Language: C++

#include<bits/stdc++.h>

#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define int long long

using namespace std;

//v.push_back(123);
//sort(v.begin(), v.end(),greater<int>());
//for(int x : v) {cout << x << endl;}

//for(int x: v) cout << x << endl;
//vector<vector<char>> v(H, vector<char>(W));
//vector<int> v(1000);

int aiueo[100010];

void calculation(long long num){
  if(num==1) return 2;
  if(aiueo[num]!=-1) return aiueo[num];
  return 3*aiueo[num-1]%1000000007;
} 

long long calcuation(long long num){

  long long res=1;
  int aiueo = pow(3, 20) % 1000000007;
  res *= ((num / 20) * aiueo) % 1000000007;
  res *= 2*
  return res;
}

signed main(){
  string L;
  cin>>L;

  rep(i, 100010) aiueo[i]=-1;
  calculation(100009);
  vector<int> v;

  int count = 0;
  int MOD = 1000000007;
  int result=0;
  rep(i, L.length){
     if(S[L.length-i-1]==1){
       result = (result + (pow(2,count)%MOD)*aiueo[L.length-i-1])%MOD;
       count++;
     }

  }

  cout << res << endl;
  
  return 0;
}


Compiler output:
a.cc: In function 'void calculation(long long int)':
a.cc:19:21: error: return-statement with a value, in function returning 'void' [-fpermissive]
   19 |   if(num==1) return 2;
      |                     ^
a.cc:20:38: error: return-statement with a value, in function returning 'void' [-fpermissive]
   20 |   if(aiueo[num]!=-1) return aiueo[num];
      |                             ~~~~~~~~~^
a.cc:21:24: error: return-statement with a value, in function returning 'void' [-fpermissive]
   21 |   return 3*aiueo[num-1]%1000000007;
      |          ~~~~~~~~~~~~~~^~~~~~~~~~~
a.cc: In function 'long long int calcuation(long long int)':
a.cc:27:26: error: invalid operands of types '__gnu_cxx::__promote<double>::__type' {aka 'double'} and 'int' to binary 'operator%'
   27 |   int aiueo = pow(3, 20) % 1000000007;
      |               ~~~~~~~~~~ ^ ~~~~~~~~~~
      |                  |         |
      |                  |         int
      |                  __gnu_cxx::__promote<double>::__type {aka double}
a.cc:30:3: error: expected primary-expression before 'return'
   30 |   return res;
      |   ^~~~~~
a.cc:31:1: warning: no return statement in function returning non-void [-Wreturn-type]
   31 | }
      | ^
a.cc: In function 'int main()':
a.cc:44:12: error: invalid use of member function 'std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::size_type std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::length() const [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>; size_type = long unsigned int]' (did you forget the '()' ?)
   44 |   rep(i, L.length){
      |            ^
a.cc:3:38: note: in definition of macro 'rep'
    3 | #define rep(i,n) for(int i=0;i<(int)(n);i++)
      |                                      ^
a.cc:45:9: error: 'S' was not declared in this scope
   45 |      if(S[L.length-i-1]==1){
      |         ^
a.cc:45:13: error: invalid use of member function 'std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::size_type std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::length() const [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>; size_type = long unsigned int]' (did you forget the '()' ?)
   45 |      if(S[L.length-i-1]==1){
      |           ~~^~~~~~
      |                   ()
a.cc:46:40: error: invalid operands of types '__gnu_cxx::__promote<double>::__type' {aka 'double'} and 'long long int' to binary 'operator%'
   46 |        result = (result + (pow(2,count)%MOD)*aiueo[L.length-i-1])%MOD;
      |                            ~~~~~~~~~~~~^~~~
      |                               |         |
      |                               |         long long int
      |                               __gnu_cxx::__promote<double>::__type {aka double}
a.cc:46:54: error: invalid use of member function 'std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::size_type std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::length() const [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>; size_type = long unsigned int]' (did you forget the '()' ?)
   46 |        result = (result + (pow(2,count)%MOD)*aiueo[L.length-i-1])%MOD;
      |                                                    ~~^~~~~~
      |                                                            ()
a.cc:52:11: error: 'res' was not declared in this scope; did you mean 'rep'?
   52 |   cout << res << endl;
      |           ^~~
      |           rep