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

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

int main(){
  string s1, s2, s3;
  cin >> s1 >> s2 >> s3;
  
  transform(s1.begin(), s1.end(), s1.begin(), toupper);
  transform(s2.begin(), s2.end(), s2.begin(), toupper);
  transform(s3.begin(), s3.end(), s3.begin(), toupper);

  cout << s1[0] << s2[0] << s3[0] << endl; 
  return 0;
}



Compiler output:
a.cc: In function 'int main()':
a.cc:9:3: error: 'transform' was not declared in this scope
    9 |   transform(s1.begin(), s1.end(), s1.begin(), toupper);
      |   ^~~~~~~~~
Language: C++

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

int main(){
  string s1, s2, s3;
  cin >> s1 >> s2 >> s3;
  
  transform(s1.begin(), s1.end(), s1.begin(), ::toupper);
  transform(s2.begin(), s2.end(), s2.begin(), ::toupper);
  transform(s3.begin(), s3.end(), s3.begin(), ::toupper);

  cout << s1[0] << s2[0] << s3[0] << endl; 
  return 0;
}



Compiler output:
a.cc: In function 'int main()':
a.cc:9:3: error: 'transform' was not declared in this scope
    9 |   transform(s1.begin(), s1.end(), s1.begin(), ::toupper);
      |   ^~~~~~~~~
Language: C++

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

int main(){
  string s1, s2, s3;
  cin >> s1 >> s2 >> s3;
  
  transform(s1.begin(), s1.end(), s1.begin(), ::toupper)
  transform(s2.begin(), s2.end(), s2.begin(), ::toupper)
  transform(s3.begin(), s3.end(), s3.begin(), ::toupper)

  cout << s1[0] << s2[0] << s3[0] << endl; 
  return 0;
}



Compiler output:
a.cc: In function 'int main()':
a.cc:9:3: error: 'transform' was not declared in this scope
    9 |   transform(s1.begin(), s1.end(), s1.begin(), ::toupper)
      |   ^~~~~~~~~
Language: C++

#include <iostream>
#include <string>

int main(){
  string s1, s2, s3;
  cin >> s1 >> s2 >> s3;
  
  cout << s1[0] - 32;
  cout << s2[0] - 32;
  cout << s3[0] - 32 << endl;
  
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:5:3: error: 'string' was not declared in this scope
    5 |   string s1, s2, s3;
      |   ^~~~~~
a.cc:5:3: note: suggested alternatives:
In file included from /usr/include/c++/14/iosfwd:41,
                 from /usr/include/c++/14/ios:40,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41,
                 from a.cc:1:
/usr/include/c++/14/bits/stringfwd.h:77:33: note:   'std::string'
   77 |   typedef basic_string<char>    string;
      |                                 ^~~~~~
In file included from /usr/include/c++/14/bits/locale_classes.h:40,
                 from /usr/include/c++/14/bits/ios_base.h:41,
                 from /usr/include/c++/14/ios:44:
/usr/include/c++/14/string:76:11: note:   'std::pmr::string'
   76 |     using string    = basic_string<char>;
      |           ^~~~~~
a.cc:6:3: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    6 |   cin >> s1 >> s2 >> s3;
      |   ^~~
      |   std::cin
/usr/include/c++/14/iostream:62:18: note: 'std::cin' declared here
   62 |   extern istream cin;           ///< Linked to standard input
      |                  ^~~
a.cc:6:10: error: 's1' was not declared in this scope
    6 |   cin >> s1 >> s2 >> s3;
      |          ^~
a.cc:6:16: error: 's2' was not declared in this scope
    6 |   cin >> s1 >> s2 >> s3;
      |                ^~
a.cc:6:22: error: 's3' was not declared in this scope
    6 |   cin >> s1 >> s2 >> s3;
      |                      ^~
a.cc:8:3: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
    8 |   cout << s1[0] - 32;
      |   ^~~~
      |   std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
a.cc:10:25: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   10 |   cout << s3[0] - 32 << endl;
      |                         ^~~~
      |                         std::endl
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~
Language: C++

#include <stdio.h>
#include<string.h>
int main()
{
    int k;
    char s[100],i=0;
    gets(s);
    k=strlen(s);
    printf("%c",s[0]-32);
   for(i;i<k;i++)
   {
     if(s[i]==' ')
      printf("%c",s[i+1]-32);
   }
    return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:7:5: error: 'gets' was not declared in this scope; did you mean 'getw'?
    7 |     gets(s);
      |     ^~~~
      |     getw
Language: Java

import java.util.*;

public class Main{
  public static void main(String[] args){
    Scanner sc=new Scanner(System.in);
    char[] a=sc.next().toCharArray();
    char[] b=sc.next().toCharArray();
    char[] c=sc.next().toCharArray();
    a[0]=String.valueOf(a[0]).toUpperCase().toChar();
    b[0]=String.valueOf(b[0]).toUpperCase().toChar();
    c[0]=String.valueOf(c[0]).toUpperCase().toChar();
    char[] d={a[0],b[0],c[0]};
    String s=String.valueOf(d);
    System.out.println(s);
  }
}

Compiler output:
Main.java:9: error: cannot find symbol
    a[0]=String.valueOf(a[0]).toUpperCase().toChar();
                                           ^
  symbol:   method toChar()
  location: class String
Main.java:10: error: cannot find symbol
    b[0]=String.valueOf(b[0]).toUpperCase().toChar();
                                           ^
  symbol:   method toChar()
  location: class String
Main.java:11: error: cannot find symbol
    c[0]=String.valueOf(c[0]).toUpperCase().toChar();
                                           ^
  symbol:   method toChar()
  location: class String
3 errors
Language: Java

import java.util.*;

public class Main{
  public static void main(String[] args){
    Scanner sc=new Scanner(System.in);
    char[] a=sc.next().toCharArray();
    char[] b=sc.next().toCharArray();
    char[] c=sc.next().toCharArray();
    a[0]=String.valueOf(a[0]).toUpperCase().toChar;
    b[0]=String.valueOf(b[0]).toUpperCase().toChar;
    c[0]=String.valueOf(c[0]).toUpperCase().toChar;
    char[] d={a[0],b[0],c[0]};
    String s=String.valueOf(d);
    System.out.println(s);
  }
}

Compiler output:
Main.java:9: error: cannot find symbol
    a[0]=String.valueOf(a[0]).toUpperCase().toChar;
                                           ^
  symbol:   variable toChar
  location: class String
Main.java:10: error: cannot find symbol
    b[0]=String.valueOf(b[0]).toUpperCase().toChar;
                                           ^
  symbol:   variable toChar
  location: class String
Main.java:11: error: cannot find symbol
    c[0]=String.valueOf(c[0]).toUpperCase().toChar;
                                           ^
  symbol:   variable toChar
  location: class String
3 errors
Language: Java

import java.util.*;

public class Main{
  public static void main(String[] args){
    Scanner sc=new Scanner(System.in);
    char[] a=sc.next().toCharArray();
    char[] b=sc.next().toCharArray();
    char[] c=sc.next().toCharArray();
    a[0]=a[0].toUpperCase();
    b[0]=b[0].toUpperCase();
    c[0]=c[0].toUpperCase();
    char[] d={a[0],a[1],a[2]};
    String s=String.valueOf(d);
    System.out.println(s);
  }
}

Compiler output:
Main.java:9: error: char cannot be dereferenced
    a[0]=a[0].toUpperCase();
             ^
Main.java:10: error: char cannot be dereferenced
    b[0]=b[0].toUpperCase();
             ^
Main.java:11: error: char cannot be dereferenced
    c[0]=c[0].toUpperCase();
             ^
3 errors
Language: Java

import java.util.*;

public class Main{
  public static void main(String[] args){
    Scanner sc=new Scanner(System.in);
    char[] a=sc.next().toCharArray();
    char[] b=sc.next().toCharArray();
    char[] c=sc.next().toCharArray();
    a[0]=a[0].toUpperCase();
    b[0]=b[0].toUpperCase();
    c[0]=c[0].toUpperCase();
    String s=String.valueOf({a[0],a[1],a[2]});
  }
}

Compiler output:
Main.java:12: error: illegal start of expression
    String s=String.valueOf({a[0],a[1],a[2]});
                            ^
Main.java:12: error: not a statement
    String s=String.valueOf({a[0],a[1],a[2]});
                              ^
Main.java:12: error: ';' expected
    String s=String.valueOf({a[0],a[1],a[2]});
                                 ^
Main.java:12: error: not a statement
    String s=String.valueOf({a[0],a[1],a[2]});
                                   ^
Main.java:12: error: ';' expected
    String s=String.valueOf({a[0],a[1],a[2]});
                                      ^
Main.java:12: error: not a statement
    String s=String.valueOf({a[0],a[1],a[2]});
                                        ^
Main.java:12: error: ';' expected
    String s=String.valueOf({a[0],a[1],a[2]});
                                           ^
Main.java:12: error: illegal start of expression
    String s=String.valueOf({a[0],a[1],a[2]});
                                            ^
8 errors
Language: Java

import java.util.*;

public class Main{
  public static void main(String[] args){
    Scanner sc=new Scanner(System.in);
    char[] a=sc.next().toCharArray();
    char[] b=sc.next().toCharArray();
    char[] c=sc.next().toCharArray();
    a[0]=a[0].toUpperCase();
    b[0]=b[0].toUpperCase();
    c[0]=c[0].toUpperCase();
    String s=String.value of({a[0],a[1],a[2]});
  }
}

Compiler output:
Main.java:12: error: ';' expected
    String s=String.value of({a[0],a[1],a[2]});
                         ^
Main.java:12: error: illegal start of expression
    String s=String.value of({a[0],a[1],a[2]});
                             ^
Main.java:12: error: not a statement
    String s=String.value of({a[0],a[1],a[2]});
                               ^
Main.java:12: error: ';' expected
    String s=String.value of({a[0],a[1],a[2]});
                                  ^
Main.java:12: error: not a statement
    String s=String.value of({a[0],a[1],a[2]});
                                    ^
Main.java:12: error: ';' expected
    String s=String.value of({a[0],a[1],a[2]});
                                       ^
Main.java:12: error: not a statement
    String s=String.value of({a[0],a[1],a[2]});
                                         ^
Main.java:12: error: ';' expected
    String s=String.value of({a[0],a[1],a[2]});
                                            ^
Main.java:12: error: illegal start of expression
    String s=String.value of({a[0],a[1],a[2]});
                                             ^
9 errors
Language: Java

import java.util.*;

public class Main{
  public static void main(String[] args){
    Scanner sc=new Scanner(System.in);
    String[] s=sc.next().split(" ");
    for(int i=0;i<3;i++){
      char c=s[i].charAt(0);
      System.out.print(String.valueOf(c).toUpperCase());
    }
    System.out.print(\n);
  }
}

Compiler output:
Main.java:11: error: illegal character: '\'
    System.out.print(\n);
                     ^
Main.java:11: error: not a statement
    System.out.print(\n);
                      ^
Main.java:11: error: ';' expected
    System.out.print(\n);
                       ^
3 errors
Language: Java

import java.util.*;

public class Main{
  public static void main(String[] args){
    Scanner sc=new Scanner(System.in);
    String[] s=sc.next().split(" ");
    for(int i=0;i<3,i++){
      s[i]=s[i].substring(0,1).toUpperCase();
    }
    System.out.println(s[0]+s[1]+s[2]);
  }
}

Compiler output:
Main.java:7: error: ';' expected
    for(int i=0;i<3,i++){
                   ^
1 error
Language: C++

#include <bits/stdc++.h>

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

using namespace std;

int main(){
	string a,b,c; cin>>a>>b>>c>>;
	cout<<toupper(a[0])+toupper(b[0])+toupper(c[0])<<endl;

	return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:8:37: error: expected primary-expression before ';' token
    8 |         string a,b,c; cin>>a>>b>>c>>;
      |                                     ^
Language: C

#include<stdio.h>
#include<string.h>
#include<algorithm>
using namespace std;
int main()
{
	char a[10101],b[10100];
	gets(a);
	int k=0;
	int l=strlen(a);
	for(int i=0;i<l;i++)
	{
		if(i==0)
		b[k++]=a[i]-32;
		else if(a[i]==' '&&a[i+1]!=' ')
		b[k++]=a[i+1]-32;
	}
	printf("%s\n",b);
	return 0;
}

Compiler output:
main.c:3:9: fatal error: algorithm: No such file or directory
    3 | #include<algorithm>
      |         ^~~~~~~~~~~
compilation terminated.
Language: C++

#include<stdio.h>
#include<string.h>
#include<algorithm>
using namespace std;
int main()
{
	char a[10101],b[10100];
	gets(a);
	int k=0;
	int l=strlen(a);
	for(int i=0;i<l;i++)
	{
		if(i==0)
		b[k++]=a[i]-32;
		else if(a[i]==' '&&a[i+1]!=' ')
		b[k++]=a[i+1]-32;
	}
	printf("%s\n",b);
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:8:9: error: 'gets' was not declared in this scope; did you mean 'getw'?
    8 |         gets(a);
      |         ^~~~
      |         getw
Language: C++

#include <iostream>
#include <vector>
#include <algorithm>
#include <string.h>
#include <iomanip>
#include <map>
#include <cstdlib>
#include <cctype>
using namespace std;
char toupr(char c); 
int main(){
string a,b,c;
cin >> a>>b>>c;
char d,e,f;
d =a[0];
e =b[0];
f =c[0];
cout << tolowr(d) <<tolowr(e) << tolowr(f) << endl;

    return 0;

}
char toupr(char c) {
  return (c - 0x20);
}



Compiler output:
a.cc: In function 'int main()':
a.cc:18:9: error: 'tolowr' was not declared in this scope; did you mean 'tolower'?
   18 | cout << tolowr(d) <<tolowr(e) << tolowr(f) << endl;
      |         ^~~~~~
      |         tolower
Language: C++

#include <iostream>
#include <vector>
#include <algorithm>
#include <string.h>
#include <iomanip>
#include <map>
#include <cstdlib>
#include <cctype>
using namespace std;
char toupr(char c); 
int main(){
string a,b,c;
cin >> a>>b>>c;
char d,e,f;
d =a[0];
e =b[0];
f =c[0];
cout << tolowr(d) <<tolowr(e) << tolowr(f) << endl;

    return 0;

}


Compiler output:
a.cc: In function 'int main()':
a.cc:18:9: error: 'tolowr' was not declared in this scope; did you mean 'tolower'?
   18 | cout << tolowr(d) <<tolowr(e) << tolowr(f) << endl;
      |         ^~~~~~
      |         tolower
Language: C++

#include <iostream>
#include <vector>
#include <algorithm>
#include <string.h>
#include <iomanip>
#include <map>
#include <cstdlib>
#include <cctype>
using namespace std;
int main(){
string a,b,c;
cin >> a>>b>>c;
cout << a[0]+dif <<b[0]+dif << c[0] +dif;
    return 0;

}


Compiler output:
a.cc: In function 'int main()':
a.cc:13:14: error: 'dif' was not declared in this scope; did you mean 'div'?
   13 | cout << a[0]+dif <<b[0]+dif << c[0] +dif;
      |              ^~~
      |              div
Language: C++

vinclude<bits/stdc++.h>
#define rep(i,n) for(int i=0; i<(n); i++)
#define reps(i,n) for(int i=1; i<(n); i++)
#define pii pair<int,int>
#define all(x) (x).begin(), (x).end()
#define int long long
#define setout(n,x) setw(n) << setfill(x)
#define Fixed fixed << setprecision(10)
const int INF = 0x3f3f3f3f;
const long long LINF = 0x3f3f3f3f3f3f3f3fLL;
const long long mod = 1000000007;
using namespace std;
long long h[10000010],x[10000010];
signed main(){
      
  cin.tie(0);
  ios::sync_with_stdio(false);
  
  string s1,s2,s3;
  cin>>s1>>s2>>s3;

  cout<<s1[0]-('a'-'A')<<s2[0]-('a'-'A')<<s3[0]-('a'-'A')<<'\n';
}

Compiler output:
a.cc:1:1: error: 'vinclude' does not name a type
    1 | vinclude<bits/stdc++.h>
      | ^~~~~~~~
a.cc: In function 'int main()':
a.cc:16:3: error: 'cin' was not declared in this scope
   16 |   cin.tie(0);
      |   ^~~
a.cc:1:1: note: 'std::cin' is defined in header '<iostream>'; this is probably fixable by adding '#include <iostream>'
  +++ |+#include <iostream>
    1 | vinclude<bits/stdc++.h>
a.cc:17:3: error: 'ios' has not been declared
   17 |   ios::sync_with_stdio(false);
      |   ^~~
a.cc:19:3: error: 'string' was not declared in this scope
   19 |   string s1,s2,s3;
      |   ^~~~~~
a.cc:1:1: note: 'std::string' is defined in header '<string>'; this is probably fixable by adding '#include <string>'
  +++ |+#include <string>
    1 | vinclude<bits/stdc++.h>
a.cc:20:8: error: 's1' was not declared in this scope
   20 |   cin>>s1>>s2>>s3;
      |        ^~
a.cc:20:12: error: 's2' was not declared in this scope
   20 |   cin>>s1>>s2>>s3;
      |            ^~
a.cc:20:16: error: 's3' was not declared in this scope
   20 |   cin>>s1>>s2>>s3;
      |                ^~
a.cc:22:3: error: 'cout' was not declared in this scope
   22 |   cout<<s1[0]-('a'-'A')<<s2[0]-('a'-'A')<<s3[0]-('a'-'A')<<'\n';
      |   ^~~~
a.cc:22:3: note: 'std::cout' is defined in header '<iostream>'; this is probably fixable by adding '#include <iostream>'
Language: C++

#include<bits/stdc++.h>
using namespace std ;
int main()
  { 
   string a,b,c;
   cin>>a>>b>>c;
   cout<<a[0]-32<<b[0]-32<<c[0]-32<<endl;
  }#include<bits/stdc++.h>
using namespace std ;
int main()
  { 
   string a,b,c;
   cin>>a>>b>>c;
   transform(a.begin(),a.end(),a.begin(),::toupper); 
  transform(b.begin(),b.end(),b.begin(),::toupper); 
 transform(c.begin(),c.end(),c.begin(),::toupper); 

   cout<<a[0]<<b[0]<<c[0]<<endl;
}

Compiler output:
a.cc:8:4: error: stray '#' in program
    8 |   }#include<bits/stdc++.h>
      |    ^
a.cc:8:5: error: 'include' does not name a type
    8 |   }#include<bits/stdc++.h>
      |     ^~~~~~~
a.cc:10:5: error: redefinition of 'int main()'
   10 | int main()
      |     ^~~~
a.cc:3:5: note: 'int main()' previously defined here
    3 | int main()
      |     ^~~~
Language: C++

#include <bits/stdc++.h>
using namespace std;
 
int main() {
  string a, b, c;
  cin >> a >> b >>c;
  string ans;
  ans += (char)(a[0]-'a'+'A')
  ans += (char)(b[0]-'a'+'A')
  ans += (char)(c[0]-'a'+'A')
  cout << ans << endl;
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:8:30: error: expected ';' before 'ans'
    8 |   ans += (char)(a[0]-'a'+'A')
      |                              ^
      |                              ;
    9 |   ans += (char)(b[0]-'a'+'A')
      |   ~~~
Language: C++

#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<n;++i)
using namespace std;
typedef unsigned long long ull;

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);

    vector<string> s[3];
    rep(i, 0, 3) cin >> s[i];
    rep(i, 0, 3) {
      cout << (s[i][0] + 0x20);
    }
}


Compiler output:
a.cc:11:16: error: macro "rep" passed 3 arguments, but takes just 2
   11 |     rep(i, 0, 3) cin >> s[i];
      |                ^
a.cc:2:9: note: macro "rep" defined here
    2 | #define rep(i,n) for(int i=0;i<n;++i)
      |         ^~~
a.cc:12:16: error: macro "rep" passed 3 arguments, but takes just 2
   12 |     rep(i, 0, 3) {
      |                ^
a.cc:2:9: note: macro "rep" defined here
    2 | #define rep(i,n) for(int i=0;i<n;++i)
      |         ^~~
a.cc: In function 'int main()':
a.cc:11:5: error: 'rep' was not declared in this scope
   11 |     rep(i, 0, 3) cin >> s[i];
      |     ^~~
a.cc:12:8: error: expected ';' before '{' token
   12 |     rep(i, 0, 3) {
      |        ^         ~
      |        ;
Language: C++

#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<n;++i)
using namespace std;
typedef unsigned long long ull;

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);

    vector<string> s[3];
    rep(i, 0, 3) cin >> s[i];
    rep(i, 0, 3) {
      cout << (s[i] + 0x20);
    }
}


Compiler output:
a.cc:11:16: error: macro "rep" passed 3 arguments, but takes just 2
   11 |     rep(i, 0, 3) cin >> s[i];
      |                ^
a.cc:2:9: note: macro "rep" defined here
    2 | #define rep(i,n) for(int i=0;i<n;++i)
      |         ^~~
a.cc:12:16: error: macro "rep" passed 3 arguments, but takes just 2
   12 |     rep(i, 0, 3) {
      |                ^
a.cc:2:9: note: macro "rep" defined here
    2 | #define rep(i,n) for(int i=0;i<n;++i)
      |         ^~~
a.cc: In function 'int main()':
a.cc:11:5: error: 'rep' was not declared in this scope
   11 |     rep(i, 0, 3) cin >> s[i];
      |     ^~~
a.cc:12:8: error: expected ';' before '{' token
   12 |     rep(i, 0, 3) {
      |        ^         ~
      |        ;
Language: C++

#include<iostream>
#include<string>
using namespace;
int main(){
  string s1, s2, s3;
  cin >> s1 >> s2 >> s3;
   
  cout << s1[0] - 0x20 << " " << s2[0] - 0x20 << " " << s3[0] - 0x20 ;


  return 0;
}


Compiler output:
a.cc:3:16: error: expected identifier before ';' token
    3 | using namespace;
      |                ^
a.cc: In function 'int main()':
a.cc:5:3: error: 'string' was not declared in this scope
    5 |   string s1, s2, s3;
      |   ^~~~~~
a.cc:5:3: note: suggested alternatives:
In file included from /usr/include/c++/14/iosfwd:41,
                 from /usr/include/c++/14/ios:40,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41,
                 from a.cc:1:
/usr/include/c++/14/bits/stringfwd.h:77:33: note:   'std::string'
   77 |   typedef basic_string<char>    string;
      |                                 ^~~~~~
In file included from /usr/include/c++/14/bits/locale_classes.h:40,
                 from /usr/include/c++/14/bits/ios_base.h:41,
                 from /usr/include/c++/14/ios:44:
/usr/include/c++/14/string:76:11: note:   'std::pmr::string'
   76 |     using string    = basic_string<char>;
      |           ^~~~~~
a.cc:6:3: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    6 |   cin >> s1 >> s2 >> s3;
      |   ^~~
      |   std::cin
/usr/include/c++/14/iostream:62:18: note: 'std::cin' declared here
   62 |   extern istream cin;           ///< Linked to standard input
      |                  ^~~
a.cc:6:10: error: 's1' was not declared in this scope
    6 |   cin >> s1 >> s2 >> s3;
      |          ^~
a.cc:6:16: error: 's2' was not declared in this scope
    6 |   cin >> s1 >> s2 >> s3;
      |                ^~
a.cc:6:22: error: 's3' was not declared in this scope
    6 |   cin >> s1 >> s2 >> s3;
      |                      ^~
a.cc:8:3: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
    8 |   cout << s1[0] - 0x20 << " " << s2[0] - 0x20 << " " << s3[0] - 0x20 ;
      |   ^~~~
      |   std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
Language: C++

#include<iostream>
#include<string>
using namespace;
int main(){
  string s1, s2, s3;
  cin >> s1 >> s2 >> s3;
   
  cout << s1 - 0x20 << " " << s2 - 0x20 << " " << s3 - 0x20 ;


  return 0;
}

Compiler output:
a.cc:3:16: error: expected identifier before ';' token
    3 | using namespace;
      |                ^
a.cc: In function 'int main()':
a.cc:5:3: error: 'string' was not declared in this scope
    5 |   string s1, s2, s3;
      |   ^~~~~~
a.cc:5:3: note: suggested alternatives:
In file included from /usr/include/c++/14/iosfwd:41,
                 from /usr/include/c++/14/ios:40,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41,
                 from a.cc:1:
/usr/include/c++/14/bits/stringfwd.h:77:33: note:   'std::string'
   77 |   typedef basic_string<char>    string;
      |                                 ^~~~~~
In file included from /usr/include/c++/14/bits/locale_classes.h:40,
                 from /usr/include/c++/14/bits/ios_base.h:41,
                 from /usr/include/c++/14/ios:44:
/usr/include/c++/14/string:76:11: note:   'std::pmr::string'
   76 |     using string    = basic_string<char>;
      |           ^~~~~~
a.cc:6:3: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    6 |   cin >> s1 >> s2 >> s3;
      |   ^~~
      |   std::cin
/usr/include/c++/14/iostream:62:18: note: 'std::cin' declared here
   62 |   extern istream cin;           ///< Linked to standard input
      |                  ^~~
a.cc:6:10: error: 's1' was not declared in this scope
    6 |   cin >> s1 >> s2 >> s3;
      |          ^~
a.cc:6:16: error: 's2' was not declared in this scope
    6 |   cin >> s1 >> s2 >> s3;
      |                ^~
a.cc:6:22: error: 's3' was not declared in this scope
    6 |   cin >> s1 >> s2 >> s3;
      |                      ^~
a.cc:8:3: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
    8 |   cout << s1 - 0x20 << " " << s2 - 0x20 << " " << s3 - 0x20 ;
      |   ^~~~
      |   std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
Language: C++

#include <bits/stdc++.h>
#include <string>

using namespace std;

int main() {

  string S; string T; string U;
  cin>>S>>T>>U;
  transform(S.at(0), T.at(0),U.at(0) ,::toupper);
  cout<<S.at(0)<<T.at(0)<<U.at(0)<<endl;
}

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:1:
/usr/include/c++/14/bits/stl_algo.h: In instantiation of '_OIter std::transform(_IIter, _IIter, _OIter, _UnaryOperation) [with _IIter = char; _OIter = char; _UnaryOperation = int (*)(int) noexcept]':
a.cc:10:12:   required from here
   10 |   transform(S.at(0), T.at(0),U.at(0) ,::toupper);
      |   ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:4220:9: error: invalid type argument of unary '*' (have 'char')
 4220 |         *__result = __unary_op(*__first);
      |         ^~~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:4220:32: error: invalid type argument of unary '*' (have 'char')
 4220 |         *__result = __unary_op(*__first);
      |                                ^~~~~~~~
Language: C++

#include <bits/stdc++.h>
#include <string>
#include <algorithm>
#include <cctype>
#include <cstdio>
using namespace std;

int main() {

  string S; string T; string U;
  cin>>S>>T>>U;
  transform(S.at(0), T.at(0),U.at(0) ,::toupper);
  cout<<S.at(0)<<T.at(0)<<U.at(0)<<endl;
}

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:1:
/usr/include/c++/14/bits/stl_algo.h: In instantiation of '_OIter std::transform(_IIter, _IIter, _OIter, _UnaryOperation) [with _IIter = char; _OIter = char; _UnaryOperation = int (*)(int) noexcept]':
a.cc:12:12:   required from here
   12 |   transform(S.at(0), T.at(0),U.at(0) ,::toupper);
      |   ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:4220:9: error: invalid type argument of unary '*' (have 'char')
 4220 |         *__result = __unary_op(*__first);
      |         ^~~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:4220:32: error: invalid type argument of unary '*' (have 'char')
 4220 |         *__result = __unary_op(*__first);
      |                                ^~~~~~~~
Language: C++

#include <bits/stdc++.h>
#include <string>
#include <algorithm>
#include <cctype>
#include <cstdio>
using namespace std;

int main() {

  string S; string T; string U;
  cin>>S>>T>>U;
  transform(S.at(0), T.at(0),U.at(0) ,::ToUpper);
  cout<<S.at(0)<<T.at(0)<<U.at(0)<<endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:12:41: error: '::ToUpper' has not been declared; did you mean 'toupper'?
   12 |   transform(S.at(0), T.at(0),U.at(0) ,::ToUpper);
      |                                         ^~~~~~~
      |                                         toupper
Language: C++

#include <bits/stdc++.h>
#include <string>
#include <algorithm>
#include <cctype>
#include <cstdio>
using namespace std;
template <typename T_char>
T_char ToUpper (T_char cX) { return toupper(cX); 
int main() {

  string S; string T; string U;
  cin>>S>>T>>U;
  transform(S.at(0), T.at(0),U.at(0),ToUpper<char>);
  cout<<S.at(0)<<T.at(0)<<U.at(0)<<endl;
}

Compiler output:
a.cc: In function 'T_char ToUpper(T_char)':
a.cc:9:9: warning: empty parentheses were disambiguated as a function declaration [-Wvexing-parse]
    9 | int main() {
      |         ^~
a.cc:9:9: note: remove parentheses to default-initialize a variable
    9 | int main() {
      |         ^~
      |         --
a.cc:9:9: note: or replace parentheses with braces to value-initialize a variable
a.cc:9:12: error: a function-definition is not allowed here before '{' token
    9 | int main() {
      |            ^
a.cc:15:2: error: expected '}' at end of input
   15 | }
      |  ^
a.cc:8:28: note: to match this '{'
    8 | T_char ToUpper (T_char cX) { return toupper(cX);
      |                            ^
Language: C++

#include <bits/stdc++.h>
#include <string>
#include <algorithm>
#include <cctype>
#include <cstdio>
using namespace std;
template <typename T_char>
T_char ToUpper (T_char cX) { return toupper(cX); 
int main() {

  string S; string T; string U;
  cin>>S>>T>>U;
  transform(S.at(0), T.at(0),U.at(0),ToUpper);
  cout<<S.at(0)<<T.at(0)<<U.at(0)<<endl;
}

Compiler output:
a.cc: In function 'T_char ToUpper(T_char)':
a.cc:9:9: warning: empty parentheses were disambiguated as a function declaration [-Wvexing-parse]
    9 | int main() {
      |         ^~
a.cc:9:9: note: remove parentheses to default-initialize a variable
    9 | int main() {
      |         ^~
      |         --
a.cc:9:9: note: or replace parentheses with braces to value-initialize a variable
a.cc:9:12: error: a function-definition is not allowed here before '{' token
    9 | int main() {
      |            ^
a.cc:15:2: error: expected '}' at end of input
   15 | }
      |  ^
a.cc:8:28: note: to match this '{'
    8 | T_char ToUpper (T_char cX) { return toupper(cX);
      |                            ^
Language: C++

#include <bits/stdc++.h>
#include <string>
#include <algorithm>
#include <cctype>
#include <cstdio>
using namespace std;
char ToUpper (char cX) { return toupper(cX); } 
int main() {

  string S; string T; string U;
  cin>>S>>T>>U;
  transform(S.at(0), T.at(0),U.at(0),ToUpper);
  cout<<S.at(0)<<T.at(0)<<U.at(0)<<endl;
}

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:1:
/usr/include/c++/14/bits/stl_algo.h: In instantiation of '_OIter std::transform(_IIter, _IIter, _OIter, _UnaryOperation) [with _IIter = char; _OIter = char; _UnaryOperation = char (*)(char)]':
a.cc:12:12:   required from here
   12 |   transform(S.at(0), T.at(0),U.at(0),ToUpper);
      |   ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:4220:9: error: invalid type argument of unary '*' (have 'char')
 4220 |         *__result = __unary_op(*__first);
      |         ^~~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:4220:32: error: invalid type argument of unary '*' (have 'char')
 4220 |         *__result = __unary_op(*__first);
      |                                ^~~~~~~~
Language: C++

#include <bits/stdc++.h>
#include <string>
#include <algorithm>
#include <cctype>
#include <cstdio>
using namespace std;

int main() {
  char ToUpper (char cX) { return toupper(cX); } 
  string S; string T; string U;
  cin>>S>>T>>U;
  transform(S.at(0), T.at(0),U.at(0),ToUpper);
  cout<<S.at(0)<<T.at(0)<<U.at(0)<<endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:9:26: error: a function-definition is not allowed here before '{' token
    9 |   char ToUpper (char cX) { return toupper(cX); }
      |                          ^
a.cc:12:38: error: 'ToUpper' was not declared in this scope; did you mean 'toupper'?
   12 |   transform(S.at(0), T.at(0),U.at(0),ToUpper);
      |                                      ^~~~~~~
      |                                      toupper
Language: C++

#include <bits/stdc++.h>
#include <string>
#include <algorithm>
#include <cctype>
#include <cstdio>
using namespace std;

int main() {
  string S; string T; string U;
  cin>>S>>T>>U;
  transform(S.at(0), T.at(0),U.at(0),ToUpper);
  cout<<S.at(0)<<T.at(0)<<U.at(0)<<endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:11:38: error: 'ToUpper' was not declared in this scope; did you mean 'toupper'?
   11 |   transform(S.at(0), T.at(0),U.at(0),ToUpper);
      |                                      ^~~~~~~
      |                                      toupper
Language: C++

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
#define rep(i, n) for (ll i = 0; i < n; i++)
#define FOR(i, a, b) for (ll i = a; i < b; i++)
#define len(v) ll(v.size())
#define fi first
#define se second

template <class T>
void cout_vec(const vector<T> &vec){
  for(auto itr:vec) cout<<itr<<' ';
  cout<<endl;
}

typedef pair<ll,ll> P;
const ll mod=1e9+7;
const ll inf=1e15;

int main(){
  cin.tie(0);
  ios::sync_with_stdio(false);
  char a,b,c;
  cin>>a>>b>>c;
  string ans=toupper(a)+toupper(b)+toupper(c);
  cout<<ans<<endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:26:35: error: conversion from 'int' to non-scalar type 'std::string' {aka 'std::__cxx11::basic_string<char>'} requested
   26 |   string ans=toupper(a)+toupper(b)+toupper(c);
      |              ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~
Language: C++

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

int main() {
  string s1, s2, s3;
  cin >> s1 >> s2 >> s3;
  
  string s;
  s.push_back(s1.at(0));
  s.push_back(s2.at(0));
  s.push_back(s3.at(0));
  
  transform(s.begin(), s.end(), s.begin(), toupper); 
  cout << s << endl;
  
  return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:13:12: error: no matching function for call to 'transform(std::__cxx11::basic_string<char>::iterator, std::__cxx11::basic_string<char>::iterator, std::__cxx11::basic_string<char>::iterator, <unresolved overloaded function type>)'
   13 |   transform(s.begin(), s.end(), s.begin(), toupper);
      |   ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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:1:
/usr/include/c++/14/bits/stl_algo.h:4209:5: note: candidate: 'template<class _IIter, class _OIter, class _UnaryOperation> _OIter std::transform(_IIter, _IIter, _OIter, _UnaryOperation)'
 4209 |     transform(_InputIterator __first, _InputIterator __last,
      |     ^~~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:4209:5: note:   template argument deduction/substitution failed:
a.cc:13:12: note:   couldn't deduce template parameter '_UnaryOperation'
   13 |   transform(s.begin(), s.end(), s.begin(), toupper);
      |   ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:4247:5: note: candidate: 'template<class _IIter1, class _IIter2, class _OIter, class _BinaryOperation> _OIter std::transform(_IIter1, _IIter1, _IIter2, _OIter, _BinaryOperation)'
 4247 |     transform(_InputIterator1 __first1, _InputIterator1 __last1,
      |     ^~~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:4247:5: note:   candidate expects 5 arguments, 4 provided
In file included from /usr/include/c++/14/algorithm:86:
/usr/include/c++/14/pstl/glue_algorithm_defs.h:156:1: note: candidate: 'template<class _ExecutionPolicy, class _ForwardIterator1, class _ForwardIterator2, class _UnaryOperation> __pstl::__internal::__enable_if_execution_policy<_ExecutionPolicy, _ForwardIterator2> std::transform(_ExecutionPolicy&&, _ForwardIterator1, _ForwardIterator1, _ForwardIterator2, _UnaryOperation)'
  156 | transform(_ExecutionPolicy&& __exec, _ForwardIterator1 __first, _ForwardIterator1 __last, _ForwardIterator2 __result,
      | ^~~~~~~~~
/usr/include/c++/14/pstl/glue_algorithm_defs.h:156:1: note:   candidate expects 5 arguments, 4 provided
/usr/include/c++/14/pstl/glue_algorithm_defs.h:162:1: note: candidate: 'template<class _ExecutionPolicy, class _ForwardIterator1, class _ForwardIterator2, class _ForwardIterator, class _BinaryOperation> __pstl::__internal::__enable_if_execution_policy<_ExecutionPolicy, _ForwardIterator2> std::transform(_ExecutionPolicy&&, _ForwardIterator1, _ForwardIterator1, _ForwardIterator2, _ForwardIterator, _BinaryOperation)'
  162 | transform(_ExecutionPolicy&& __exec, _ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2,
      | ^~~~~~~~~
/usr/include/c++/14/pstl/glue_algorithm_defs.h:162:1: note:   candidate expects 6 arguments, 4 provided
Language: C++

#include<bits/stdc++.h>
using namespace std;
#define rep(i, n) for(int i = 0; i < (n); ++i)
typedef long long ll;
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1;} return 0;}
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1;} return 0;}
const ll INF = 1LL << 60;

int main(){
	string s1, s2, s3;
	cin >> s1 >> s2 >> s3;
	string ans = toupper(s1[0]) + toupper(s2[0]) + toupper(s3[0]);
	puts(ans);
}


Compiler output:
a.cc: In function 'int main()':
a.cc:12:54: error: conversion from 'int' to non-scalar type 'std::string' {aka 'std::__cxx11::basic_string<char>'} requested
   12 |         string ans = toupper(s1[0]) + toupper(s2[0]) + toupper(s3[0]);
      |                      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~
a.cc:13:14: error: cannot convert 'std::string' {aka 'std::__cxx11::basic_string<char>'} to 'const char*'
   13 |         puts(ans);
      |              ^~~
      |              |
      |              std::string {aka std::__cxx11::basic_string<char>}
In file included from /usr/include/c++/14/cstdio:42,
                 from /usr/include/c++/14/ext/string_conversions.h:45,
                 from /usr/include/c++/14/bits/basic_string.h:4154,
                 from /usr/include/c++/14/string:54,
                 from /usr/include/c++/14/bitset:52,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:52,
                 from a.cc:1:
/usr/include/stdio.h:714:30: note:   initializing argument 1 of 'int puts(const char*)'
  714 | extern int puts (const char *__s);
      |                  ~~~~~~~~~~~~^~~
Language: C++

#include <iostream>
#include <vector>

using namespace std;

string compare(string a, string b){
  
  if(a == b)return "EQUAL";
  else if(a.szie() > b.size()) return "GREATER";
  else if(a.size() < b.size()) return "LESS";
  }else{
    int t = a.size();
    t--;
      if(a[t] == b[t]){
        int n = t;
        while(a[n] == b[n] && n >= 0)n--;
        if(a[n]-'0' < b[n]-'0') return "LESS";
        else return "GREATER";
      }else{
        if(a[t]-'0' < b[t]-'0') return "LESS";
        else return "GREATER";
      }
    }
}

int main(){
  string a, b;
  cin >> a >> b;
  string ans;
  ans = compare(a, b);
  cout << ans;
}


Compiler output:
a.cc: In function 'std::string compare(std::string, std::string)':
a.cc:9:13: error: 'std::string' {aka 'class std::__cxx11::basic_string<char>'} has no member named 'szie'; did you mean 'size'?
    9 |   else if(a.szie() > b.size()) return "GREATER";
      |             ^~~~
      |             size
a.cc: At global scope:
a.cc:11:4: error: expected unqualified-id before 'else'
   11 |   }else{
      |    ^~~~
a.cc:24:1: error: expected declaration before '}' token
   24 | }
      | ^
a.cc: In function 'std::string compare(std::string, std::string)':
a.cc:11:3: warning: control reaches end of non-void function [-Wreturn-type]
   11 |   }else{
      |   ^
Language: C++

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


int main(){
    for(int i=0; i<3; i++){
        string s; cin >> s;
        transform(s.begin(), s.end(), s.begin(), toupper);
        cout << s[0];
    }
}


Compiler output:
a.cc: In function 'int main()':
a.cc:8:18: error: no matching function for call to 'transform(std::__cxx11::basic_string<char>::iterator, std::__cxx11::basic_string<char>::iterator, std::__cxx11::basic_string<char>::iterator, <unresolved overloaded function type>)'
    8 |         transform(s.begin(), s.end(), s.begin(), toupper);
      |         ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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:1:
/usr/include/c++/14/bits/stl_algo.h:4209:5: note: candidate: 'template<class _IIter, class _OIter, class _UnaryOperation> _OIter std::transform(_IIter, _IIter, _OIter, _UnaryOperation)'
 4209 |     transform(_InputIterator __first, _InputIterator __last,
      |     ^~~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:4209:5: note:   template argument deduction/substitution failed:
a.cc:8:18: note:   couldn't deduce template parameter '_UnaryOperation'
    8 |         transform(s.begin(), s.end(), s.begin(), toupper);
      |         ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:4247:5: note: candidate: 'template<class _IIter1, class _IIter2, class _OIter, class _BinaryOperation> _OIter std::transform(_IIter1, _IIter1, _IIter2, _OIter, _BinaryOperation)'
 4247 |     transform(_InputIterator1 __first1, _InputIterator1 __last1,
      |     ^~~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:4247:5: note:   candidate expects 5 arguments, 4 provided
In file included from /usr/include/c++/14/algorithm:86:
/usr/include/c++/14/pstl/glue_algorithm_defs.h:156:1: note: candidate: 'template<class _ExecutionPolicy, class _ForwardIterator1, class _ForwardIterator2, class _UnaryOperation> __pstl::__internal::__enable_if_execution_policy<_ExecutionPolicy, _ForwardIterator2> std::transform(_ExecutionPolicy&&, _ForwardIterator1, _ForwardIterator1, _ForwardIterator2, _UnaryOperation)'
  156 | transform(_ExecutionPolicy&& __exec, _ForwardIterator1 __first, _ForwardIterator1 __last, _ForwardIterator2 __result,
      | ^~~~~~~~~
/usr/include/c++/14/pstl/glue_algorithm_defs.h:156:1: note:   candidate expects 5 arguments, 4 provided
/usr/include/c++/14/pstl/glue_algorithm_defs.h:162:1: note: candidate: 'template<class _ExecutionPolicy, class _ForwardIterator1, class _ForwardIterator2, class _ForwardIterator, class _BinaryOperation> __pstl::__internal::__enable_if_execution_policy<_ExecutionPolicy, _ForwardIterator2> std::transform(_ExecutionPolicy&&, _ForwardIterator1, _ForwardIterator1, _ForwardIterator2, _ForwardIterator, _BinaryOperation)'
  162 | transform(_ExecutionPolicy&& __exec, _ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2,
      | ^~~~~~~~~
/usr/include/c++/14/pstl/glue_algorithm_defs.h:162:1: note:   candidate expects 6 arguments, 4 provided
Language: C++

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


int main(){
    for(int i=0; i<n; i++){
        string s; cin >> s;
        transform(s.begin(), s.end(), s.begin(), ::toupper);
        cout << s[0];
    }
}


Compiler output:
a.cc: In function 'int main()':
a.cc:6:20: error: 'n' was not declared in this scope
    6 |     for(int i=0; i<n; i++){
      |                    ^
Language: C++

int main() {
	string a, b, c;
	cin >> a >> b >> c;

	int d = 'A' - 'a';


	cout << (char)(a[0]+d) << (char)(b[0]+d) << (char)(c[0]+d) << endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:2:9: error: 'string' was not declared in this scope
    2 |         string a, b, c;
      |         ^~~~~~
a.cc:3:9: error: 'cin' was not declared in this scope
    3 |         cin >> a >> b >> c;
      |         ^~~
a.cc:3:16: error: 'a' was not declared in this scope
    3 |         cin >> a >> b >> c;
      |                ^
a.cc:3:21: error: 'b' was not declared in this scope
    3 |         cin >> a >> b >> c;
      |                     ^
a.cc:3:26: error: 'c' was not declared in this scope
    3 |         cin >> a >> b >> c;
      |                          ^
a.cc:8:9: error: 'cout' was not declared in this scope
    8 |         cout << (char)(a[0]+d) << (char)(b[0]+d) << (char)(c[0]+d) << endl;
      |         ^~~~
a.cc:8:71: error: 'endl' was not declared in this scope
    8 |         cout << (char)(a[0]+d) << (char)(b[0]+d) << (char)(c[0]+d) << endl;
      |                                                                       ^~~~
Language: C++

#include <bits/stdc++.h>
using namespace std;
 
int main(){
    string a, b, c;
    cin >> a >> b >> c;
    
    char A = a[0];
    char B = b[0];
    char C = c[0];

    cout << toupr(A) << toupr(B) << toupr(C) << endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:12:13: error: 'toupr' was not declared in this scope; did you mean 'toupper'?
   12 |     cout << toupr(A) << toupr(B) << toupr(C) << endl;
      |             ^~~~~
      |             toupper
Language: C++

#include <bits/stdc++.h>
#define REP(i, n) for(ll i = 0; i < (ll)n; i++)
#define FOR(i, a, b) for(ll i = (a); i < (ll)b; i++)
#define ALL(obj) (obj).begin(), (obj).end()
#define INF (1ll << 60)
#define sz(x) int(x.size())
using namespace std;
typedef long long ll;
typedef double db;
typedef string str;
typedef pair<ll, ll> p;
constexpr int MOD = 1000000007;
using ll = long long;
template <class T> inline bool chmin(T &a, T b) {
    if(a > b) {
        a = b;
        return true;
    }
    return false;
}
template <class T> inline bool chmax(T &a, T b) {
    if(a < b) {
        a = b;
        return true;
    }
    return false;
}

void print(const std::vector<int> &v) {
    std::for_each(v.begin(), v.end(), [](int x) { std::cout << x << " "; });
    std::cout << std::endl;
}

int main() {
    REP(i, 3) {
        string s;
        cin >> s;
        ans += toupper(s[0]);
    }
    cout << ans << endl;
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:38:9: error: 'ans' was not declared in this scope; did you mean 'abs'?
   38 |         ans += toupper(s[0]);
      |         ^~~
      |         abs
a.cc:40:13: error: 'ans' was not declared in this scope; did you mean 'abs'?
   40 |     cout << ans << endl;
      |             ^~~
      |             abs
Language: C++

#include <bits/stdc++.h>
#define REP(i, n) for(ll i = 0; i < (ll)n; i++)
#define FOR(i, a, b) for(ll i = (a); i < (ll)b; i++)
#define ALL(obj) (obj).begin(), (obj).end()
#define INF (1ll << 60)
#define sz(x) int(x.size())
using namespace std;
typedef long long ll;
typedef double db;
typedef string str;
typedef pair<ll, ll> p;
constexpr int MOD = 1000000007;
using ll = long long;
template <class T> inline bool chmin(T &a, T b) {
    if(a > b) {
        a = b;
        return true;
    }
    return false;
}
template <class T> inline bool chmax(T &a, T b) {
    if(a < b) {
        a = b;
        return true;
    }
    return false;
}

void print(const std::vector<int> &v) {
    std::for_each(v.begin(), v.end(), [](int x) { std::cout << x << " "; });
    std::cout << std::endl;
}

int main() {
    string s1, s2, s3;
    cin >> s1 >> s2 >> s3;
    string ans = s1[0] + s2[0] + s3[0];
    cout << toupper(ans) << endl;
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:37:32: error: conversion from 'int' to non-scalar type 'std::string' {aka 'std::__cxx11::basic_string<char>'} requested
   37 |     string ans = s1[0] + s2[0] + s3[0];
a.cc:38:20: error: no matching function for call to 'toupper(std::string&)'
   38 |     cout << toupper(ans) << endl;
      |             ~~~~~~~^~~~~
In file included from /usr/include/c++/14/bits/basic_ios.h:37,
                 from /usr/include/c++/14/ios:46,
                 from /usr/include/c++/14/istream:40,
                 from /usr/include/c++/14/sstream:40,
                 from /usr/include/c++/14/complex:45,
                 from /usr/include/c++/14/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:127,
                 from a.cc:1:
/usr/include/c++/14/bits/locale_facets.h:2687:5: note: candidate: 'template<class _CharT> _CharT std::toupper(_CharT, const locale&)'
 2687 |     toupper(_CharT __c, const locale& __loc)
      |     ^~~~~~~
/usr/include/c++/14/bits/locale_facets.h:2687:5: note:   candidate expects 2 arguments, 1 provided
In file included from /usr/include/c++/14/cctype:42,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:35:
/usr/include/ctype.h:125:12: note: candidate: 'int toupper(int)'
  125 | extern int toupper (int __c) __THROW;
      |            ^~~~~~~
/usr/include/ctype.h:125:25: note:   no known conversion for argument 1 from 'std::string' {aka 'std::__cxx11::basic_string<char>'} to 'int'
  125 | extern int toupper (int __c) __THROW;
      |                     ~~~~^~~