Language: C++

#include<iostream>
#include<string>
using namespace std;
int main(){
  string s;cin>>s;
  if(s='abc'||s='acb'||s='bac'||s='bca'||s='cab'||s='cba')cout<<"Yes";
  else cout<<"No";
}

Compiler output:
a.cc:6:8: warning: multi-character character constant [-Wmultichar]
    6 |   if(s='abc'||s='acb'||s='bac'||s='bca'||s='cab'||s='cba')cout<<"Yes";
      |        ^~~~~
a.cc:6:17: warning: multi-character character constant [-Wmultichar]
    6 |   if(s='abc'||s='acb'||s='bac'||s='bca'||s='cab'||s='cba')cout<<"Yes";
      |                 ^~~~~
a.cc:6:26: warning: multi-character character constant [-Wmultichar]
    6 |   if(s='abc'||s='acb'||s='bac'||s='bca'||s='cab'||s='cba')cout<<"Yes";
      |                          ^~~~~
a.cc:6:35: warning: multi-character character constant [-Wmultichar]
    6 |   if(s='abc'||s='acb'||s='bac'||s='bca'||s='cab'||s='cba')cout<<"Yes";
      |                                   ^~~~~
a.cc:6:44: warning: multi-character character constant [-Wmultichar]
    6 |   if(s='abc'||s='acb'||s='bac'||s='bca'||s='cab'||s='cba')cout<<"Yes";
      |                                            ^~~~~
a.cc:6:53: warning: multi-character character constant [-Wmultichar]
    6 |   if(s='abc'||s='acb'||s='bac'||s='bca'||s='cab'||s='cba')cout<<"Yes";
      |                                                     ^~~~~
a.cc: In function 'int main()':
a.cc:6:13: error: no match for 'operator||' (operand types are 'int' and 'std::string' {aka 'std::__cxx11::basic_string<char>'})
    6 |   if(s='abc'||s='acb'||s='bac'||s='bca'||s='cab'||s='cba')cout<<"Yes";
      |        ~~~~~^~~
      |        |      |
      |        int    std::string {aka std::__cxx11::basic_string<char>}
a.cc:6:13: note: candidate: 'operator||(bool, bool)' (built-in)
    6 |   if(s='abc'||s='acb'||s='bac'||s='bca'||s='cab'||s='cba')cout<<"Yes";
      |        ~~~~~^~~
a.cc:6:13: note:   no known conversion for argument 2 from 'std::string' {aka 'std::__cxx11::basic_string<char>'} to 'bool'
a.cc:6:22: error: no match for 'operator||' (operand types are 'int' and 'std::string' {aka 'std::__cxx11::basic_string<char>'})
    6 |   if(s='abc'||s='acb'||s='bac'||s='bca'||s='cab'||s='cba')cout<<"Yes";
      |                 ~~~~~^~~
      |                 |      |
      |                 int    std::string {aka std::__cxx11::basic_string<char>}
a.cc:6:22: note: candidate: 'operator||(bool, bool)' (built-in)
    6 |   if(s='abc'||s='acb'||s='bac'||s='bca'||s='cab'||s='cba')cout<<"Yes";
      |                 ~~~~~^~~
a.cc:6:22: note:   no known conversion for argument 2 from 'std::string' {aka 'std::__cxx11::basic_string<char>'} to 'bool'
a.cc:6:31: error: no match for 'operator||' (operand types are 'int' and 'std::string' {aka 'std::__cxx11::basic_string<char>'})
    6 |   if(s='abc'||s='acb'||s='bac'||s='bca'||s='cab'||s='cba')cout<<"Yes";
      |                          ~~~~~^~~
      |                          |      |
      |                          int    std::string {aka std::__cxx11::basic_string<char>}
a.cc:6:31: note: candidate: 'operator||(bool, bool)' (built-in)
    6 |   if(s='abc'||s='acb'||s='bac'||s='bca'||s='cab'||s='cba')cout<<"Yes";
      |                          ~~~~~^~~
a.cc:6:31: note:   no known conversion for argument 2 from 'std::string' {aka 'std::__cxx11::basic_string<char>'} to 'bool'
a.cc:6:40: error: no match for 'operator||' (operand types are 'int' and 'std::string' {aka 'std::__cxx11::basic_string<char>'})
    6 |   if(s='abc'||s='acb'||s='bac'||s='bca'||s='cab'||s='cba')cout<<"Yes";
      |                                   ~~~~~^~~
      |                                   |      |
      |                                   int    std::string {aka std::__cxx11::basic_string<char>}
a.cc:6:40: note: candidate: 'operator||(bool, bool)' (built-in)
    6 |   if(s='abc'||s='acb'||s='bac'||s='bca'||s='cab'||s='cba')cout<<"Yes";
      |                                   ~~~~~^~~
a.cc:6:40: note:   no known conversion for argument 2 from 'std::string' {aka 'std::__cxx11::basic_string<char>'} to 'bool'
a.cc:6:49: error: no match for 'operator||' (operand types are 'int' and 'std::string' {aka 'std::__cxx11::basic_string<char>'})
    6 |   if(s='abc'||s='acb'||s='bac'||s='bca'||s='cab'||s='cba')cout<<"Yes";
      |                                            ~~~~~^~~
      |                                            |      |
      |                                            int    std::string {aka std::__cxx11::basic_string<char>}
a.cc:6:49: note: candidate: 'operator||(bool, bool)' (built-in)
    6 |   if(s='abc'||s='acb'||s='bac'||s='bca'||s='cab'||s='cba')cout<<"Yes";
      |                                            ~~~~~^~~
a.cc:6:49: note:   no known conversion for argument 2 from 'std::string' {aka 'std::__cxx11::basic_string<char>'} to 'bool'