Language: C++

#include<iostream>
#include<string>
using namespace std;
 
int main(){
  string s;
  if(s.at(0) == "R" && s.at(1) == "R" && s.at(2) == "R"){
    cout << "3";
  }
  else if(s.at(0) == "R" && s.at(1) == "R" && s.at(2) == "S" || s.at(0) == "S" && s.at(1) == "R" && s.at(2) == "R"){
    cout << "2";
  }
  else if(s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "R"||s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "S"||s.at(0) == "S" && s.at(1) == "R" && s.at(2) == "S"||s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "R"||s.at(0) == "S" && s.at(1) == "S" && s.at(2) == "R"){
    cout << "1";
  }
  else{
    cout << "0";
  }
}

Compiler output:
a.cc: In function 'int main()':
a.cc:7:14: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
    7 |   if(s.at(0) == "R" && s.at(1) == "R" && s.at(2) == "R"){
      |      ~~~~~~~~^~~~~~
a.cc:7:32: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
    7 |   if(s.at(0) == "R" && s.at(1) == "R" && s.at(2) == "R"){
      |                        ~~~~~~~~^~~~~~
a.cc:7:50: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
    7 |   if(s.at(0) == "R" && s.at(1) == "R" && s.at(2) == "R"){
      |                                          ~~~~~~~~^~~~~~
a.cc:10:19: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   10 |   else if(s.at(0) == "R" && s.at(1) == "R" && s.at(2) == "S" || s.at(0) == "S" && s.at(1) == "R" && s.at(2) == "R"){
      |           ~~~~~~~~^~~~~~
a.cc:10:37: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   10 |   else if(s.at(0) == "R" && s.at(1) == "R" && s.at(2) == "S" || s.at(0) == "S" && s.at(1) == "R" && s.at(2) == "R"){
      |                             ~~~~~~~~^~~~~~
a.cc:10:55: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   10 |   else if(s.at(0) == "R" && s.at(1) == "R" && s.at(2) == "S" || s.at(0) == "S" && s.at(1) == "R" && s.at(2) == "R"){
      |                                               ~~~~~~~~^~~~~~
a.cc:10:73: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   10 |   else if(s.at(0) == "R" && s.at(1) == "R" && s.at(2) == "S" || s.at(0) == "S" && s.at(1) == "R" && s.at(2) == "R"){
      |                                                                 ~~~~~~~~^~~~~~
a.cc:10:91: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   10 |   else if(s.at(0) == "R" && s.at(1) == "R" && s.at(2) == "S" || s.at(0) == "S" && s.at(1) == "R" && s.at(2) == "R"){
      |                                                                                   ~~~~~~~~^~~~~~
a.cc:10:109: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   10 |   else if(s.at(0) == "R" && s.at(1) == "R" && s.at(2) == "S" || s.at(0) == "S" && s.at(1) == "R" && s.at(2) == "R"){
      |                                                                                                     ~~~~~~~~^~~~~~
a.cc:13:19: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   13 |   else if(s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "R"||s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "S"||s.at(0) == "S" && s.at(1) == "R" && s.at(2) == "S"||s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "R"||s.at(0) == "S" && s.at(1) == "S" && s.at(2) == "R"){
      |           ~~~~~~~~^~~~~~
a.cc:13:37: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   13 |   else if(s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "R"||s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "S"||s.at(0) == "S" && s.at(1) == "R" && s.at(2) == "S"||s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "R"||s.at(0) == "S" && s.at(1) == "S" && s.at(2) == "R"){
      |                             ~~~~~~~~^~~~~~
a.cc:13:55: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   13 |   else if(s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "R"||s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "S"||s.at(0) == "S" && s.at(1) == "R" && s.at(2) == "S"||s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "R"||s.at(0) == "S" && s.at(1) == "S" && s.at(2) == "R"){
      |                                               ~~~~~~~~^~~~~~
a.cc:13:71: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   13 |   else if(s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "R"||s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "S"||s.at(0) == "S" && s.at(1) == "R" && s.at(2) == "S"||s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "R"||s.at(0) == "S" && s.at(1) == "S" && s.at(2) == "R"){
      |                                                               ~~~~~~~~^~~~~~
a.cc:13:89: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   13 |   else if(s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "R"||s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "S"||s.at(0) == "S" && s.at(1) == "R" && s.at(2) == "S"||s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "R"||s.at(0) == "S" && s.at(1) == "S" && s.at(2) == "R"){
      |                                                                                 ~~~~~~~~^~~~~~
a.cc:13:107: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   13 |   else if(s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "R"||s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "S"||s.at(0) == "S" && s.at(1) == "R" && s.at(2) == "S"||s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "R"||s.at(0) == "S" && s.at(1) == "S" && s.at(2) == "R"){
      |                                                                                                   ~~~~~~~~^~~~~~
a.cc:13:123: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   13 |   else if(s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "R"||s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "S"||s.at(0) == "S" && s.at(1) == "R" && s.at(2) == "S"||s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "R"||s.at(0) == "S" && s.at(1) == "S" && s.at(2) == "R"){
      |                                                                                                                   ~~~~~~~~^~~~~~
a.cc:13:141: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   13 |   else if(s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "R"||s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "S"||s.at(0) == "S" && s.at(1) == "R" && s.at(2) == "S"||s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "R"||s.at(0) == "S" && s.at(1) == "S" && s.at(2) == "R"){
      |                                                                                                                                     ~~~~~~~~^~~~~~
a.cc:13:159: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   13 |   else if(s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "R"||s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "S"||s.at(0) == "S" && s.at(1) == "R" && s.at(2) == "S"||s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "R"||s.at(0) == "S" && s.at(1) == "S" && s.at(2) == "R"){
      |                                                                                                                                                       ~~~~~~~~^~~~~~
a.cc:13:175: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   13 |   else if(s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "R"||s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "S"||s.at(0) == "S" && s.at(1) == "R" && s.at(2) == "S"||s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "R"||s.at(0) == "S" && s.at(1) == "S" && s.at(2) == "R"){
      |                                                                                                                                                                       ~~~~~~~~^~~~~~
a.cc:13:193: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   13 |   else if(s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "R"||s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "S"||s.at(0) == "S" && s.at(1) == "R" && s.at(2) == "S"||s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "R"||s.at(0) == "S" && s.at(1) == "S" && s.at(2) == "R"){
      |                                                                                                                                                                                         ~~~~~~~~^~~~~~
a.cc:13:211: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   13 |   else if(s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "R"||s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "S"||s.at(0) == "S" && s.at(1) == "R" && s.at(2) == "S"||s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "R"||s.at(0) == "S" && s.at(1) == "S" && s.at(2) == "R"){
      |                                                                                                                                                                                                           ~~~~~~~~^~~~~~
a.cc:13:227: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   13 |   else if(s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "R"||s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "S"||s.at(0) == "S" && s.at(1) == "R" && s.at(2) == "S"||s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "R"||s.at(0) == "S" && s.at(1) == "S" && s.at(2) == "R"){
      |                                                                                                                                                                                                                           ~~~~~~~~^~~~~~
a.cc:13:245: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   13 |   else if(s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "R"||s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "S"||s.at(0) == "S" && s.at(1) == "R" && s.at(2) == "S"||s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "R"||s.at(0) == "S" && s.at(1) == "S" && s.at(2) == "R"){
      |                                                                                                                                                                                                                                             ~~~~~~~~^~~~~~
a.cc:13:263: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   13 |   else if(s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "R"||s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "S"||s.at(0) == "S" && s.at(1) == "R" && s.at(2) == "S"||s.at(0) == "R" && s.at(1) == "S" && s.at(2) == "R"||s.at(0) == "S" && s.at(1) == "S" && s.at(2) == "R"){
      |                                                                                                                                                                                                                                                               ~~~~~~~~^~~~~~