Language: C++

#include<bits/stdc++.h>
using namespace std;

int main(){
  int W,H;
  cin >> H >> W;
  vector<vector<string>> Board(H,vector<string>(W));
  for(int i = 0; i < H; ++i){
    for(int j = 0; j < W; ++j){
      cin >> Board.at(i).at(j);
    }
  }
  bool flag;
  for(int i = 0; i < H; ++i){
    flag = true;
    for(int j = 0; j < W; ++j){
      flag *= (Board.at(i).at(j)==".");
    }
    if(flag){
      for(int j = 0; j < W; ++j){
        Board.at(i).at(j) = "e";
      }
    }
  }
  for(int i = 0; i < W; ++i){
    flag = true;
    for(int j = 0; j < H; ++j){
      flag *= ((Board.at(j).at(i)==".") || (Board.at(j).at(i) = "e"));
    }
    if(flag){
      for(int j = 0; j < H; ++j){
        Board.at(i).at(j) = "e";
      }
    }
  }
  for(int i = 0; i < H; ++i){
    for(int j = 0; j < W; ++j){
      if(Board.at(i).at(j) != "e"){
        cout << Board.at(i).at(j) ;
      }
    }
    cout << endl;
  }
}

Compiler output:
a.cc: In function 'int main()':
a.cc:28:41: error: no match for 'operator||' (operand types are 'bool' and 'std::__cxx11::basic_string<char>')
   28 |       flag *= ((Board.at(j).at(i)==".") || (Board.at(j).at(i) = "e"));
      |                ~~~~~~~~~~~~~~~~~~~~~~~~ ^~ ~~~~~~~~~~~~~~~~~~~~~~~~~
      |                                  |                            |
      |                                  bool                         std::__cxx11::basic_string<char>
a.cc:28:41: note: candidate: 'operator||(bool, bool)' (built-in)
   28 |       flag *= ((Board.at(j).at(i)==".") || (Board.at(j).at(i) = "e"));
      |                ~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
a.cc:28:41: note:   no known conversion for argument 2 from 'std::__cxx11::basic_string<char>' to 'bool'
In file included from /usr/include/c++/14/valarray:605,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:166,
                 from a.cc:1:
/usr/include/c++/14/bits/valarray_after.h:416:5: note: candidate: 'template<class _Dom1, class _Dom2> std::_Expr<std::__detail::_BinClos<std::__logical_or, std::_Expr, std::_Expr, _Dom1, _Dom2>, typename std::__fun<std::__logical_or, typename _Dom1::value_type>::result_type> std::operator||(const _Expr<_Dom1, typename _Dom1::value_type>&, const _Expr<_Dom2, typename _Dom2::value_type>&)'
  416 |     _DEFINE_EXPR_BINARY_OPERATOR(||, struct std::__logical_or)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:416:5: note:   template argument deduction/substitution failed:
a.cc:28:68: note:   mismatched types 'const std::_Expr<_Dom1, typename _Dom1::value_type>' and 'bool'
   28 |       flag *= ((Board.at(j).at(i)==".") || (Board.at(j).at(i) = "e"));
      |                                                                    ^
/usr/include/c++/14/bits/valarray_after.h:416:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__logical_or, std::_Expr, std::_Constant, _Dom, typename _Dom::value_type>, typename std::__fun<std::__logical_or, typename _Dom1::value_type>::result_type> std::operator||(const _Expr<_Dom1, typename _Dom1::value_type>&, const typename _Dom::value_type&)'
  416 |     _DEFINE_EXPR_BINARY_OPERATOR(||, struct std::__logical_or)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:416:5: note:   template argument deduction/substitution failed:
a.cc:28:68: note:   mismatched types 'const std::_Expr<_Dom1, typename _Dom1::value_type>' and 'bool'
   28 |       flag *= ((Board.at(j).at(i)==".") || (Board.at(j).at(i) = "e"));
      |                                                                    ^
/usr/include/c++/14/bits/valarray_after.h:416:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__logical_or, std::_Constant, std::_Expr, typename _Dom::value_type, _Dom>, typename std::__fun<std::__logical_or, typename _Dom1::value_type>::result_type> std::operator||(const typename _Dom::value_type&, const _Expr<_Dom1, typename _Dom1::value_type>&)'
  416 |     _DEFINE_EXPR_BINARY_OPERATOR(||, struct std::__logical_or)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:416:5: note:   template argument deduction/substitution failed:
a.cc:28:68: note:   'std::__cxx11::basic_string<char>' is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
   28 |       flag *= ((Board.at(j).at(i)==".") || (Board.at(j).at(i) = "e"));
      |                                                                    ^
/usr/include/c++/14/bits/valarray_after.h:416:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__logical_or, std::_Expr, std::_ValArray, _Dom, typename _Dom::value_type>, typename std::__fun<std::__logical_or, typename _Dom1::value_type>::result_type> std::operator||(const _Expr<_Dom1, typename _Dom1::value_type>&, const valarray<typename _Dom::value_type>&)'
  416 |     _DEFINE_EXPR_BINARY_OPERATOR(||, struct std::__logical_or)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:416:5: note:   template argument deduction/substitution failed:
a.cc:28:68: note:   mismatched types 'const std::_Expr<_Dom1, typename _Dom1::value_type>' and 'bool'
   28 |       flag *= ((Board.at(j).at(i)==".") || (Board.at(j).at(i) = "e"));
      |                                                                    ^
/usr/include/c++/14/bits/valarray_after.h:416:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__logical_or, std::_ValArray, std::_Expr, typename _Dom::value_type, _Dom>, typename std::__fun<std::__logical_or, typename _Dom1::value_type>::result_type> std::operator||(const valarray<typename _Dom::value_type>&, const _Expr<_Dom1, typename _Dom1::value_type>&)'
  416 |     _DEFINE_EXPR_BINARY_OPERATOR(||, struct std::__logical_or)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:416:5: note:   template argument deduction/substitution failed:
a.cc:28:68: note:   'std::__cxx11::basic_string<char>' is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
   28 |       flag *= ((Board.at(j).at(i)==".") || (Board.at(j).at(i) = "e"));
      |                                                                    ^
/usr/include/c++/14/valarray:1207:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__logical_or, std::_ValArray, std::_ValArray, _Tp, _Tp>, typename std::__fun<std::__logical_or, _Tp>::result_type> std::operator||(const valarray<_Tp>&, const valarray<_Tp>&)'
 1207 | _DEFINE_BINARY_OPERATOR(||, __logical_or)
      | ^~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/valarray:1207:1: note:   template argument deduction/substitution failed:
a.cc:28:68: note:   mismatched types 'const std::valarray<_Tp>' and 'bool'
   28 |       flag *= ((Board.at(j).at(i)==".") || (Board.at(j).at(i) = "e"));
      |                                                                    ^
/usr/include/c++/14/valarray:1207:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__logical_or, std::_ValArray, std::_Constant, _Tp, _Tp>, typename std::__fun<std::__logical_or, _Tp>::result_type> std::operator||(const valarray<_Tp>&, const typename valarray<_Tp>::value_type&)'
 1207 | _DEFINE_BINARY_OPERATOR(||, __logical_or)
      | ^~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/valarray:1207:1: note:   template argument deduction/substitution failed:
a.cc:28:68: note:   mismatched types 'const std::valarray<_Tp>' and 'bool'
   28 |       flag *= ((Board.at(j).at(i)==".") || (Board.at(j).at(i) = "e"));
      |                                                                    ^
/usr/include/c++/14/valarray:1207:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__logical_or, std::_Constant, std::_ValArray, _Tp, _Tp>, typename std::__fun<std::__logical_or, _Tp>::result_type> std::operator||(const typename valarray<_Tp>::value_type&, const valarray<_Tp>&)'
 1207 | _DEFINE_BINARY_OPERATOR(||, __logical_or)
      | ^~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/valarray:1207:1: note:   template argument deduction/substitution failed:
a.cc:28:68: note:   'std::__cxx11::basic_string<char>' is not derived from 'const std::valarray<_Tp>'
   28 |       flag *= ((Board.at(j).at(i)==".") || (Board.at(j).at(i) = "e"));
      |                                                                    ^