Language: C++

#include<bits/stdc++.h>
using namespace std;
int main(){string S;cin>>S;int b=S.size();int x=0;
           for(int i=0;i<b-3;i++){string p=S.substr(i,b-i);int q=atoi(p);while(q<2019){if(q%2019==0)x++;p/10;}}
           cout<<x<<endl;}


Compiler output:
a.cc: In function 'int main()':
a.cc:4:71: error: cannot convert 'std::string' {aka 'std::__cxx11::basic_string<char>'} to 'const char*'
    4 |            for(int i=0;i<b-3;i++){string p=S.substr(i,b-i);int q=atoi(p);while(q<2019){if(q%2019==0)x++;p/10;}}
      |                                                                       ^
      |                                                                       |
      |                                                                       std::string {aka std::__cxx11::basic_string<char>}
In file included from /usr/include/c++/14/cstdlib:79,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:42,
                 from a.cc:1:
/usr/include/stdlib.h:105:30: note:   initializing argument 1 of 'int atoi(const char*)'
  105 | extern int atoi (const char *__nptr)
      |                  ~~~~~~~~~~~~^~~~~~
a.cc:4:106: error: no match for 'operator/' (operand types are 'std::string' {aka 'std::__cxx11::basic_string<char>'} and 'int')
    4 |            for(int i=0;i<b-3;i++){string p=S.substr(i,b-i);int q=atoi(p);while(q<2019){if(q%2019==0)x++;p/10;}}
      |                                                                                                         ~^~~
      |                                                                                                         | |
      |                                                                                                         | int
      |                                                                                                         std::string {aka std::__cxx11::basic_string<char>}
In file included from /usr/include/c++/14/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:127:
/usr/include/c++/14/complex:430:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::operator/(const complex<_Tp>&, const complex<_Tp>&)'
  430 |     operator/(const complex<_Tp>& __x, const complex<_Tp>& __y)
      |     ^~~~~~~~
/usr/include/c++/14/complex:430:5: note:   template argument deduction/substitution failed:
a.cc:4:107: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::complex<_Tp>'
    4 |            for(int i=0;i<b-3;i++){string p=S.substr(i,b-i);int q=atoi(p);while(q<2019){if(q%2019==0)x++;p/10;}}
      |                                                                                                           ^~
/usr/include/c++/14/complex:439:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::operator/(const complex<_Tp>&, const _Tp&)'
  439 |     operator/(const complex<_Tp>& __x, const _Tp& __y)
      |     ^~~~~~~~
/usr/include/c++/14/complex:439:5: note:   template argument deduction/substitution failed:
a.cc:4:107: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::complex<_Tp>'
    4 |            for(int i=0;i<b-3;i++){string p=S.substr(i,b-i);int q=atoi(p);while(q<2019){if(q%2019==0)x++;p/10;}}
      |                                                                                                           ^~
/usr/include/c++/14/complex:448:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::operator/(const _Tp&, const complex<_Tp>&)'
  448 |     operator/(const _Tp& __x, const complex<_Tp>& __y)
      |     ^~~~~~~~
/usr/include/c++/14/complex:448:5: note:   template argument deduction/substitution failed:
a.cc:4:107: note:   mismatched types 'const std::complex<_Tp>' and 'int'
    4 |            for(int i=0;i<b-3;i++){string p=S.substr(i,b-i);int q=atoi(p);while(q<2019){if(q%2019==0)x++;p/10;}}
      |                                                                                                           ^~
In file included from /usr/include/c++/14/valarray:605,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:166:
/usr/include/c++/14/bits/valarray_after.h:408:5: note: candidate: 'template<class _Dom1, class _Dom2> std::_Expr<std::__detail::_BinClos<std::__divides, std::_Expr, std::_Expr, _Dom1, _Dom2>, typename std::__fun<std::__divides, typename _Dom1::value_type>::result_type> std::operator/(const _Expr<_Dom1, typename _Dom1::value_type>&, const _Expr<_Dom2, typename _Dom2::value_type>&)'
  408 |     _DEFINE_EXPR_BINARY_OPERATOR(/, struct std::__divides)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:408:5: note:   template argument deduction/substitution failed:
a.cc:4:107: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
    4 |            for(int i=0;i<b-3;i++){string p=S.substr(i,b-i);int q=atoi(p);while(q<2019){if(q%2019==0)x++;p/10;}}
      |                                                                                                           ^~
/usr/include/c++/14/bits/valarray_after.h:408:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__divides, std::_Expr, std::_Constant, _Dom, typename _Dom::value_type>, typename std::__fun<std::__divides, typename _Dom1::value_type>::result_type> std::operator/(const _Expr<_Dom1, typename _Dom1::value_type>&, const typename _Dom::value_type&)'
  408 |     _DEFINE_EXPR_BINARY_OPERATOR(/, struct std::__divides)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:408:5: note:   template argument deduction/substitution failed:
a.cc:4:107: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
    4 |            for(int i=0;i<b-3;i++){string p=S.substr(i,b-i);int q=atoi(p);while(q<2019){if(q%2019==0)x++;p/10;}}
      |                                                                                                           ^~
/usr/include/c++/14/bits/valarray_after.h:408:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__divides, std::_Constant, std::_Expr, typename _Dom::value_type, _Dom>, typename std::__fun<std::__divides, typename _Dom1::value_type>::result_type> std::operator/(const typename _Dom::value_type&, const _Expr<_Dom1, typename _Dom1::value_type>&)'
  408 |     _DEFINE_EXPR_BINARY_OPERATOR(/, struct std::__divides)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:408:5: note:   template argument deduction/substitution failed:
a.cc:4:107: note:   mismatched types 'const std::_Expr<_Dom1, typename _Dom1::value_type>' and 'int'
    4 |            for(int i=0;i<b-3;i++){string p=S.substr(i,b-i);int q=atoi(p);while(q<2019){if(q%2019==0)x++;p/10;}}
      |                                                                                                           ^~
/usr/include/c++/14/bits/valarray_after.h:408:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__divides, std::_Expr, std::_ValArray, _Dom, typename _Dom::value_type>, typename std::__fun<std::__divides, typename _Dom1::value_type>::result_type> std::operator/(const _Expr<_Dom1, typename _Dom1::value_type>&, const valarray<typename _Dom::value_type>&)'
  408 |     _DEFINE_EXPR_BINARY_OPERATOR(/, struct std::__divides)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:408:5: note:   template argument deduction/substitution failed:
a.cc:4:107: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
    4 |            for(int i=0;i<b-3;i++){string p=S.substr(i,b-i);int q=atoi(p);while(q<2019){if(q%2019==0)x++;p/10;}}
      |                                                                                                           ^~
/usr/include/c++/14/bits/valarray_after.h:408:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__divides, std::_ValArray, std::_Expr, typename _Dom::value_type, _Dom>, typename std::__fun<std::__divides, typename _Dom1::value_type>::result_type> std::operator/(const valarray<typename _Dom::value_type>&, const _Expr<_Dom1, typename _Dom1::value_type>&)'
  408 |     _DEFINE_EXPR_BINARY_OPERATOR(/, struct std::__divides)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:408:5: note:   template argument deduction/substitution failed:
a.cc:4:107: note:   mismatched types 'const std::_Expr<_Dom1, typename _Dom1::value_type>' and 'int'
    4 |            for(int i=0;i<b-3;i++){string p=S.substr(i,b-i);int q=atoi(p);while(q<2019){if(q%2019==0)x++;p/10;}}
      |                                                                                                           ^~
/usr/include/c++/14/valarray:1199:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__divides, std::_ValArray, std::_ValArray, _Tp, _Tp>, typename std::__fun<std::__divides, _Tp>::result_type> std::operator/(const valarray<_Tp>&, const valarray<_Tp>&)'
 1199 | _DEFINE_BINARY_OPERATOR(/, __divides)
      | ^~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/valarray:1199:1: note:   template argument deduction/substitution failed:
a.cc:4:107: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::valarray<_Tp>'
    4 |            for(int i=0;i<b-3;i++){string p=S.substr(i,b-i);int q=atoi(p);while(q<2019){if(q%2019==0)x++;p/10;}}
      |                                                                                                           ^~
/usr/include/c++/14/valarray:1199:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__divides, std::_ValArray, std::_Constant, _Tp, _Tp>, typename std::__fun<std::__divides, _Tp>::result_type> std::operator/(const valarray<_Tp>&, const typename valarray<_Tp>::value_type&)'
 1199 | _DEFINE_BINARY_OPERATOR(/, __divides)
      | ^~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/valarray:1199:1: note:   template argument deduction/substitution failed:
a.cc:4:107: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::valarray<_Tp>'
    4 |            for(int i=0;i<b-3;i++){string p=S.substr(i,b-i);int q=atoi(p);while(q<2019){if(q%