Language: C++

#include <iostream>
#include <algorithm>
#include <stack>
using namespace std;
int main(){
    string a;
    stack<string>s;
	cin>>a;
	for(int i=0;i<a.size();i++){
	    if(a[i]=='0'){s.push('0');}
	    else if(a[i]=='1'){s.push('1');}
	    else{s.pop();}
	}
	cout<<s<<endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:10:33: error: no matching function for call to 'std::stack<std::__cxx11::basic_string<char> >::push(char)'
   10 |             if(a[i]=='0'){s.push('0');}
      |                           ~~~~~~^~~~~
In file included from /usr/include/c++/14/stack:63,
                 from a.cc:3:
/usr/include/c++/14/bits/stl_stack.h:258:7: note: candidate: 'void std::stack<_Tp, _Sequence>::push(const value_type&) [with _Tp = std::__cxx11::basic_string<char>; _Sequence = std::deque<std::__cxx11::basic_string<char>, std::allocator<std::__cxx11::basic_string<char> > >; value_type = std::__cxx11::basic_string<char>]'
  258 |       push(const value_type& __x)
      |       ^~~~
/usr/include/c++/14/bits/stl_stack.h:258:30: note:   no known conversion for argument 1 from 'char' to 'const std::stack<std::__cxx11::basic_string<char> >::value_type&' {aka 'const std::__cxx11::basic_string<char>&'}
  258 |       push(const value_type& __x)
      |            ~~~~~~~~~~~~~~~~~~^~~
/usr/include/c++/14/bits/stl_stack.h:263:7: note: candidate: 'void std::stack<_Tp, _Sequence>::push(value_type&&) [with _Tp = std::__cxx11::basic_string<char>; _Sequence = std::deque<std::__cxx11::basic_string<char>, std::allocator<std::__cxx11::basic_string<char> > >; value_type = std::__cxx11::basic_string<char>]'
  263 |       push(value_type&& __x)
      |       ^~~~
/usr/include/c++/14/bits/stl_stack.h:263:25: note:   no known conversion for argument 1 from 'char' to 'std::stack<std::__cxx11::basic_string<char> >::value_type&&' {aka 'std::__cxx11::basic_string<char>&&'}
  263 |       push(value_type&& __x)
      |            ~~~~~~~~~~~~~^~~
a.cc:11:38: error: no matching function for call to 'std::stack<std::__cxx11::basic_string<char> >::push(char)'
   11 |             else if(a[i]=='1'){s.push('1');}
      |                                ~~~~~~^~~~~
/usr/include/c++/14/bits/stl_stack.h:258:7: note: candidate: 'void std::stack<_Tp, _Sequence>::push(const value_type&) [with _Tp = std::__cxx11::basic_string<char>; _Sequence = std::deque<std::__cxx11::basic_string<char>, std::allocator<std::__cxx11::basic_string<char> > >; value_type = std::__cxx11::basic_string<char>]'
  258 |       push(const value_type& __x)
      |       ^~~~
/usr/include/c++/14/bits/stl_stack.h:258:30: note:   no known conversion for argument 1 from 'char' to 'const std::stack<std::__cxx11::basic_string<char> >::value_type&' {aka 'const std::__cxx11::basic_string<char>&'}
  258 |       push(const value_type& __x)
      |            ~~~~~~~~~~~~~~~~~~^~~
/usr/include/c++/14/bits/stl_stack.h:263:7: note: candidate: 'void std::stack<_Tp, _Sequence>::push(value_type&&) [with _Tp = std::__cxx11::basic_string<char>; _Sequence = std::deque<std::__cxx11::basic_string<char>, std::allocator<std::__cxx11::basic_string<char> > >; value_type = std::__cxx11::basic_string<char>]'
  263 |       push(value_type&& __x)
      |       ^~~~
/usr/include/c++/14/bits/stl_stack.h:263:25: note:   no known conversion for argument 1 from 'char' to 'std::stack<std::__cxx11::basic_string<char> >::value_type&&' {aka 'std::__cxx11::basic_string<char>&&'}
  263 |       push(value_type&& __x)
      |            ~~~~~~~~~~~~~^~~
a.cc:14:13: error: no match for 'operator<<' (operand types are 'std::ostream' {aka 'std::basic_ostream<char>'} and 'std::stack<std::__cxx11::basic_string<char> >')
   14 |         cout<<s<<endl;
      |         ~~~~^~~
      |         |     |
      |         |     std::stack<std::__cxx11::basic_string<char> >
      |         std::ostream {aka std::basic_ostream<char>}
In file included from /usr/include/c++/14/iostream:41,
                 from a.cc:1:
/usr/include/c++/14/ostream:116:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(__ostream_type& (*)(__ostream_type&)) [with _CharT = char; _Traits = std::char_traits<char>; __ostream_type = std::basic_ostream<char>]'
  116 |       operator<<(__ostream_type& (*__pf)(__ostream_type&))
      |       ^~~~~~~~
/usr/include/c++/14/ostream:116:36: note:   no known conversion for argument 1 from 'std::stack<std::__cxx11::basic_string<char> >' to 'std::basic_ostream<char>::__ostream_type& (*)(std::basic_ostream<char>::__ostream_type&)' {aka 'std::basic_ostream<char>& (*)(std::basic_ostream<char>&)'}
  116 |       operator<<(__ostream_type& (*__pf)(__ostream_type&))
      |                  ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/ostream:125:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(__ios_type& (*)(__ios_type&)) [with _CharT = char; _Traits = std::char_traits<char>; __ostream_type = std::basic_ostream<char>; __ios_type = std::basic_ios<char>]'
  125 |       operator<<(__ios_type& (*__pf)(__ios_type&))
      |       ^~~~~~~~
/usr/include/c++/14/ostream:125:32: note:   no known conversion for argument 1 from 'std::stack<std::__cxx11::basic_string<char> >' to 'std::basic_ostream<char>::__ios_type& (*)(std::basic_ostream<char>::__ios_type&)' {aka 'std::basic_ios<char>& (*)(std::basic_ios<char>&)'}
  125 |       operator<<(__ios_type& (*__pf)(__ios_type&))
      |                  ~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~
/usr/include/c++/14/ostream:135:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(std::ios_base& (*)(std::ios_base&)) [with _CharT = char; _Traits = std::char_traits<char>; __ostream_type = std::basic_ostream<char>]'
  135 |       operator<<(ios_base& (*__pf) (ios_base&))
      |       ^~~~~~~~
/usr/include/c++/14/ostream:135:30: note:   no known conversion for argument 1 from 'std::stack<std::__cxx11::basic_string<char> >' to 'std::ios_base& (*)(std::ios_base&)'
  135 |       operator<<(ios_base& (*__pf) (ios_base&))
      |                  ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~
/usr/include/c++/14/ostream:174:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(long int) [with _CharT = char; _Traits = std::char_traits<char>; __ostream_type = std::basic_ostream<char>]'
  174 |       operator<<(long __n)
      |       ^~~~~~~~
/usr/include/c++/14/ostream:174:23: note:   no known conversion for argument 1 from 'std::stack<std::__cxx11::basic_string<char> >' to 'long int'
  174 |       operator<<(long __n)
      |                  ~~~~~^~~
/usr/include/c++/14/ostream:178:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(long unsigned int) [with _CharT = char; _Traits = std::char_traits<char>; __ostream_type = std::basic_ostream<char>]'
  178 |       operator<<(unsigned long __n)
      |       ^~~~~~~~
/usr/include/c++/14/ostream:178:32: note:   no known conversion for argument 1 from 'std::stack<std::__cxx11::basic_string<char> >' to 'long unsigned int'
  178 |       operator<<(unsigned long __n)
      |                  ~~~~~~~~~~~~~~^~~
/usr/include/c++/14/ostream:182:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(bool) [with _CharT = char; _Traits = std::char_traits<char>; __ostream_type = std::basic_ostream<char>]'
  182 |       operator<<(bool __n)
      |       ^~~~~~~~
/usr/include/c++/14/ostream:182:23: note:   no known conversion for argument 1 from 'std::stack<std::__cxx11::basic_string<char> >' to 'bool'
  182 |       operator<<(bool __n)
      |                  ~~~~~^~~
In file included from /usr/include/c++/14/ostream:1022:
/usr/include/c++/14/bits/ostream.tcc:96:5: note: candidate: 'std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(short int) [with _CharT = char; _Traits = std::char_traits<char>]'
   96 |     basic_ostream<_CharT, _Traits>::
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/ostream.tcc:97:22: note:   no known conversion for argument 1 from 'std::stack<std::__cxx11::basic_string<char> >' to 'short int'
   97 |     operator<<(short __n)
      |                ~~~~~~^~~
/usr/include/c++/14/ostream:189:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(short unsigned int) [with _CharT = char; _Traits = std::char_traits<char>; __ostream_type = std::basic_ostream<char>]'
  189 |       operator<<(unsigned short __n)
      |       ^~~~~~~~
/usr/include/c++/14/ostream:189:33: note:   no known conversion for argument 1 from 'std::stack<std::__cxx11::basic_string<char> >' to 'short unsigned int'
  189 |       operator<<(unsigned short __n)
      |                  ~~~~~~~~~~~~~~~^~~
/usr/include/c++/14/bits/ostream.tcc:110:5: note: candidate: 'std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(int) [with _CharT = char; _Traits = std::char_traits<char>]'
  110 |     basic_ostream<_CharT, _Traits>::
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/ostream.tcc:111:20: note:   no known conversion for argument 1 from 'std::stack<std::__cxx11::basic_string<char> >' to 'int'
  111 |     operator<<(int __n)
      |                ~~~~^~~
/usr/include/c++/14/ostream:200:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(unsigned int) [with _CharT = char; _Traits = std::char_traits<char>; __ostream_type = std::basic_ostream<char>]'
  200 |       operator<<(unsigned int __n)
      |       ^~~~~~~~
/usr/include/c++/14/ostream:200:31: note:   no known conversion for argument 1 from 'std::stack<std::__cxx11::basic_string<char> >' to 'unsigned int'
  200 |       operator<<(unsigned int __n)
      |                  ~~~~~~~~~~~~~^~~
/usr/include/c++/14/ostream:211:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(long long int) [with _CharT = char; _Traits = std::char_traits<char>; __ostream_type = std::basic_ostream<char>]'
  211 |       operator<<(long long __n)
      |       ^~~~~~~~
/usr/include/c++/14/ostream:211:28: note:   no known conversion for argument 1 from 'std::stack<std::_