Language: C++

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

int main(){
   int A,B,K;
   cin>>A>>B>>K;
   vector<int> a (B-A+1);
   for(int i=0;i<=B-A;i++){
       a.at(i)=i+A;
   }
   if(2*K<=B-A+1){
   vector<> b (2*K);
   for(int i=0;i<K;i++){
        b.at(i)=a.at(i);
   }
   reverse (a.begin(),a.end());
   for(int i=0;i<K;i++){
       b.at(K+i)=a.at(i);
   }
   sort (b.begin(),b.end());
   
   
   
  for(int i=0;i<2*K;i++){
       if(i<2*K-1){
         if(b.at(i)==b.at(i+1)){
           continue;
         }
       }
       cout<<b.at(i)<<endl;
   }
   }
   else{
       for(int i=0;i<B-A+1;i++){
        cout<<a.at(i)<<endl;
       }
   }

   }
       
   


Compiler output:
a.cc:2:18: error: declaration does not declare anything [-fpermissive]
    2 | #define int long long;
      |                  ^~~~
a.cc:5:1: note: in expansion of macro 'int'
    5 | int main(){
      | ^~~
a.cc:5:5: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
    5 | int main(){
      |     ^~~~
a.cc: In function 'int main()':
a.cc:2:18: error: declaration does not declare anything [-fpermissive]
    2 | #define int long long;
      |                  ^~~~
a.cc:6:4: note: in expansion of macro 'int'
    6 |    int A,B,K;
      |    ^~~
a.cc:6:8: error: 'A' was not declared in this scope
    6 |    int A,B,K;
      |        ^
a.cc:6:10: error: 'B' was not declared in this scope
    6 |    int A,B,K;
      |          ^
a.cc:6:12: error: 'K' was not declared in this scope
    6 |    int A,B,K;
      |            ^
a.cc:2:18: error: template argument 1 is invalid
    2 | #define int long long;
      |                  ^~~~
a.cc:8:11: note: in expansion of macro 'int'
    8 |    vector<int> a (B-A+1);
      |           ^~~
a.cc:2:18: error: template argument 2 is invalid
    2 | #define int long long;
      |                  ^~~~
a.cc:8:11: note: in expansion of macro 'int'
    8 |    vector<int> a (B-A+1);
      |           ^~~
a.cc:8:14: error: expected primary-expression before '>' token
    8 |    vector<int> a (B-A+1);
      |              ^
a.cc:8:16: error: 'a' was not declared in this scope
    8 |    vector<int> a (B-A+1);
      |                ^
a.cc:2:18: error: declaration does not declare anything [-fpermissive]
    2 | #define int long long;
      |                  ^~~~
a.cc:9:8: note: in expansion of macro 'int'
    9 |    for(int i=0;i<=B-A;i++){
      |        ^~~
a.cc:9:12: error: 'i' was not declared in this scope
    9 |    for(int i=0;i<=B-A;i++){
      |            ^
a.cc:9:22: error: expected ')' before ';' token
    9 |    for(int i=0;i<=B-A;i++){
      |       ~              ^
      |                      )
a.cc:9:23: error: 'i' was not declared in this scope
    9 |    for(int i=0;i<=B-A;i++){
      |                       ^
a.cc:13:11: error: wrong number of template arguments (0, should be at least 1)
   13 |    vector<> b (2*K);
      |           ^
In file included from /usr/include/c++/14/vector:66,
                 from /usr/include/c++/14/functional:64,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:53,
                 from a.cc:1:
/usr/include/c++/14/bits/stl_vector.h:428:11: note: provided for 'template<class _Tp, class _Alloc> class std::vector'
  428 |     class vector : protected _Vector_base<_Tp, _Alloc>
      |           ^~~~~~
a.cc:2:18: error: declaration does not declare anything [-fpermissive]
    2 | #define int long long;
      |                  ^~~~
a.cc:14:8: note: in expansion of macro 'int'
   14 |    for(int i=0;i<K;i++){
      |        ^~~
a.cc:14:19: error: expected ')' before ';' token
   14 |    for(int i=0;i<K;i++){
      |       ~           ^
      |                   )
a.cc:2:18: error: declaration does not declare anything [-fpermissive]
    2 | #define int long long;
      |                  ^~~~
a.cc:18:8: note: in expansion of macro 'int'
   18 |    for(int i=0;i<K;i++){
      |        ^~~
a.cc:18:19: error: expected ')' before ';' token
   18 |    for(int i=0;i<K;i++){
      |       ~           ^
      |                   )
a.cc:21:12: error: request for member 'begin' in 'b', which is of non-class type 'int'
   21 |    sort (b.begin(),b.end());
      |            ^~~~~
a.cc:21:22: error: request for member 'end' in 'b', which is of non-class type 'int'
   21 |    sort (b.begin(),b.end());
      |                      ^~~
a.cc:2:18: error: declaration does not declare anything [-fpermissive]
    2 | #define int long long;
      |                  ^~~~
a.cc:25:7: note: in expansion of macro 'int'
   25 |   for(int i=0;i<2*K;i++){
      |       ^~~
a.cc:25:20: error: expected ')' before ';' token
   25 |   for(int i=0;i<2*K;i++){
      |      ~             ^
      |                    )
a.cc:2:18: error: declaration does not declare anything [-fpermissive]
    2 | #define int long long;
      |                  ^~~~
a.cc:35:12: note: in expansion of macro 'int'
   35 |        for(int i=0;i<B-A+1;i++){
      |            ^~~
a.cc:35:27: error: expected ')' before ';' token
   35 |        for(int i=0;i<B-A+1;i++){
      |           ~               ^
      |                           )