criyle/codenet-compile-errors huggingface dataset:
Language: C++

#define _USE_MATH_DEFINES
#include <bits/stdc++.h>

using namespace std;

int main()
{
    string str, cmd, p;
    int q, a, b, i;

    cin >> str >> q;

    for (i = 0; i < q; i++)
    {
        cin >> cmd;
        if (cmd == "print")
        {
            cin >> a >> b;
            cout << str.substr(a, b - a + 1) << endl;
        }
        else if (cmd == "reverse")
        {
            cin >> a >> b;
            reverse(a, b);
        }
        else
        {
            cin >> a >> b >> p;
            str.replace(a, b - a + 1, p);
        }
    }
}


Compiler output:
In file included from /usr/include/c++/14/algorithm:61,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:51,
                 from a.cc:2:
/usr/include/c++/14/bits/stl_algo.h: In instantiation of 'void std::reverse(_BIter, _BIter) [with _BIter = int]':
a.cc:24:20:   required from here
   24 |             reverse(a, b);
      |             ~~~~~~~^~~~~~
/usr/include/c++/14/bits/stl_algo.h:1089:63: error: no matching function for call to '__iterator_category(int&)'
 1089 |       std::__reverse(__first, __last, std::__iterator_category(__first));
      |                                       ~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~
In file included from /usr/include/c++/14/bits/stl_algobase.h:65,
                 from /usr/include/c++/14/algorithm:60:
/usr/include/c++/14/bits/stl_iterator_base_types.h:239:5: note: candidate: 'template<class _Iter> constexpr typename std::iterator_traits< <template-parameter-1-1> >::iterator_category std::__iterator_category(const _Iter&)'
  239 |     __iterator_category(const _Iter&)
      |     ^~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_iterator_base_types.h:239:5: note:   template argument deduction/substitution failed:
/usr/include/c++/14/bits/stl_iterator_base_types.h: In substitution of 'template<class _Iter> constexpr typename std::iterator_traits< <template-parameter-1-1> >::iterator_category std::__iterator_category(const _Iter&) [with _Iter = int]':
/usr/include/c++/14/bits/stl_algo.h:1089:63:   required from 'void std::reverse(_BIter, _BIter) [with _BIter = int]'
 1089 |       std::__reverse(__first, __last, std::__iterator_category(__first));
      |                                       ~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~
a.cc:24:20:   required from here
   24 |             reverse(a, b);
      |             ~~~~~~~^~~~~~
/usr/include/c++/14/bits/stl_iterator_base_types.h:239:5: error: no type named 'iterator_category' in 'struct std::iterator_traits<int>'
  239 |     __iterator_category(const _Iter&)
      |     ^~~~~~~~~~~~~~~~~~~
Language: C++

#include<iostream>
#include<string>
using namespace std;
int main(){
    string s,c,x;
    int y,a,b;
    cin >> s >> y;
    for(int t=0;t < y;t++){
        cin >> c >> a >> b;
        if(c = "print"){
            
        }
    }
}


Compiler output:
a.cc: In function 'int main()':
a.cc:10:14: error: could not convert 'c.std::__cxx11::basic_string<char>::operator=(((const char*)"print"))' from 'std::__cxx11::basic_string<char>' to 'bool'
   10 |         if(c = "print"){
      |            ~~^~~~~~~~~
      |              |
      |              std::__cxx11::basic_string<char>
Language: C++

#include<iostream>
#include<string>
using namespace std;
int main(){
    string s,c,x;
    int y,a,b;
    cin >> s >> y;
    for(int t=0;t < y;t++){
        cin >> c >> a >> b;
        if(c = "print"){
            cout << s.substr(a,b-a+1) << endl;
        }
    }
}


Compiler output:
a.cc: In function 'int main()':
a.cc:10:14: error: could not convert 'c.std::__cxx11::basic_string<char>::operator=(((const char*)"print"))' from 'std::__cxx11::basic_string<char>' to 'bool'
   10 |         if(c = "print"){
      |            ~~^~~~~~~~~
      |              |
      |              std::__cxx11::basic_string<char>
Language: C++

#include<iostream>
#include<string>
using namespace std;
int main(){
    string s,c,x;
    int y,a,b;
    cin >> s >> y;
    for(int t=0;t < y;t++){
        cin >> c >> a >> b;
        if(c == "print"){
            cout << s.substr(a,b-a+1) << endl;
        }else if(c =="reverse"){
            string
        }
        
    }
}


Compiler output:
a.cc: In function 'int main()':
a.cc:14:9: error: expected unqualified-id before '}' token
   14 |         }
      |         ^
Language: C++

#include<iostream>
#include<string>
using namespace std;
int main(){
    string s,c,x;
    int y,a,b;
    cin >> s >> y;
    for(int t=0;t < y;t++){
        cin >> c >> a >> b;
        if(c == "print"){
            cout << s.substr(a,b-a+1) << endl;
        }else if(c =="reverse"){
            string k =s.substr(a,b-a+1);
            int n = k.size();
            for(int i =0;i<n;i++)
            
        }
        
    }
}


Compiler output:
a.cc: In function 'int main()':
a.cc:17:9: error: expected primary-expression before '}' token
   17 |         }
      |         ^
Language: C++

#include<iostream>
#include<string>
using namespace std;
int main(){
    string s,c,x;
    int y,a,b;
    cin >> s >> y;
    for(int t=0;t < y;t++){
        cin >> c >> a >> b;
        if(c == "print"){
            cout << s.substr(a,b-a+1) << endl;
        }else if(c =="reverse"){
            string k =s.substr(a,b-a+1);
            int n = k.size();
            for(int i =0;i<n;i++) s[i+a]=k[n-i-1];
        }else if (c == "replace"){
            cin >> x;
            s = s.replace(a,b-a+1,x)
        }
        
    }
}


Compiler output:
a.cc: In function 'int main()':
a.cc:18:37: error: expected ';' before '}' token
   18 |             s = s.replace(a,b-a+1,x)
      |                                     ^
      |                                     ;
   19 |         }
      |         ~
Language: C++

#include<iostream>
#include<string>
using namespace std;
int main(){
    string str,order,rev;
    int q,a,b;
    cin >> str >> q;
    for(int i = 1; i <= 3; i++){
        cin >> order;
        if(order == "print"){
            cin >> a >> b;
            for (int j = a; a <= b; j++){
                cout << str[j]
            }
            cout << endl;
        }
        else if(order == "reverse"){
            cin >> a>> b;
            for (int j = b; b >= a; j--){
                rev += str[j];
            }
            str = str.replace(a,b-a+1,rev)
        }
        if(order == "replace"){
            cin >> a >> b >> rev;
            str = str.replace(a,b-a+1,rev)
        }
    }
    return 0;
    
}


Compiler output:
a.cc: In function 'int main()':
a.cc:13:31: error: expected ';' before '}' token
   13 |                 cout << str[j]
      |                               ^
      |                               ;
   14 |             }
      |             ~                  
a.cc:22:43: error: expected ';' before '}' token
   22 |             str = str.replace(a,b-a+1,rev)
      |                                           ^
      |                                           ;
   23 |         }
      |         ~                                  
a.cc:26:43: error: expected ';' before '}' token
   26 |             str = str.replace(a,b-a+1,rev)
      |                                           ^
      |                                           ;
   27 |         }
      |         ~
Language: C++

#include<iostream>
#include<string>
using namespace std;
int main(){
    string str,order,rev;
    int q,a,b;
    cin >> str >> q;
    for(int i = 1; i <= 3; i++){
        cin >> order;
        if(order == "print"){
            cin >> a >> b;
            for (int j = a; a <= b; j++){
                cout << str[j];
            }
            cout << endl;
        }
        else if(order == "reverse"){
            cin >> a>> b;
            for (int j = b; b >= a; j--){
                rev += str[j];
            }
            str = str.replace(a,b-a+1,rev)
        }
        if(order == "replace"){
            cin >> a >> b >> rev;
            str = str.replace(a,b-a+1,rev)
        }
    }
    return 0;
    
}


Compiler output:
a.cc: In function 'int main()':
a.cc:22:43: error: expected ';' before '}' token
   22 |             str = str.replace(a,b-a+1,rev)
      |                                           ^
      |                                           ;
   23 |         }
      |         ~                                  
a.cc:26:43: error: expected ';' before '}' token
   26 |             str = str.replace(a,b-a+1,rev)
      |                                           ^
      |                                           ;
   27 |         }
      |         ~
Language: C++

#include<iostream>
#include<string>
using namespace std;

int main(){
    string target;
    int num;
    cin >> target;
    cin >> num;
    
    string com;
    for(int i =0; i<num; i++){
        cin >> com;
        if(com=="print"){
            int st,en;
            cin >> st >> en ;
            cout << target.substr(st,en+st-1) << endl;
        }
        else if (com=="replace"){
            int st,en;
            string str;
            cin >> st >> en >> str;
            target=target.replace(st,en-st+1,str)
        }else{
            int st,en;
            cin >> st >> en;
            string tmp =target.substr(st,st+en-1);
            int n =tmp.size();
            for (int i =0;i<n;i++) str[i+a]=tmp[n-i-1];
        }
    }
    return 0;
    
}


Compiler output:
a.cc: In function 'int main()':
a.cc:23:50: error: expected ';' before '}' token
   23 |             target=target.replace(st,en-st+1,str)
      |                                                  ^
      |                                                  ;
   24 |         }else{
      |         ~                                         
a.cc:29:36: error: 'str' was not declared in this scope; did you mean 'st'?
   29 |             for (int i =0;i<n;i++) str[i+a]=tmp[n-i-1];
      |                                    ^~~
      |                                    st
a.cc:29:42: error: 'a' was not declared in this scope
   29 |             for (int i =0;i<n;i++) str[i+a]=tmp[n-i-1];
      |                                          ^
Language: C++

#include<iostream>
#include<string>
using namespace std;
int main(){
    string str1;
    cin >>str1;
    int q,a,b;
    string str2, str3;
    
    for(int i=0; i<q; i++){
        cin >>str2 >>a >>b;
        if(str2 == "print"){
            cout <<str1.substr(a, b-a+1) <<endl;
        }else if(str2 == "reverse"){
            string str4 = substr(a,b-a+1);
            reverse(str4.begin(), str3.end());
            str1 = str1.substr(0,a) + str4 + str.substr(b+1, str1.size()-a-1); 
        }else{
            cin >>str3;
            str1 = str1.replace(a,b-a+1,str3);
        }
    }return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:15:27: error: 'substr' was not declared in this scope
   15 |             string str4 = substr(a,b-a+1);
      |                           ^~~~~~
a.cc:16:13: error: 'reverse' was not declared in this scope
   16 |             reverse(str4.begin(), str3.end());
      |             ^~~~~~~
a.cc:17:46: error: 'str' was not declared in this scope; did you mean 'str4'?
   17 |             str1 = str1.substr(0,a) + str4 + str.substr(b+1, str1.size()-a-1);
      |                                              ^~~
      |                                              str4
Language: C++

#include<iostream>
#include<string>
using namespace std;
int main(){
    string str1;
    cin >>str1;
    int q,a,b;
    string str2, str3;
    
    for(int i=0; i<q; i++){
        cin >>str2 >>a >>b;
        if(str2 == "print"){
            cout <<str1.substr(a, b-a+1) <<endl;
        }else if(str2 == "reverse"){
            string str4 = str1.substr(a,b-a+1);
            reverse(str4.begin(), str4.end());
            str1 = str1.substr(0,a) + str4 + str1.substr(b+1, str1.size()-a-1); 
        }else{
            cin >>str3;
            str1 = str1.replace(a,b-a+1,str3);
        }
    }return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:16:13: error: 'reverse' was not declared in this scope
   16 |             reverse(str4.begin(), str4.end());
      |             ^~~~~~~
Language: C++

#include<iostream>
#include<string>

int main(){
    stirng str,cmd,p;
    int n,a,b;
    cin >> str;
    cin >> n;
    for(int i = 1;i <= n;i++){
        cin >> cmd >> a >> b ;
        if(cmd == "print"){
           cout << str.substr(a-1,b - a + 1);
        } else if(cmd == "reverse"){
            str.reverse(a-1,b-1);
        } else if(cmd == "replace"){
            cin >> p;
            str.replace(a-1,b - a + 1,p);
        }
    }
    
    return 0;    
}



Compiler output:
a.cc: In function 'int main()':
a.cc:5:5: error: 'stirng' was not declared in this scope
    5 |     stirng str,cmd,p;
      |     ^~~~~~
a.cc:7:5: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    7 |     cin >> str;
      |     ^~~
      |     std::cin
In file included from a.cc:1:
/usr/include/c++/14/iostream:62:18: note: 'std::cin' declared here
   62 |   extern istream cin;           ///< Linked to standard input
      |                  ^~~
a.cc:7:12: error: 'str' was not declared in this scope; did you mean 'std'?
    7 |     cin >> str;
      |            ^~~
      |            std
a.cc:10:16: error: 'cmd' was not declared in this scope
   10 |         cin >> cmd >> a >> b ;
      |                ^~~
a.cc:12:12: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   12 |            cout << str.substr(a-1,b - a + 1);
      |            ^~~~
      |            std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
a.cc:16:20: error: 'p' was not declared in this scope
   16 |             cin >> p;
      |                    ^
Language: C++

#include<iostream>
using namespace std;

int main{
    string s;
    cin >> s;
    string n;
    cin >> n;
    while(n--){
         string t,r;
         cin >> t;
         if (t[2]=p){
            int a,b;
            cin >> a >> b >> r;
            for(i=a;i<=b;++i){
               int c = 0;
               t[i] = r[++c];
            }
         }
        else if(t[2]=v){
             int a,b;
             cin >> a >> b;
             for(i=a;i<=b;++i){
                t[i]=t[b-a-i];
             }
             }
        else {
             int a,b;
             cin >>a >>b;
             for(i=a;i<=b;++i){
                cout << t[i];
             }
             cout << endl;
             }
       }
return 0;
}

            
            


Compiler output:
a.cc:4:5: error: cannot declare '::main' to be a global variable
    4 | int main{
      |     ^~~~
a.cc:5:12: error: expected primary-expression before 's'
    5 |     string s;
      |            ^
a.cc:5:12: error: expected '}' before 's'
a.cc:4:9: note: to match this '{'
    4 | int main{
      |         ^
a.cc:6:5: error: 'cin' does not name a type
    6 |     cin >> s;
      |     ^~~
a.cc:8:5: error: 'cin' does not name a type
    8 |     cin >> n;
      |     ^~~
a.cc:9:5: error: expected unqualified-id before 'while'
    9 |     while(n--){
      |     ^~~~~
a.cc:36:1: error: expected unqualified-id before 'return'
   36 | return 0;
      | ^~~~~~
a.cc:37:1: error: expected declaration before '}' token
   37 | }
      | ^
Language: C++

#include<iostream>
using namespace std;

int main{
    string s;
    cin >> s;
    string n;
    cin >> n;
    while(n--){
         string t,r;
         cin >> t;
         if (t[2]='p'){
            int a,b;
            cin >> a >> b >> r;
            for(i=a;i<=b;++i){
               int c = 0;
               t[i] = r[++c];
            }
         }
        else if(t[2]='v'){
             int a,b;
             cin >> a >> b;
             for(i=a;i<=b;++i){
                t[i]=t[b-a-i];
             }
             }
        else {
             int a,b;
             cin >>a >>b;
             for(i=a;i<=b;++i){
                cout << t[i];
             }
             cout << endl;
             }
       }
return 0;
}

            
            


Compiler output:
a.cc:4:5: error: cannot declare '::main' to be a global variable
    4 | int main{
      |     ^~~~
a.cc:5:12: error: expected primary-expression before 's'
    5 |     string s;
      |            ^
a.cc:5:12: error: expected '}' before 's'
a.cc:4:9: note: to match this '{'
    4 | int main{
      |         ^
a.cc:6:5: error: 'cin' does not name a type
    6 |     cin >> s;
      |     ^~~
a.cc:8:5: error: 'cin' does not name a type
    8 |     cin >> n;
      |     ^~~
a.cc:9:5: error: expected unqualified-id before 'while'
    9 |     while(n--){
      |     ^~~~~
a.cc:36:1: error: expected unqualified-id before 'return'
   36 | return 0;
      | ^~~~~~
a.cc:37:1: error: expected declaration before '}' token
   37 | }
      | ^
Language: C++

#include<iostream>
using namespace std;

int main{
    string s;
    cin >> s;
    int n;
    cin >> n;
    while(n--){
         string t,r;
         cin >> t;
         if (t[2]='p'){
            int a,b;
            cin >> a >> b >> r;
            for(i=a;i<=b;++i){
               int c = 0;
               t[i] = r[++c];
            }
         }
        else if(t[2]='v'){
             int a,b;
             cin >> a >> b;
             for(i=a;i<=b;++i){
                t[i]=t[b-a-i];
             }
             }
        else {
             int a,b;
             cin >>a >>b;
             for(i=a;i<=b;++i){
                cout << t[i];
             }
             cout << endl;
             }
       }
return 0;
}

            
            


Compiler output:
a.cc:4:5: error: cannot declare '::main' to be a global variable
    4 | int main{
      |     ^~~~
a.cc:5:12: error: expected primary-expression before 's'
    5 |     string s;
      |            ^
a.cc:5:12: error: expected '}' before 's'
a.cc:4:9: note: to match this '{'
    4 | int main{
      |         ^
a.cc:6:5: error: 'cin' does not name a type
    6 |     cin >> s;
      |     ^~~
a.cc:8:5: error: 'cin' does not name a type
    8 |     cin >> n;
      |     ^~~
a.cc:9:5: error: expected unqualified-id before 'while'
    9 |     while(n--){
      |     ^~~~~
a.cc:36:1: error: expected unqualified-id before 'return'
   36 | return 0;
      | ^~~~~~
a.cc:37:1: error: expected declaration before '}' token
   37 | }
      | ^
Language: C++

#include<iostream>
using namespace std;

int main{
    string soi;
    cin >> soi;
    int n;
    cin >> n;
    while(n--){
         string t,r;
         cin >> t;
         if (t[2]='p'){
            int a,b;
            cin >> a >> b >> r;
            for(i=a;i<=b;++i){
               int c = 0;
               soi[i] = r[++c];
            }
         }
        else if(t[2]='v'){
             int a,b;
             cin >> a >> b;
             for(i=a;i<=b;++i){
                soi[i]=soi[b-a-i];
             }
             }
        else {
             int a,b;
             cin >>a >>b;
             for(i=a;i<=b;++i){
                cout << soi[i];
             }
             cout << endl;
             }
       }
return 0;
}

            
            


Compiler output:
a.cc:4:5: error: cannot declare '::main' to be a global variable
    4 | int main{
      |     ^~~~
a.cc:5:12: error: expected primary-expression before 'soi'
    5 |     string soi;
      |            ^~~
a.cc:5:12: error: expected '}' before 'soi'
a.cc:4:9: note: to match this '{'
    4 | int main{
      |         ^
a.cc:6:5: error: 'cin' does not name a type
    6 |     cin >> soi;
      |     ^~~
a.cc:8:5: error: 'cin' does not name a type
    8 |     cin >> n;
      |     ^~~
a.cc:9:5: error: expected unqualified-id before 'while'
    9 |     while(n--){
      |     ^~~~~
a.cc:36:1: error: expected unqualified-id before 'return'
   36 | return 0;
      | ^~~~~~
a.cc:37:1: error: expected declaration before '}' token
   37 | }
      | ^
Language: C++

#include<iostream>
#include<string>
using namespace std;

int main(){
    
    string str,str1,str2;
    int q;
    int a, b;
    
    cin >> str;
    cin >> q;
    for ( int i = 0; i < q; q++ ){
        cin >> str1 >> a >> b;
        if ( str1 == "replace" ){
            cin >> str2;
            str.replace(a, b-a+1, str2);
        }
        if ( str1 == "reverse"){
            for ( int j = 0; j < (b-a+1); j++){
                if ( a+j == b-j) continue;
                str.replace(a+j,1,str(b-j));
            }
        }
        if ( str1 == "print") cout << str.substr(a, b-a) << endl;
    }
    return 0;
}



Compiler output:
a.cc: In function 'int main()':
a.cc:22:38: error: no match for call to '(std::string {aka std::__cxx11::basic_string<char>}) (int)'
   22 |                 str.replace(a+j,1,str(b-j));
      |                                   ~~~^~~~~
Language: C++

#include<iostream>
#include<string>
using namespace std;

int main(){
    
    string str,str1,str2;
    int q;
    int a, b;
    
    cin >> str;
    cin >> q;
    for ( int i = 0; i < q; q++ ){
        cin >> str1 >> a >> b;
        if ( str1 == "replace" ){
            cin >> str2;
            str.replace(a, b-a+1, str2);
        }
        if ( str1 == "reverse"){
            for ( int j = 0; j < (b-a); j++){
                strreplace(a+j,1,str[b-j]);
            }
        }
        if ( str1 == "print") cout << str.substr(a, b-a) << endl;
    }
    return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:21:17: error: 'strreplace' was not declared in this scope
   21 |                 strreplace(a+j,1,str[b-j]);
      |                 ^~~~~~~~~~
Language: C++

#include<iostream>
#include<string>
using namespace std;

int main(){
    
    string str,str1,str2;
    int q;
    int a, b;
    
    cin >> str;
    cin >> q;
    for ( int i = 0; i < q; q++ ){
        cin >> str1 >> a >> b;
        if ( str1 == "replace" ){
            cin >> str2;
            str.replace(a, b-a+1, str2);
        }
        if ( str1 == "reverse"){
            for ( int j = 0; j < (b-a); j++){
                strreplace(a+j,1,str[b-j]);
            }
        }
        if ( str1 == "print") cout << str.substr(a, b-a) << endl;
    }
    return 0;
}



Compiler output:
a.cc: In function 'int main()':
a.cc:21:17: error: 'strreplace' was not declared in this scope
   21 |                 strreplace(a+j,1,str[b-j]);
      |                 ^~~~~~~~~~
Language: C++

#include<iostream>
#include<string>
using namespace std;
int main(){
    string str;
    int q;
    
    string order, p;
    int a, b;
    
    string str2;
    
    for(int i = 0; i < q; i++){
        cin >> order >> a >> b >> p;
        
        if(order == "print"){
            for(int j = a; j <= b; j++){
                cout << string[j]; << " ";
            }
            cout << endl;
        }
        
        else if(order == "reverse"){
            for(int k = b; k >= a; k--){
                str2 = str2 + string[k];
            }
            
            str.replace(a, b, str2);
        }
        
        else if(order == "replace"){
            cout << str.replace(a, b, p) << endl;
        }
    }
}


Compiler output:
a.cc: In function 'int main()':
a.cc:18:31: error: expected primary-expression before '[' token
   18 |                 cout << string[j]; << " ";
      |                               ^
a.cc:18:36: error: expected primary-expression before '<<' token
   18 |                 cout << string[j]; << " ";
      |                                    ^~
a.cc:25:37: error: expected primary-expression before '[' token
   25 |                 str2 = str2 + string[k];
      |                                     ^
Language: C++

#include<iostream>
#include<string>
using namespace std;
int main(){
    string str;
    int q;
    
    string order, p;
    int a, b;
    
    string str2;
    
    for(int i = 0; i < q; i++){
        cin >> order >> a >> b >> p;
        
        if(order == "print"){
            for(int j = a; j <= b; j++){
                cout << string[j] << " ";
            }
            cout << endl;
        }
        
        else if(order == "reverse"){
            for(int k = b; k >= a; k--){
                str2 = str2 + string[k];
            }
            
            str.replace(a, b, str2);
        }
        
        else if(order == "replace"){
            cout << str.replace(a, b, p) << endl;
        }
    }
}


Compiler output:
a.cc: In function 'int main()':
a.cc:18:31: error: expected primary-expression before '[' token
   18 |                 cout << string[j] << " ";
      |                               ^
a.cc:25:37: error: expected primary-expression before '[' token
   25 |                 str2 = str2 + string[k];
      |                                     ^
Language: C++

#include<iostream>
#include<string>
using namespace std;
int main(){
    string str;
    int q;
    
    string order, p;
    int a, b;
    
    string str2;
    
    for(int i = 0; i < q; i++){
        cin >> order >> a >> b >> p;
        
        if(order == "print"){
            for(int j = a; j <= b; j++){
                cout << string[j] << " ";
            }
            cout << endl;
        }
        
        else if(order == "reverse"){
            for(int k = b; k >= a; k--){
                str2 = str2 + str[k];
            }
            
            str.replace(a, b, str2);
        }
        
        else if(order == "replace"){
            cout << str.replace(a, b, p) << endl;
        }
    }
}


Compiler output:
a.cc: In function 'int main()':
a.cc:18:31: error: expected primary-expression before '[' token
   18 |                 cout << string[j] << " ";
      |                               ^
Language: C++

#include<iostream>
#include<string>
using namespace std;

int main(){
    
    string str,str1,str2,str3;
    int q;
    int a, b;
    
    cin >> str;
    cin >> q;
    for ( int i = 0; i < q; q++ ){
        cin >> str1 >> a >> b;
        if ( str1 == "replace" ){
            cin >> str2;
            str.replace(a, b-a+1, str2);
        }
        if ( str1 == "reverse"){
            for ( int j = b; j >= a; j--){
                str3 += str[j]
            }
                str.replace(a,b-a+1,str3);
        }
        if ( str1 == "print") cout << str.substr(a, b-a) << endl;
    }
    return 0;
}



Compiler output:
a.cc: In function 'int main()':
a.cc:21:31: error: expected ';' before '}' token
   21 |                 str3 += str[j]
      |                               ^
      |                               ;
   22 |             }
      |             ~
Language: C++

#include<iostream>
#include<string>
using namespace std;
int main(){
    
    string str;
    int q;
    
    string order, p;
    int a, b;
    
    string str2;
    
    cin >> str >> q;
    
    for(int i = 1; i < q; i++){
        cin >> order >> a >> b >> p;
        
        if(order == "print"){
            cout << str.substr(a, b-a) << endl;
            }
            cout << endl;
        }
        
        else if(order == "reverse"){
            for(int k = b; k >= a; k--){
                str2 = str2 + str[k];
            }
            
            str.replace(a, b-a+1, str2);
        }
        
        else if(order == "replace"){
            str = str.replace(a, b-a+1, p);
        }
    }

    return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:25:9: error: 'else' without a previous 'if'
   25 |         else if(order == "reverse"){
      |         ^~~~
a.cc: At global scope:
a.cc:38:5: error: expected unqualified-id before 'return'
   38 |     return 0;
      |     ^~~~~~
a.cc:39:1: error: expected declaration before '}' token
   39 | }
      | ^
Language: C++

#include<iostream>
#include<string>
using namespace std;

string reverse(string s,int n,int m){
    string t =s.substr(n,m);
    string u;
    for (int i = 0; i < t.size-1; i++){
        u[i] = t[t.size-1-i];
    }
    return s.replace(n,m,u);
}


Compiler output:
a.cc: In function 'std::string reverse(std::string, int, int)':
a.cc:8:27: error: invalid use of member function 'std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::size_type std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::size() const [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>; size_type = long unsigned int]' (did you forget the '()' ?)
    8 |     for (int i = 0; i < t.size-1; i++){
      |                         ~~^~~~
      |                               ()
a.cc:9:20: error: invalid use of member function 'std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::size_type std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::size() const [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>; size_type = long unsigned int]' (did you forget the '()' ?)
    9 |         u[i] = t[t.size-1-i];
      |                  ~~^~~~
      |                        ()
Language: C++

#include<iostream>
#include<string>
using namespace std;

string reverse(string s,int n,int m){
    string t =s.substr(n,m);
    string u;
    for (int i = 0; i < (t.size-1); i++){
        u[i] = t[t.size-1-i];
    }
    return s.replace(n,m,u);
}


Compiler output:
a.cc: In function 'std::string reverse(std::string, int, int)':
a.cc:8:28: error: invalid use of member function 'std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::size_type std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::size() const [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>; size_type = long unsigned int]' (did you forget the '()' ?)
    8 |     for (int i = 0; i < (t.size-1); i++){
      |                          ~~^~~~
      |                                ()
a.cc:9:20: error: invalid use of member function 'std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::size_type std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::size() const [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>; size_type = long unsigned int]' (did you forget the '()' ?)
    9 |         u[i] = t[t.size-1-i];
      |                  ~~^~~~
      |                        ()
Language: C++

#include<iostream>
#include<string>
using namespace std;

string reverse(string s,int n,int m){
    string t =s.substr(n,m);
    string u;
    for (int i = 0; i < t.size()-1; i++){
        u[i] = t[t.size()-1-i];
    }
    return s.replace(n,m,u);
}


Compiler output:
/usr/bin/ld: /usr/lib/gcc/x86_64-linux-gnu/14/../../../x86_64-linux-gnu/Scrt1.o: in function `_start':
(.text+0x17): undefined reference to `main'
collect2: error: ld returned 1 exit status
Language: C++

#include <iostream>
#include <string>

using namespace std;

int main() {
	string str, o, p, m, str2;
	int i, q, a, b, j, x, c;
	cin >> str >> q;
	for (i = 0; i<q; i++) {
		cin >> o;
		if (o == "print") {
			cin >> a >> b;
			for (j = a; j <= b; j++)
				cout << str[j];
			cout << endl;
		}
		else if (o == "reverse") {
			cin >> a >> b;
			reverse(str.begin()+a,str.begin()+b+1);
		}
        else if (o == "replace") {
			cin >> a >> b >> p;
			str.replace(a,b-a+1,p);
		}
	}
}

Compiler output:
a.cc: In function 'int main()':
a.cc:20:25: error: 'reverse' was not declared in this scope
   20 |                         reverse(str.begin()+a,str.begin()+b+1);
      |                         ^~~~~~~
Language: C++

#include <iostream>
#include <string>
#include <algorhitm>

using namespace std;

int main() {
	string str, o, p, m, str2;
	int i, q, a, b, j, x, c;
	cin >> str >> q;
	for (i = 0; i<q; i++) {
		cin >> o;
		if (o == "print") {
			cin >> a >> b;
			for (j = a; j <= b; j++)
				cout << str[j];
			cout << endl;
		}
		else if (o == "reverse") {
			cin >> a >> b;
			reverse(str.begin()+a,str.begin()+b+1);
		}
        else if (o == "replace") {
			cin >> a >> b >> p;
			str.replace(a,b-a+1,p);
		}
	}
}

Compiler output:
a.cc:3:10: fatal error: algorhitm: No such file or directory
    3 | #include <algorhitm>
      |          ^~~~~~~~~~~
compilation terminated.
Language: C++

#include <iostream>
#include <string>

using namespace std;

int main()
{
	string str, cmd, p;
	int q, a, b;

	cin >> str >> q;

	for (int i = 0; i < q; i++){
		cin >> cmd;
		if (cmd == "print"){
			cin >> a >> b;
			cout << str.substr(a, b - a + 1) << endl;
		}
		else if (cmd == "reverse"){
			cin >> a >> b;
			p = str.substr(a, b - a + 1);
			reverse(p.begin(), p.end());
			str.replace(a, p.length(), p);
		}
		else if (cmd == "replace"){
			cin >> a >> b >> p;
			str.replace(a, p.length(), p);
		}
	}

	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:22:25: error: 'reverse' was not declared in this scope
   22 |                         reverse(p.begin(), p.end());
      |                         ^~~~~~~
Language: C++

#include<iostream>
#include<string>
#include<vector>
#include<cstdio>
using namespace std;
int main(){
string str;
cin>>str;
int N;cin>>N;
for(int i=0;i<N;i++){
	string m;cin>>m;
	if(m=="print"){
		int a,b;
		cin>>a>>b;
		cout<<str.substr(a,b)<<endl;
	}
	else if(m=="reverse"){
		int a,b;cin>>a>>b;
		string::iterator it;it=str.begin();
		reverse(it+a,it+b+1);
	}
	else if(m=="replace"){
		int a,b;string p;
		cin>>a>>b>>p;
			for(int i=0;a<=b;i++){
				str[a]=p[i];
				a++;		
		}
	}
}

return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:20:17: error: 'reverse' was not declared in this scope
   20 |                 reverse(it+a,it+b+1);
      |                 ^~~~~~~
Language: C++

#include<iostream>
#include<string>
using namespace std;
int main(){
	string str,com,word;
	int n,a,b;
	cin>>str>>n;
	for(int i=0;i<n;++i){
		cin>>com;
		switch(com[2]){
			case 'p':
				cin>>a>>b>>word;
				str=str.substr(0,a)+word+str.substr(b+1);
				break;
			case 'v':
				cin>>a>>b;
				str=str.substr(0,a)+str.substr(a,b-a+1).reverse()+str.substr(b+1);
				break;
			case 'i':
				cout<<str.substr(a,b-a+1)<<endl;
				break;
		}
	}
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:17:73: error: 'class std::__cxx11::basic_string<char>' has no member named 'reverse'; did you mean 'reserve'?
   17 |                                 str=str.substr(0,a)+str.substr(a,b-a+1).reverse()+str.substr(b+1);
      |                                                                         ^~~~~~~
      |                                                                         reserve
Language: C++

#include<iostream>
#include<string>
using namespace std;
int main(){
	string str,com,word;
	int n,a,b;
	cin>>str>>n;
	for(int i=0;i<n;++i){
		cin>>com;
		switch(com[2]){
			case 'p':
				cin>>a>>b>>word;
				str=str.substr(0,a)+word+str.substr(b+1);
				break;
			case 'v':
				cin>>a>>b;
				auto r=str.substr(a,b-a+1);
				str=str.substr(0,a)+string(r.rbegin(),r.rend())+str.substr(b+1);
				break;
			case 'i':
				cout<<str.substr(a,b-a+1)<<endl;
				break;
		}
	}
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:20:30: error: jump to case label
   20 |                         case 'i':
      |                              ^~~
a.cc:17:38: note:   crosses initialization of 'std::__cxx11::basic_string<char> r'
   17 |                                 auto r=str.substr(a,b-a+1);
      |                                      ^
Language: C++

#include<string>
#include<iostream>
using namespace std;

int main()
{
string str,str2;
string str3="";
string str4="";
int n,m,d;
cin>>str;
cin>>n;
for(int i=0;i<n;i++)
{
cin>>str2;
cin>>m>>d;
if(str2=="print"){
for(int j=m;j<=d;j++)
cout<<str[j];
}
cout<<endl;
}
else if(str2=="reverse"){
str4=str.substr(m,d-m+1);
str3=str4;
int wp=str4.size();
for(int j=0;j<wp;j++)
{
str[j]=str4[wp-j-1];
}



}
else if(str2=="replace"){
cin>>str3;
str.replace(m,d,str3);
}
str3="";
}


return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:23:1: error: 'else' without a previous 'if'
   23 | else if(str2=="reverse"){
      | ^~~~
a.cc: At global scope:
a.cc:43:1: error: expected unqualified-id before 'return'
   43 | return 0;
      | ^~~~~~
a.cc:44:1: error: expected declaration before '}' token
   44 | }
      | ^
Language: C++

#include <iostream>
#include <algorithm>
#include <vector>
#include <stack>
#include <queue>
#include <map>
#include <cmath>
#include <string>
#include <sstream>
#include <iomanip>
#include <complex>
using namespace std;

#define ll long long
#define vvi vector< vector<int> >
#define vi vector<int>
#define All(X) X.begin(),X.end()
#define FOR(i,a,b) for(int i=(int)(a);i<(int)(b);i++)
#define REP(i,n) for(int i=0;i<(int)(n);i++)
#define pb push_back
#define pii pair<int,int>
#define mp make_pair
ll gcd(ll a,ll b){return b?gcd(b,a%b):a;}
ll lcm(ll a,ll b){return a/gcd(a,b)*b;}

int main(){
	string str;
	int n;
	cin >> str >> n;
	REP(i,n){
		string op,p;
		int a,b;
		cin >> op;
        if (op == "print") {
            cin >> a >> b;
            cout << str.substr(a, b-a+1) << endl;
        }
        if (op == "reverse") {
            cin >> a >> b;
            reverse(str.begin()+a,str.begin()+b+1);
        }
        if (op == "replace") {
            cin >> a >> b >> p;
            t.replace(str.begin()+a, str.begin()+b+1, p);
        }
	}
}

Compiler output:
a.cc: In function 'int main()':
a.cc:44:13: error: 't' was not declared in this scope
   44 |             t.replace(str.begin()+a, str.begin()+b+1, p);
      |             ^
Language: C++

#include <iostream>
#include <string>
using namespace std;

int main(void){
	string str, instruction, temp;
	int a,b,q;

	cin >> str;
	cin >> q;

	for (int i = 0; i < q; i++){
		cin >> instruction >> a >> b;
		if (instruction == "replace"){
			cin >> temp;
			str.replace (a, (b-a)+1, temp);
		}
		else if (instruction == "reverse"){
			for (int i = a, j = b; i < floor((a + b) / 2)+1; i++, j--){
				char temp = str[j];
				str[j] = str[i];
				str[i] = temp;
			}
			cout << str;
		}
		else if (instruction == "print"){
			for (int i = a; i < b + 1; i++){
				cout << str[i];
			}
			cout << "\n";
		}
	}

	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:19:52: error: 'floor' was not declared in this scope
   19 |                         for (int i = a, j = b; i < floor((a + b) / 2)+1; i++, j--){
      |                                                    ^~~~~
Language: C++

#include <iostream>
using namespace std;

void print(string str, int a, int b)
{
    cout << str.substr(a, b + 1) << endl;
}

string reverse(string str, int a, int b)
{
    string left = str.substr(0, a);
    string middle = str.substr(a, b + 1);
    string right = str.substr(b + 1, str.size());

    reverse(middle.begin(), middle.end());

    return left + middle + right;
}

string replace(string str, int a, int b, string p)
{
    string left = str.substr(0, a);
    string middle = str.substr(a + 1, b);
    string right = str.substr(b + 1, str.size());

    return left + p + right;
}

int main()
{
    string str, func;
    int n;

    cin >> str >> n;

    for (int i = 0; i < n; i++) {
        cin >> func;

        if (!func.compare("reverse")) {
            int a, b;

            cin >> a >> b;

            str = reverse(str, a, b);
        } else if (!func.compare("replace")) {
            int a, b;
            string s;

            cin >> a >> b >> s;

            str = replace(str, a, b, s);
        } else if (!func.compare("print")) {
            int a, b;

            cin >> a >> b;

            print(str, a, b);
        }
    }

    return 0;
}

Compiler output:
a.cc: In function 'std::string reverse(std::string, int, int)':
a.cc:15:25: error: could not convert 'middle.std::__cxx11::basic_string<char>::begin()' from 'std::__cxx11::basic_string<char>::iterator' to 'std::string' {aka 'std::__cxx11::basic_string<char>'}
   15 |     reverse(middle.begin(), middle.end());
      |             ~~~~~~~~~~~~^~
      |                         |
      |                         std::__cxx11::basic_string<char>::iterator
Language: C++

#include <iostream>
#include <string>
using namespace std;

void print(string str, int a, int b)
{
    cout << str.substr(a, b + 1) << endl;
}

string reverse(string str, int a, int b)
{
    string left = str.substr(0, a);
    string middle = str.substr(a, b + 1);
    string right = str.substr(b + 1, str.size());

    reverse(middle.begin(), middle.end());

    return left + middle + right;
}

string replace(string str, int a, int b, string p)
{
    string left = str.substr(0, a);
    string middle = str.substr(a + 1, b);
    string right = str.substr(b + 1, str.size());

    return left + p + right;
}

int main()
{
    string str, func;
    int n;

    cin >> str >> n;

    for (int i = 0; i < n; i++) {
        cin >> func;

        if (!func.compare("reverse")) {
            int a, b;

            cin >> a >> b;

            str = reverse(str, a, b);
        } else if (!func.compare("replace")) {
            int a, b;
            string s;

            cin >> a >> b >> s;

            str = replace(str, a, b, s);
        } else if (!func.compare("print")) {
            int a, b;

            cin >> a >> b;

            print(str, a, b);
        }
    }

    return 0;
}

Compiler output:
a.cc: In function 'std::string reverse(std::string, int, int)':
a.cc:16:25: error: could not convert 'middle.std::__cxx11::basic_string<char>::begin()' from 'std::__cxx11::basic_string<char>::iterator' to 'std::string' {aka 'std::__cxx11::basic_string<char>'}
   16 |     reverse(middle.begin(), middle.end());
      |             ~~~~~~~~~~~~^~
      |                         |
      |                         std::__cxx11::basic_string<char>::iterator
Language: C++

//
//  main.cpp
//  ITP1_9-D
//
//  Created by Saicj on 2015/08/04.
//  Copyright (c) 2015??´ saicj. All rights reserved.
//

#include <iostream>
#include <vector>
#include <string>
#include <codecvt>

using namespace std;


int main(int argc, const char * argv[]) {

    string str;
    int count;
    
    cin >> str;
    cin >> count;
    
    string order;
    int a;
    int b;
    string instead;

    
    for (int i = 0; i < count; i++) {
        
        cin >> order >> a >> b;
        
        if (order == "replace") {
            
            cin >> instead;
            
            str = str.replace(a, instead.length(), instead);
            
//            cout  << str << endl;
            
        }else if (order == "reverse"){
            
            string tempStr = str.substr(a,(b-a)+1);
            reverse(tempStr.begin(), tempStr.end());
            
//            cout << tempStr.length() << endl;
            
             str = str.replace(a, tempStr.length(), tempStr);
//            cout  << str << endl;
            
            
        }else if (order == "print"){
            
            cout << str.substr(a, b) << endl;
        }
    }

    
    return 0;
}

Compiler output:
a.cc: In function 'int main(int, const char**)':
a.cc:46:13: error: 'reverse' was not declared in this scope
   46 |             reverse(tempStr.begin(), tempStr.end());
      |             ^~~~~~~
Language: C++

//
//  main.cpp
//  ITP1_9-D
//
//  Created by Saicj on 2015/08/04.
//  Copyright (c) 2015??´ saicj. All rights reserved.
//

#include <iostream>
#include <vector>
#include <string>

using namespace std;


int main(int argc, const char * argv[]) {

    string str;
    int count;
    
    cin >> str;
    cin >> count;
    
    string order;
    int a;
    int b;
    string instead;

    
    for (int i = 0; i < count; i++) {
        
        cin >> order >> a >> b;
        
        if (order == "replace") {
            
            cin >> instead;
            
            str = str.replace(a, instead.length(), instead);
            
        }else if (order == "reverse"){
            
            string tempStr = str.substr(a,(b-a)+1);
            reverse(tempStr.begin(), tempStr.end());
            
             str = str.replace(a, tempStr.length(), tempStr);
            
        }else if (order == "print"){
            
            cout << str.substr(a, b) << endl;
        }
    }

    
    return 0;
}

Compiler output:
a.cc: In function 'int main(int, const char**)':
a.cc:43:13: error: 'reverse' was not declared in this scope
   43 |             reverse(tempStr.begin(), tempStr.end());
      |             ^~~~~~~
Language: C++

//
//  main.cpp
//  ITP1_9-D
//
//  Created by Saicj on 2015/08/04.
//  Copyright (c) 2015??´ saicj. All rights reserved.
//

#include <iostream>
#include <vector>
#include <string>
#include <codecvt>

using namespace std;


int main(int argc, const char * argv[]) {

    string str;
    int count;
    
    cin >> str;
    cin >> count;
    
    string order;
    int a;
    int b;
    string instead;

    
    for (int i = 0; i < count; i++) {
        
        cin >> order >> a >> b;
        
        if (order == "replace") {
            
            cin >> instead;
            
            str = str.replace(a, instead.length(), instead);
            
        }else if (order == "reverse"){
            
            string tempStr = str.substr(a,(b-a)+1);
            reverse(tempStr.begin(), tempStr.end());
            
             str = str.replace(a, tempStr.length(), tempStr);
            
        }else if (order == "print"){
            
            cout << str.substr(a, b) << endl;
        }
    }

    
    return 0;
}

Compiler output:
a.cc: In function 'int main(int, const char**)':
a.cc:44:13: error: 'reverse' was not declared in this scope
   44 |             reverse(tempStr.begin(), tempStr.end());
      |             ^~~~~~~
Language: C++

using System;
using System.Linq;

public class Test
{
	public static void Main( )
	{
		string str = Console.ReadLine();
		int q = int.Parse( Console.ReadLine() );
		for( var i=0; i<q; i++ ) {
			string[] cmds = Console.ReadLine().Split( ' ' );
			int s = int.Parse( cmds[1] );
			int e = int.Parse( cmds[2] );
			int len = e-s+1;
			if( "print" == cmds[0] ) {
				Console.WriteLine( str.Substring( s, len ) );
			} else if( "reverse" == cmds[0] ) {
				string t = new string( str.Substring( s, len ).Reverse().ToArray() );
				str = str.Substring( 0, s )+t+str.Substring( e+1 );
			} else if( "replace" == cmds[0] ) {
				str = str.Substring( 0, s )+cmds[3]+str.Substring( e+1 );
			}
		}
	}
}

Compiler output:
a.cc:1:7: error: expected nested-name-specifier before 'System'
    1 | using System;
      |       ^~~~~~
a.cc:2:7: error: expected nested-name-specifier before 'System'
    2 | using System.Linq;
      |       ^~~~~~
a.cc:4:1: error: expected unqualified-id before 'public'
    4 | public class Test
      | ^~~~~~
Language: C++

#include <cstdio>
#include <string>
using namespace std;
int main(){
  char str[1000];
  int q;
  scanf("%s", str);
  scanf("%d", &q);
  for(int i = 0; i < q; i++){
    char cmd[10];
    int a, b;
    char  p[1000];
    scanf("%s %d %d", cmd, &a, &b);
    if(strcmp(cmd, "replace") == 0){
      scanf("%s", p);
      for(int j = a; j <= b; j++)
	str[j] = p[j - a];
    }
    else if(strcmp(cmd, "reverse") == 0){
      char r[1000];
      for(int j = a; j <= b; j++)
	r[j - a] = str[j];
      for(j = a; j <= b; j++)
	str[j] = r[b - a - j];
    }
    else if(strcmp(cmd, "print") == 0){
      for(int j = a; j <= b; j++)
	printf("%c", &str[j]);
      printf("\n");
    }
  }
}

Compiler output:
a.cc: In function 'int main()':
a.cc:14:8: error: 'strcmp' was not declared in this scope
   14 |     if(strcmp(cmd, "replace") == 0){
      |        ^~~~~~
a.cc:3:1: note: 'strcmp' is defined in header '<cstring>'; this is probably fixable by adding '#include <cstring>'
    2 | #include <string>
  +++ |+#include <cstring>
    3 | using namespace std;
a.cc:23:11: error: 'j' was not declared in this scope
   23 |       for(j = a; j <= b; j++)
      |           ^
Language: C++

#include <cstdio>
#include <cstring>
using namespace std;
int main(){
  char str[1000];
  int q;
  scanf("%s", str);
  scanf("%d", &q);
  for(int i = 0; i < q; i++){
    char cmd[10];
    int a, b;
    char  p[1000];
    scanf("%s %d %d", cmd, &a, &b);
    if(strcmp(cmd, "replace") == 0){
      scanf("%s", p);
      for(int j = a; j <= b; j++)
	str[j] = p[j - a];
    }
    else if(strcmp(cmd, "reverse") == 0){
      char r[1000];
      for(int j = a; j <= b; j++)
	r[j - a] = str[j];
      for(j = a; j <= b; j++)
	str[j] = r[b - a - j];
    }
    else if(strcmp(cmd, "print") == 0){
      for(int j = a; j <= b; j++)
	printf("%c", &str[j]);
      printf("\n");
    }
  }
}

Compiler output:
a.cc: In function 'int main()':
a.cc:23:11: error: 'j' was not declared in this scope
   23 |       for(j = a; j <= b; j++)
      |           ^