = fox[h]->second;
        auto itr1 = lower_bound(ALL(interval), make_pair(-INF, i));
        int idx1 = distance(interval.begin(), itr1);
        auto itr2 = prev(upper_bound(ALL(interval), make_pair(INF, i)));
        int idx2 = distance(interval.begin(), itr2);
        if (prev_idx2 < idx2){
            cum[idx2] = cum[idx2 - 1];
            prev_idx2 = idx2;
        }
        bom[idx2] += (h - A * (cum[idx2] - cum[idx1 - 1]) + A - 1) / A;
        cum[idx2] += (h - A * (cum[idx2] - cum[idx1 - 1]) + A - 1) / A;
    }
    cout << cum[j-1] << endl;

    return 0;
};


Compiler output:
a.cc: In function 'int main()':
a.cc:132:18: error: base operand of '->' has non-pointer type '__gnu_cxx::__alloc_traits<std::allocator<std::pair<long long int, long long int> >, std::pair<long long int, long long int> >::value_type' {aka 'std::pair<long long int, long long int>'}
  132 |     ll x = fox[0]->first;
      |                  ^~
a.cc:139:22: error: base operand of '->' has non-pointer type '__gnu_cxx::__alloc_traits<std::allocator<std::pair<long long int, long long int> >, std::pair<long long int, long long int> >::value_type' {aka 'std::pair<long long int, long long int>'}
  139 |         ll x = fox[i]->first;
      |                      ^~
a.cc:141:27: error: no matching function for call to 'distance(std::vector<std::pair<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> > >&)'
  141 |         int idx = distance(interval.begin(), itr);
      |                   ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/14/bits/stl_algobase.h:66,
                 from /usr/include/c++/14/bits/specfun.h:43,
                 from /usr/include/c++/14/cmath:3906,
                 from a.cc:10:
/usr/include/c++/14/bits/stl_iterator_base_funcs.h:148:5: note: candidate: 'template<class _InputIterator> constexpr typename std::iterator_traits< <template-parameter-1-1> >::difference_type std::distance(_InputIterator, _InputIterator)'
  148 |     distance(_InputIterator __first, _InputIterator __last)
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator_base_funcs.h:148:5: note:   template argument deduction/substitution failed:
a.cc:141:27: note:   deduced conflicting types for parameter '_InputIterator' ('__gnu_cxx::__normal_iterator<std::pair<int, int>*, std::vector<std::pair<int, int> > >' and '__gnu_cxx::__normal_iterator<std::pair<long long int, long long int>*, std::vector<std::pair<long long int, long long int> > >')
  141 |         int idx = distance(interval.begin(), itr);
      |                   ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
a.cc:142:28: error: base operand of '->' has non-pointer type '__gnu_cxx::__alloc_traits<std::allocator<std::pair<int, int> >, std::pair<int, int> >::value_type' {aka 'std::pair<int, int>'}
  142 |         if (interval[j - 1]->second < idx){
      |                            ^~
a.cc:151:22: error: base operand of '->' has non-pointer type '__gnu_cxx::__alloc_traits<std::allocator<std::pair<long long int, long long int> >, std::pair<long long int, long long int> >::value_type' {aka 'std::pair<long long int, long long int>'}
  151 |         ll h = fox[h]->second;
      |                      ^~
In file included from /usr/include/c++/14/bits/stl_algobase.h:71:
/usr/include/c++/14/bits/predefined_ops.h: In instantiation of 'bool __gnu_cxx::__ops::_Iter_less_val::operator()(_Iterator, _Value&) const [with _Iterator = __gnu_cxx::__normal_iterator<std::pair<int, int>*, std::vector<std::pair<int, int> > >; _Value = const std::pair<long long int, long long int>]':
/usr/include/c++/14/bits/stl_algobase.h:1504:14:   required from '_ForwardIterator std::__lower_bound(_ForwardIterator, _ForwardIterator, const _Tp&, _Compare) [with _ForwardIterator = __gnu_cxx::__normal_iterator<pair<int, int>*, vector<pair<int, int> > >; _Tp = pair<long long int, long long int>; _Compare = __gnu_cxx::__ops::_Iter_less_val]'
 1504 |           if (__comp(__middle, __val))
      |               ~~~~~~^~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algobase.h:1539:32:   required from '_ForwardIterator std::lower_bound(_ForwardIterator, _ForwardIterator, const _Tp&) [with _ForwardIterator = __gnu_cxx::__normal_iterator<pair<int, int>*, vector<pair<int, int> > >; _Tp = pair<long long int, long long int>]'
 1539 |       return std::__lower_bound(__first, __last, __val,
      |              ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
 1540 |                                 __gnu_cxx::__ops::__iter_less_val());
      |                                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
a.cc:152:32:   required from here
  152 |         auto itr1 = lower_bound(ALL(interval), make_pair(-INF, i));
      |                     ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/predefined_ops.h:69:22: error: no match for 'operator<' (operand types are 'std::pair<int, int>' and 'const std::pair<long long int, long long int>')
   69 |       { return *__it < __val; }
      |                ~~~~~~^~~~~~~
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:69:22: note:   'std::pair<int, int>' is not derived from 'const __gnu_cxx::__normal_iterator<_IteratorL, _Container>'
   69 |       { return *__it < __val; }
      |                ~~~~~~^~~~~~~
/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:69:22: note:   'std::pair<int, int>' is not derived from 'const __gnu_cxx::__normal_iterator<_Iterator, _Container>'
   69 |       { return *__it < __val; }
      |                ~~~~~~^~~~~~~
In file included from /usr/include/c++/14/regex:68,
                 from a.cc:76:
/usr/include/c++/14/bits/regex.h:1143:5: note: candidate: 'template<class _BiIter> bool std::__cxx11::operator<(const sub_match<_BiIter>&, const sub_match<_BiIter>&)'
 1143 |     operator<(const sub_match<_BiIter>& __lhs, const sub_match<_BiIter>& __rhs)
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1143:5: note:   template argument deduction/substitution failed:
/usr/include/c++/14/bits/predefined_ops.h:69:22: note:   'std::pair<int, int>' is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   69 |       { return *__it < __val; }
      |                ~~~~~~^~~~~~~
/usr/include/c++/14/bits/regex.h:1224:5: note: candidate: 'template<class _Bi_iter, class _Ch_traits, class _Ch_alloc> bool std::__cxx11::operator<(__sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>&, const sub_match<_BiIter>&)'
 1224 |     operator<(const __sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1224:5: note:   template argument deduction/substitution failed:
/usr/include/c++/14/bits/predefined_ops.h:69:22: note:   'std::pair<int, int>' is not derived from 'std::__cxx11::__sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>'
   69 |       { return *__it < __val; }
      |                ~~~~~~^~~~~~~
/usr/include/c++/14/bits/regex.h:1317:5: note: candidate: 'template<class _Bi_iter, class _Ch_traits, class _Ch_alloc> bool std::__cxx11::operator<(const sub_match<_BiIter>&, __sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>&)'
 1317 |     operator<(const sub_match<_Bi_iter>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1317:5: note:   template argument deduction/substitution failed:
/usr/include/c++/14/bits/predefined_ops.h:69:22: note:   'std::pair<int, int>' is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   69 |       { return *__it < __val; }
      |                ~~~~~~^~~~~~~
/usr/include/c++/14/bits/regex.h:1391:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator<(const typename std::iterator_traits<_Iter>::value_type*, const sub_match<_BiIter>&)'
 1391 |     operator<(typename iterator_traits<_Bi_iter>::value_type const* __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1391:5: note:   template argument deduction/substitution failed:
/usr/include/c++/14/bits/predefined_ops.h:69:22: note:   'const std::pair<long long int, long long int>' is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   69 |       { return *__it < __val; }
      |                ~~~~~~^~~~~~~
/usr/include/c++/14/bits/regex.h:1485:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator<(const sub_match<_BiIter>&, const typename std::iterator_traits<_Iter>::value_type*)'
 1485 |     operator<(const sub_match<_Bi_iter>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1485:5: note:   template argument deduction/substitution failed:
/usr/include/c++/14/bits/predefined_ops.h:69:22: note:   'std::pair<int, int>' is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   69 |       { return *__it < __val; }
      |                ~~~~~~^~~~~~~
/usr/include/c++/14/bits/regex.h:1560:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator<(const typename std::iterator_traits<_Iter>::value_type&, const sub_match<_BiIter>&)'
 1560 |     operator<(typename iterator_traits<_Bi_iter>::value_type const& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1560:5: note:   template argument deduction/substitution failed:
/usr/include/c++/14/bits/predefined_ops.h:69:22: note:   'const std::pair<long long int, long long int>' is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   69 |       { return *__it < __val; }
      |                ~~~~~~^~~~~~~
/usr/include/c++/14/bits/regex.h:1660:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator<(const sub_match<_BiIter>&, const typename std::iterator_traits<_Iter>::value_type&)'
 1660 |     operator<(const sub_match<_Bi_iter>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1660:5: note:   template argument deduction/substitution failed:
/usr/include/c++/14/bits/predefined_ops.h:69:22: note:   'std::pai