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

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

int main(){
  int N,i,result;
  int A = 0;
  int B = 0;
  
  cin >> N;
  vector int a(N);
  vector int b(N);
  
  for(i=0; i<N; i++){
  cin >> a.at(i) >> b.at(i);
  A = A + a.at(i);
  B = B + b.at(i);
  }
  
  result = A - B;
  cout << result << endl;

return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:10:3: error: two or more data types in declaration of 'a'
   10 |   vector int a(N);
      |   ^~~~~~
a.cc:11:3: error: two or more data types in declaration of 'b'
   11 |   vector int b(N);
      |   ^~~~~~
a.cc:14:10: error: 'a' was not declared in this scope
   14 |   cin >> a.at(i) >> b.at(i);
      |          ^
a.cc:14:21: error: 'b' was not declared in this scope
   14 |   cin >> a.at(i) >> b.at(i);
      |                     ^
Language: C++

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

int main(){
  int a,b[120];
    cin>>a;
  for(int i=0;i++)
  cin >>b[i];
  
  sort(b ,b+a,greater<int>());
  int c =0;
  int d =0;
    for(int i=0;i<a;i++){

   if(i%2 ==0){
     c += b[i];
   }
      else{
        d+=b[i]
      }
    }
    cout << c-d << endl;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:7:18: error: expected ';' before ')' token
    7 |   for(int i=0;i++)
      |                  ^
      |                  ;
a.cc:19:16: error: expected ';' before '}' token
   19 |         d+=b[i]
      |                ^
      |                ;
   20 |       }
      |       ~
Language: C++

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

int main() {
  int N;
  cin >> N;
  
  vector<int> A(N);
  for (int i = 0; i < N; i++){
    cin >> A.at(i);
  }
  
  vector<int> sort(N);
  for (int j = 0; j < N; j++){
    int max = 0;
    int max_i = -1;
    for (int i = 0; i < N; i++){
      if (A.at(i) > max){
        max = A.at(i);
        max_i = i;
      }
    }
    sort.at(j) = max;
    A.at(max_i) = 0;
#    cout << sort.at(j) << endl;
  }
  
  int Alice = 0;
  int Bob = 0;
  for (int j = 0; j < N; j++){
    if (j%2==0)
      Alice += sort.at(j);
    else
      Bob += sort.at(j);
  }
  cout << Alice - Bob << endl;
  
}

Compiler output:
a.cc:25:6: error: invalid preprocessing directive #cout
   25 | #    cout << sort.at(j) << endl;
      |      ^~~~
Language: C++

#include <iostream>
#include <cmath>
#include <vector>
using namespace std;
int main(int argc, const char * argv[]) {
    int N;
    cin >> N;
    vector<int> a(N,0);
    for(int n = 0; n < N; ++n){
        cin >> a[n];
    }
    sort(a.begin(), a.end(), greater<int>());
    
    int bob = 0;
    int ann = 0;
    for(int i = 0; i < a.size(); ++i){
        if(i % 2 == 0){
            bob += a[i];
        }
        else{
            ann += a[i];
        }
    }
    int ans = bob - ann;
    cout << ans;
    
    return 0;
}

Compiler output:
a.cc: In function 'int main(int, const char**)':
a.cc:12:5: error: 'sort' was not declared in this scope; did you mean 'sqrt'?
   12 |     sort(a.begin(), a.end(), greater<int>());
      |     ^~~~
      |     sqrt
Language: Java

import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] nums = new int[n];
        for (int i = 0; i < n; i++) {
            nums[i] = sc.nextInt();
        }
        Arrays.sort(nums, Collections.reverseOrder());
        int aliceSum = 0;
        int bobSum = 0;
        for (int i = 0; i < n; i++) {
            if (i % 2 == 0) {
                aliceSum += nums[i];
            } else {
                bobSum += nums[i];
            }
        }
        System.out.println(aliceSum - bobSum);
    }
}

Compiler output:
Main.java:11: error: no suitable method found for sort(int[],Comparator<Object>)
        Arrays.sort(nums, Collections.reverseOrder());
              ^
    method Arrays.<T#1>sort(T#1[],Comparator<? super T#1>) is not applicable
      (inference variable T#1 has incompatible bounds
        equality constraints: int
        upper bounds: Object)
    method Arrays.<T#2>sort(T#2[],int,int,Comparator<? super T#2>) is not applicable
      (cannot infer type-variable(s) T#2
        (actual and formal argument lists differ in length))
  where T#1,T#2 are type-variables:
    T#1 extends Object declared in method <T#1>sort(T#1[],Comparator<? super T#1>)
    T#2 extends Object declared in method <T#2>sort(T#2[],int,int,Comparator<? super T#2>)
Note: Some messages have been simplified; recompile with -Xdiags:verbose to get full output
1 error
Language: Java

import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] nums = new int[n];
        for (int i = 0; i < n; i++) {
            nums[i] = sc.nextInt();
        }
        Arrays.sort(nums);
        Collections.reverse(nums);
        int aliceSum = 0;
        int bobSum = 0;
        for (int i = 0; i < n; i++) {
            if (i % 2 == 0) {
                aliceSum += nums[i];
            } else {
                bobSum += nums[i];
            }
        }
        System.out.println(aliceSum - bobSum);
    }
}

Compiler output:
Main.java:12: error: incompatible types: int[] cannot be converted to List<?>
        Collections.reverse(nums);
                            ^
Note: Some messages have been simplified; recompile with -Xdiags:verbose to get full output
1 error
Language: Java

import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] nums = new int[n];
        for (int i = 0; i < n; i++) {
            nums[i] = sc.nextInt();
        }
        Arrays.sort(nums);
        Collctions.reverse(nums);
        int aliceSum = 0;
        int bobSum = 0;
        for (int i = 0; i < n; i++) {
            if (i % 2 == 0) {
                aliceSum += nums[i];
            } else {
                bobSum += nums[i];
            }
        }
        System.out.println(aliceSum - bobSum);
    }
}

Compiler output:
Main.java:12: error: cannot find symbol
        Collctions.reverse(nums);
        ^
  symbol:   variable Collctions
  location: class Main
1 error
Language: Java

import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] nums = new int[n + 1];
        for (int i = 0; i < n; i++) {
            nums[i] = sc.nextInt();
        }
        Arrays.sort(nums);
        int aliceSum = 0;
        int bobSum = 0;
        boolean isAliceTurn = true;
        for (int i = nums.length - 1; i >= 0; i--) {
            if (isAliceTurn) {
                aliceSum += nums[i];
                isAliceTurn = false;
            } else {
                bobSum += nums[i];
                isAliceTurn = true;
            }
        }
        return aliceSum - bobSum;
    }
}

Compiler output:
Main.java:24: error: incompatible types: unexpected return value
        return aliceSum - bobSum;
                        ^
1 error
Language: C++

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

int main() {
  int N;
  cin >> N;
  vector<int>a(N);
  for(int i=0; i<N i++){
    cin >> a.at(i);
  }
  sort(a.begin(), a.end());
  int Alice=0;
  int Bob=0;
  for(int i=0; i<N; i++){
    if(i%2 == 1){
      Alice += a.at(i);
    }else if(i%2 == 0){
      Bob += a.at(i);
    }
  }
  int ans = Alice = Bob;
  cout << ans << endl;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:8:19: error: expected ';' before 'i'
    8 |   for(int i=0; i<N i++){
      |                   ^~
      |                   ;
Language: C++

n = input()
a = list(map(int, input().split()))
a= sorted(a, reverse=True)
print(a)
ans =0
for i in a:
    if i%2 == 0:
        ans += i
    elif i%2 ==1:
        ans -= i
print(ans)

Compiler output:
a.cc:1:1: error: 'n' does not name a type
    1 | n = input()
      | ^
Language: C++

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

int main() {
  int N;
  cin >> N;
  vector<int> vec(N);
  
  for( int i = 0; i < N; i++){
    cin >> vec.at(i);
  }
  sort(vec.begin(),vec.end());
  reverse(vec.begin(),vec.end());
  
  int A = 0, B = 0;
  for( int j = 0; j < N; j++){
    if(j%2 = 0){
      A += vec.at(j);
    }
    else{
      B += vec.at(j);
    }
  }
  cout << A-B << endl;
  
      

}


Compiler output:
a.cc: In function 'int main()':
a.cc:17:9: error: lvalue required as left operand of assignment
   17 |     if(j%2 = 0){
      |        ~^~
Language: C++

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

int main() {
  int N;
  cin >> N;
  vector<int> vec(N);
  
  for( int i = 0; i < N; i++){
    cin >> vec.at(i);
  }
  sort(vec.begin(),vec.end());
  reverse(vec.begin(),vec.end());
  
  int A = 0, B = 0;
  for( int j = 0; i < N; i++){
    if(j % 2 = 0){
      A += vec.at(j);
    }
    else{
      B += vec.at(j);
    }
  }
  cout << A-B << endl;
  
      

}


Compiler output:
a.cc: In function 'int main()':
a.cc:16:19: error: 'i' was not declared in this scope
   16 |   for( int j = 0; i < N; i++){
      |                   ^
a.cc:17:10: error: lvalue required as left operand of assignment
   17 |     if(j % 2 = 0){
      |        ~~^~~
Language: C++

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

int main(){
  int N, x, sum;
  cin >> N;
  vector<int> a(N);
  for (int i=0; i<N; i++) {
    cin >> a.at(i);
  }
  sort(a.begin(), a.end());
  reverse(a.begin(), a.end());
  x = 1;
  sum = 0;
  for (int i=0; i<N; i++) {
    sum += a.at(i)*x;
    x *= -1
  }
  cout << sum << endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:17:12: error: expected ';' before '}' token
   17 |     x *= -1
      |            ^
      |            ;
   18 |   }
      |   ~
Language: C++

#include <iostream>
using namespace std;
int main(){
  int N, a, b;
  cin >> N;
  int card[N];
  for (int i = 0; i < N; i++){
    cin >> card[i];
  }
  for ( int i = 0; i < N; i++){
    for (int j = i; j < N-i; j++){
      if(card[i] > card[j]){
        int temp = card[j];
        card[j] = card[i];
        card[i] = temp;
      }
    }
  }
  for(int i = 0; i < N; i++){
    if(i%2=0)
      a+=card[i];
    else
      b+=card[i];
  }
  cout << a-b << endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:20:9: error: lvalue required as left operand of assignment
   20 |     if(i%2=0)
      |        ~^~
Language: C++

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

int main()
{
  int N ;
  cin>>N ;
  vector<int>a(N) ;
  for(int i=0;i<N;i++) cin>>a[i] ;
  
  /*配列を大きい順にソート*/
  sort(a.begin(),a.end()) ;
  reverse(a.begin(),a.end()) ;
  
  int A_hand=0,B_hand=0;
  for(int i=0;i<N;i++){
    if(i%2==0) A_hand+=a.at(i) ;
    else B_hand+=a.at(i) ;
  }
  
  cout<<A_hand-B_hand<<endl ;

  return 0 ;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:13:3: error: 'sort' was not declared in this scope; did you mean 'short'?
   13 |   sort(a.begin(),a.end()) ;
      |   ^~~~
      |   short
a.cc:14:3: error: 'reverse' was not declared in this scope
   14 |   reverse(a.begin(),a.end()) ;
      |   ^~~~~~~
Language: C++

#include<iostream>
#include<vector>
//#include<iterator>
#include<algorithm>
using namespace std ;

int main()
{
  int N ;
  cin>>N ;
  int a[N] ;
  for(int i=0;i<N;i++) cin>>a[i] ;
  
  /*配列を大きい順にソート*/
  sort(a.begin(),a.end()) ;
  reverse(a.begin(),a.end()) ;
  
  int A_hand=0,B_hand=0;
  for(int i=0;i<N;i++){
    if(i%2==0) A_hand+=a.at(i) ;
    else B_hand+=a.at(i) ;
  }
  
  cout<<A_hand-B_hand<<endl ;

  return 0 ;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:15:10: error: request for member 'begin' in 'a', which is of non-class type 'int [N]'
   15 |   sort(a.begin(),a.end()) ;
      |          ^~~~~
a.cc:15:20: error: request for member 'end' in 'a', which is of non-class type 'int [N]'
   15 |   sort(a.begin(),a.end()) ;
      |                    ^~~
a.cc:16:13: error: request for member 'begin' in 'a', which is of non-class type 'int [N]'
   16 |   reverse(a.begin(),a.end()) ;
      |             ^~~~~
a.cc:16:23: error: request for member 'end' in 'a', which is of non-class type 'int [N]'
   16 |   reverse(a.begin(),a.end()) ;
      |                       ^~~
a.cc:20:26: error: request for member 'at' in 'a', which is of non-class type 'int [N]'
   20 |     if(i%2==0) A_hand+=a.at(i) ;
      |                          ^~
a.cc:21:20: error: request for member 'at' in 'a', which is of non-class type 'int [N]'
   21 |     else B_hand+=a.at(i) ;
      |                    ^~
Language: C++

#include<iostream>
#include<vector>
#include<iterator>
using namespace std ;

int main()
{
  int N ;
  cin>>N ;
  int a[N] ;
  for(int i=0;i<N;i++) cin>>a[i] ;
  
  /*配列を大きい順にソート*/
  sort(a.begin(),a.end()) ;
  reverse(a.begin(),a.end()) ;
  
  int A_hand=0,B_hand=0;
  for(int i=0;i<N;i++){
    if(i%2==0) A_hand+=a.at(i) ;
    else B_hand+=a.at(i) ;
  }
  
  cout<<A_hand-B_hand<<endl ;

  return 0 ;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:14:10: error: request for member 'begin' in 'a', which is of non-class type 'int [N]'
   14 |   sort(a.begin(),a.end()) ;
      |          ^~~~~
a.cc:14:20: error: request for member 'end' in 'a', which is of non-class type 'int [N]'
   14 |   sort(a.begin(),a.end()) ;
      |                    ^~~
a.cc:14:3: error: 'sort' was not declared in this scope; did you mean 'short'?
   14 |   sort(a.begin(),a.end()) ;
      |   ^~~~
      |   short
a.cc:15:13: error: request for member 'begin' in 'a', which is of non-class type 'int [N]'
   15 |   reverse(a.begin(),a.end()) ;
      |             ^~~~~
a.cc:15:23: error: request for member 'end' in 'a', which is of non-class type 'int [N]'
   15 |   reverse(a.begin(),a.end()) ;
      |                       ^~~
a.cc:15:3: error: 'reverse' was not declared in this scope
   15 |   reverse(a.begin(),a.end()) ;
      |   ^~~~~~~
a.cc:19:26: error: request for member 'at' in 'a', which is of non-class type 'int [N]'
   19 |     if(i%2==0) A_hand+=a.at(i) ;
      |                          ^~
a.cc:20:20: error: request for member 'at' in 'a', which is of non-class type 'int [N]'
   20 |     else B_hand+=a.at(i) ;
      |                    ^~
Language: C++

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

int main()
{
  int N ;
  cin>>N ;
  int a[N] ;
  for(int i=0;i<N;i++) cin>>a[i] ;
  
  /*配列を大きい順にソート*/
  sort(a.begin(),a.end()) ;
  reverse(a.begin(),a.end()) ;
  
  int A_hand=0,B_hand=0;
  for(int i=0;i<N;i++){
    if(i%2==0) A_hand+=a.at(i) ;
    else B_hand+=a.at(i) ;
  }
  
  cout<<A_hand-B_hand<<endl ;

  return 0 ;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:13:10: error: request for member 'begin' in 'a', which is of non-class type 'int [N]'
   13 |   sort(a.begin(),a.end()) ;
      |          ^~~~~
a.cc:13:20: error: request for member 'end' in 'a', which is of non-class type 'int [N]'
   13 |   sort(a.begin(),a.end()) ;
      |                    ^~~
a.cc:13:3: error: 'sort' was not declared in this scope; did you mean 'short'?
   13 |   sort(a.begin(),a.end()) ;
      |   ^~~~
      |   short
a.cc:14:13: error: request for member 'begin' in 'a', which is of non-class type 'int [N]'
   14 |   reverse(a.begin(),a.end()) ;
      |             ^~~~~
a.cc:14:23: error: request for member 'end' in 'a', which is of non-class type 'int [N]'
   14 |   reverse(a.begin(),a.end()) ;
      |                       ^~~
a.cc:14:3: error: 'reverse' was not declared in this scope
   14 |   reverse(a.begin(),a.end()) ;
      |   ^~~~~~~
a.cc:18:26: error: request for member 'at' in 'a', which is of non-class type 'int [N]'
   18 |     if(i%2==0) A_hand+=a.at(i) ;
      |                          ^~
a.cc:19:20: error: request for member 'at' in 'a', which is of non-class type 'int [N]'
   19 |     else B_hand+=a.at(i) ;
      |                    ^~
Language: C++

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

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


Compiler output:
a.cc: In function 'int main()':
a.cc:11:10: error: no matching function for call to 'reverse(std::vector<int>::iterator, <unresolved overloaded function type>)'
   11 |   reverse(a.begin(), a.end);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~
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:1083:5: note: candidate: 'void std::reverse(_BIter, _BIter) [with _BIter = __gnu_cxx::__normal_iterator<int*, vector<int> >]'
 1083 |     reverse(_BidirectionalIterator __first, _BidirectionalIterator __last)
      |     ^~~~~~~
/usr/include/c++/14/bits/stl_algo.h:1083:68: note:   no known conversion for argument 2 from '<unresolved overloaded function type>' to '__gnu_cxx::__normal_iterator<int*, std::vector<int> >'
 1083 |     reverse(_BidirectionalIterator __first, _BidirectionalIterator __last)
      |                                             ~~~~~~~~~~~~~~~~~~~~~~~^~~~~~
In file included from /usr/include/c++/14/algorithm:86:
/usr/include/c++/14/pstl/glue_algorithm_defs.h:249:1: note: candidate: 'template<class _ExecutionPolicy, class _BidirectionalIterator> __pstl::__internal::__enable_if_execution_policy<_ExecutionPolicy, void> std::reverse(_ExecutionPolicy&&, _BidirectionalIterator, _BidirectionalIterator)'
  249 | reverse(_ExecutionPolicy&& __exec, _BidirectionalIterator __first, _BidirectionalIterator __last);
      | ^~~~~~~
/usr/include/c++/14/pstl/glue_algorithm_defs.h:249:1: note:   candidate expects 3 arguments, 2 provided
Language: C++

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

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


Compiler output:
a.cc: In function 'int main()':
a.cc:11:10: error: no matching function for call to 'reverse(std::vector<int>::iterator, <unresolved overloaded function type>)'
   11 |   reverse(a.begin(), a.end);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~
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:1083:5: note: candidate: 'void std::reverse(_BIter, _BIter) [with _BIter = __gnu_cxx::__normal_iterator<int*, vector<int> >]'
 1083 |     reverse(_BidirectionalIterator __first, _BidirectionalIterator __last)
      |     ^~~~~~~
/usr/include/c++/14/bits/stl_algo.h:1083:68: note:   no known conversion for argument 2 from '<unresolved overloaded function type>' to '__gnu_cxx::__normal_iterator<int*, std::vector<int> >'
 1083 |     reverse(_BidirectionalIterator __first, _BidirectionalIterator __last)
      |                                             ~~~~~~~~~~~~~~~~~~~~~~~^~~~~~
In file included from /usr/include/c++/14/algorithm:86:
/usr/include/c++/14/pstl/glue_algorithm_defs.h:249:1: note: candidate: 'template<class _ExecutionPolicy, class _BidirectionalIterator> __pstl::__internal::__enable_if_execution_policy<_ExecutionPolicy, void> std::reverse(_ExecutionPolicy&&, _BidirectionalIterator, _BidirectionalIterator)'
  249 | reverse(_ExecutionPolicy&& __exec, _BidirectionalIterator __first, _BidirectionalIterator __last);
      | ^~~~~~~
/usr/include/c++/14/pstl/glue_algorithm_defs.h:249:1: note:   candidate expects 3 arguments, 2 provided
a.cc:14:17: error: expected ';' before 'for'
   14 |     A += a.at(i)
      |                 ^
      |                 ;
   15 |   for(int i = 1; i < N; i += 2)
      |   ~~~            
a.cc:15:18: error: 'i' was not declared in this scope
   15 |   for(int i = 1; i < N; i += 2)
      |                  ^
Language: C++

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

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

    
   
  
 
    
    
    
   
 
  
  


Compiler output:
a.cc: In function 'int main()':
a.cc:22:10: error: unable to find numeric literal operator 'operator""n'
   22 |       if(2n - 1 % 2 == 1 ) {
      |          ^~
a.cc:31:11: error: 'A' was not declared in this scope
   31 |   cout << A - B << endl;
      |           ^
a.cc:31:15: error: 'B' was not declared in this scope
   31 |   cout << A - B << endl;
      |               ^
Language: C++

#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
int main() {
  int n;
  cin>>n;
  vector<int> a(n);
  rep(i,n){
    cin>>a.at(i);
  }
  sort(a.begin(), a.end(), greater<int>());
    int ans = 0;
    rep(j,n){
        ans = ans + pow(-1, j) * a[j];
    }
    cou<<ans<<endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:16:5: error: 'cou' was not declared in this scope; did you mean 'cos'?
   16 |     cou<<ans<<endl;
      |     ^~~
      |     cos
Language: C++

#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
int main() {
  int n;
  cin>>n;
  vector<int> a(n);
  rep(i,n){
    cin>>a.at(i);
  }
  sort(a.begin(), a.end(), greater<int>());
    int ans = 0;
    rep(j,n){
        ans = ans + pow(-1, i) * a[j];
    }
    cou<<ans<<endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:14:29: error: 'i' was not declared in this scope
   14 |         ans = ans + pow(-1, i) * a[j];
      |                             ^
a.cc:16:5: error: 'cou' was not declared in this scope; did you mean 'cos'?
   16 |     cou<<ans<<endl;
      |     ^~~
      |     cos
Language: C++

#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(ll i=0; i<n; i++)
typedef long long ll;
typedef long long unsigned int llu;
ll mod = 1000000007;
ll INF = 1000000009;

void solve(){
    int n;
    cin >> n;
    int a[n+10];
    rep(i,n){
        cin >> a[i];
    }
    a[n]=0;
    sort(a.begin(), a.end()+1);
    int suma = 0;
    int sumb = 0;
    for(int i=0; i<n; i=i+2){
        suma += a[i];
        sumb += a[i+1];
    }
    cout << suma-sumb << endl;
}

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


Compiler output:
a.cc: In function 'void solve()':
a.cc:17:12: error: request for member 'begin' in 'a', which is of non-class type 'int [(n + 10)]'
   17 |     sort(a.begin(), a.end()+1);
      |            ^~~~~
a.cc:17:23: error: request for member 'end' in 'a', which is of non-class type 'int [(n + 10)]'
   17 |     sort(a.begin(), a.end()+1);
      |                       ^~~
Language: C++

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

int main() {
    int N;
    int a[110];
    cin >> N;
    for (int i = 0; 1 < N; ++i) cin >> a[i];
  
    sort(a, a + N, greater<int>());
    int Alice = 0;
    int Bob = 0;
    for (int i = 0; i < N; ++i) {
        if (i % 2 == 0) {
            Alice += a[i];
        }else{
            Bob += a[i];
        }
    }
    cout << Alice - Bob << endl;a
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:21:34: error: expected ';' before 'return'
   21 |     cout << Alice - Bob << endl;a
      |                                  ^
      |                                  ;
   22 |     return 0;
      |     ~~~~~~
Language: C++

#include <bits/stdc++.h>
using namespace std;
int main(){
  int n,a=0,b=0;
  cin>>n;
  vector<int> v(n);
  for(int i=0;i<n;i++) cin>>v[i];
  sort(v.begin(),v.end());
  if(v.size()%2==0){
    for(int i=0;i<s.size()/2;i++){
      a+=v[2*i-1];
      b+=v[2*i];
    }
  }else{
    for(int i=0;i<s.size()/2;i++){
      a+=v[2*i];
    }
    for(int i=0;i<(s.size()+1)/2;i++){
      b+=v[2*i-1];
    }
  }
  cout<<abs(a-b)<<endl;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:10:19: error: 's' was not declared in this scope
   10 |     for(int i=0;i<s.size()/2;i++){
      |                   ^
a.cc:15:19: error: 's' was not declared in this scope
   15 |     for(int i=0;i<s.size()/2;i++){
      |                   ^
a.cc:18:20: error: 's' was not declared in this scope
   18 |     for(int i=0;i<(s.size()+1)/2;i++){
      |                    ^
Language: C++

#include<iostream>
using namespace std;
int main(void){
  
  int n, alice = 0, bob = 0;
  
  cin >> n;
  
  int a[n];
  
  for(int i = 0; i < n; i++){
    cin >> a[i];
  }
  
  sort(a, a+n, greater<int>());
  
  for(int i = 0; i < n; i=i+2){
    alice += a[i];
  }
  for(int i = 1; i < n; i=i+2){
    bob += a[i];
  }
  
  cout << alice-bob << endl;
  
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:15:3: error: 'sort' was not declared in this scope; did you mean 'short'?
   15 |   sort(a, a+n, greater<int>());
      |   ^~~~
      |   short
Language: C++

#include<iostream>
using namespace std;
int main(void){
  
  int n, alice, bob;
  
  cin >> n;
  
  int a[n];
  
  for(int i = 0; i < n; i++){
    cin >> a[i];
  }
  
  sort(a, a+n, greater<int>());
  
  for(int i = 0; i < n; i=i+2){
    alice += a[i];
  }
  for(int i = 1; i < n; i=i+2){
    bob += a[i];
  }
  
  if(alice > bob){
    cout << alice-bob << endl;
  }else{
    cout << bob-alice << endl;
  }
  
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:15:3: error: 'sort' was not declared in this scope; did you mean 'short'?
   15 |   sort(a, a+n, greater<int>());
      |   ^~~~
      |   short
Language: C++

#include<iostream>
using namespace std;
int main(void){
  
  int n, alice, bob;
  
  cin >> n;
  
  int a[n];
  
  for(int i = 0; i < n; i++){
    cin >> a[i];
  }
  
  sort(a, a+N, greater<int>());
  
  for(int i = 0; i < n; i=i+2){
    alice += a[i];
  }
  for(int i = 1; i < n; i=i+2){
    bob += a[i];
  }
  
  if(alice > bob){
    cout << alice-bob << endl;
  }else{
    cout << bob-alice << endl;
  }
  
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:15:13: error: 'N' was not declared in this scope
   15 |   sort(a, a+N, greater<int>());
      |             ^
a.cc:15:3: error: 'sort' was not declared in this scope; did you mean 'short'?
   15 |   sort(a, a+N, greater<int>());
      |   ^~~~
      |   short
Language: C++

#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define rep2(i, s, n) for (int i = (s); i < (int)(n); i++)
typedef long long ll;

int main() {
    int N;
    vector<int> cards;
    for (int i = 0; i < N; i++){
        int a;
        cin >> a;
        cards.push_back(a)
    }
    sort(cards.begin(), cards.end())
    int cntAlice = 0;
    int cntBob = 0;
    int i = N - 1;
    while (i >= 0) {
        cntAlice += cards[i];
        i--;
        if (i >= 0){
            cntBob += cards[i];
            i--;
        }
    }
    cout << cntAlice - cntBob << endl;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:13:27: error: expected ';' before '}' token
   13 |         cards.push_back(a)
      |                           ^
      |                           ;
   14 |     }
      |     ~                      
a.cc:15:37: error: expected ';' before 'int'
   15 |     sort(cards.begin(), cards.end())
      |                                     ^
      |                                     ;
   16 |     int cntAlice = 0;
      |     ~~~                              
a.cc:20:9: error: 'cntAlice' was not declared in this scope
   20 |         cntAlice += cards[i];
      |         ^~~~~~~~
a.cc:27:13: error: 'cntAlice' was not declared in this scope
   27 |     cout << cntAlice - cntBob << endl;
      |             ^~~~~~~~
Language: C++

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

int main(){
  int N;
  cin>>N;
  vector<int> vec(N);
  if(int i=0;i<N;i++){
    cin>>vec.at(i);
  }
  
  sort(vec.begin(),vec.end());
  reverse(vec.begin(),vec.end());
  
  int A=0,B=0;
  for(int i=0;i<N;i++){
    if(i%2==0){
      A+=vec.at(i);
    }else{
      B+=vec.at(i);
    }
  }
  
  cout<<A-B<<endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:8:17: error: expected ')' before ';' token
    8 |   if(int i=0;i<N;i++){
      |     ~           ^
      |                 )
a.cc:8:18: error: 'i' was not declared in this scope
    8 |   if(int i=0;i<N;i++){
      |                  ^
Language: C++

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

int main() {
  int N;
  cin >> N;
  vector<int> num(N)
  for (int i = 0; i < N; i++){
    cin >> num.at(i);
  }
  sort(num.begin(),num.end());
  reverse(num.begin(),num.end());
  int A = 0;
  int B = 0;
  for (int i = 0; i < N; i++){
    if(i % 2 == 0)
      A += num.at(i);
    else
      B += num.at(i);
  }
  cout << A - B << endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:8:3: error: expected ',' or ';' before 'for'
    8 |   for (int i = 0; i < N; i++){
      |   ^~~
a.cc:8:19: error: 'i' was not declared in this scope
    8 |   for (int i = 0; i < N; i++){
      |                   ^
Language: C++

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

int main() {
  int N;
  cin >> N;
  vector<int> num(N)
  for(int i = 0; i < N; i++){
    cin >> num.at(i);
  }
  sort(num.begin(),num.end());
  reverse(num.begin(),num.end());
  int A = 0;
  int B = 0;
  for(int i = 0; i < N; i++){
    if(i % 2 == 0)
      A += num.at(i);
    else
      B += num.at(i);
  }
  cout << A - B << endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:8:3: error: expected ',' or ';' before 'for'
    8 |   for(int i = 0; i < N; i++){
      |   ^~~
a.cc:8:18: error: 'i' was not declared in this scope
    8 |   for(int i = 0; i < N; i++){
      |                  ^
Language: C++

def solve():
    N = int(input())
    a = list(map(int, input().split()))
    a.sort(reverse=True)    #  降順で整列

    score_of_Alice = 0
    score_of_Bob = 0

    for i in range(N):
        if i % 2 == 0:
            score_of_Alice += a[i]
        else:
            score_of_Bob += a[i]

    print(score_of_Alice - score_of_Bob)

solve()

Compiler output:
a.cc:4:29: error: stray '#' in program
    4 |     a.sort(reverse=True)    #  降順で整列
      |                             ^
a.cc:1:1: error: 'def' does not name a type
    1 | def solve():
      | ^~~
Language: C++

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

int main(){
  int N,total = 0;
  cin >> N;
  vector<int> a(N);
  
  for(int i = 0;i < N;i++){
    cin >> a.at(i);
  }

  sort(a.begin(), a.end(), greater<int>())
  
  for(int i = 0;i < N;i++){
    if(i % 2 == 0){
      total += a.at(i);
    }else{
      total -= a.at(i);
    }
  }
  
  cout << total << endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:13:43: error: expected ';' before 'for'
   13 |   sort(a.begin(), a.end(), greater<int>())
      |                                           ^
      |                                           ;
   14 | 
   15 |   for(int i = 0;i < N;i++){
      |   ~~~                                      
a.cc:15:17: error: 'i' was not declared in this scope
   15 |   for(int i = 0;i < N;i++){
      |                 ^
Language: C++

#include<iostream>
using namespace std;
int main(void){
  
  int n, alice, bob;
  
  cin >> n;
  
  int a[n];
  
  for(int i = 0; i < n; i++){
    cin >> a[i];
  }
  
  a.sort();
  
  for(int i = 0; i < n; i=i+2){
    alice += a[i];
  }
  for(int i = 1; i < n; i=i+2){
    bob += a[i];
  }
  
  if(alice > bob){
    cout << alice-bob << endl;
  }else{
    cout << bob-alice << endl;
  }
  
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:15:5: error: request for member 'sort' in 'a', which is of non-class type 'int [n]'
   15 |   a.sort();
      |     ^~~~
Language: C++

#include<iostream>
using namespace std;
int main(void){
  
  int n, alice, bob;
  
  cin >> n;
  
  int a[n];
  
  for(int i = 0; i < n; i++){
    cin >> a[i];
  }
  
  a.sort();
  
  for(int i = 0; i < n; i=i+2){
    alice += a[i];
  }
  for(int i = 1; i < n; i=i+2){
    bob += a[i];
  }
  
  if(alice > bob){
    cout << alice-bob << endl;
  }else{
    cour << bob-alice << endl;
  }
  
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:15:5: error: request for member 'sort' in 'a', which is of non-class type 'int [n]'
   15 |   a.sort();
      |     ^~~~
a.cc:27:5: error: 'cour' was not declared in this scope
   27 |     cour << bob-alice << endl;
      |     ^~~~
Language: C++

#include<iostream>
using namespace std;
int main(void){
  
  int n, alice, bob;
  
  cin >> n;
  
  int a[n];
  
  for(int i = 0; i < n; i++){
    cin >> a[i];
  }
  
  a.sort();
  
  for(int i = 0; i < n; i=i+2){
    alice += s[i];
  }
  for(int i = 1; i < n; i=i+2){
    bob += s[i];
  }
  
  if(alice > bob){
    cout << alice-bob << endl;
  }else{
    cour << bob-alice << endl;
  }
  
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:15:5: error: request for member 'sort' in 'a', which is of non-class type 'int [n]'
   15 |   a.sort();
      |     ^~~~
a.cc:18:14: error: 's' was not declared in this scope
   18 |     alice += s[i];
      |              ^
a.cc:21:12: error: 's' was not declared in this scope
   21 |     bob += s[i];
      |            ^
a.cc:27:5: error: 'cour' was not declared in this scope
   27 |     cour << bob-alice << endl;
      |     ^~~~
Language: Java

import java.util.*;

public class Main {
	public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        List<Integer> cards = new ArrayList<>();
        int alliceSum = 0;
        int bobSum = 0;
        for (int i = 0; i <= n; i++) {
            cards.add(sc.nextInt());
        }
        Collections.sort(cards, Comparator.reverseOrder());

        int current = 2;
        while (cards.length > 0) {
            if (current / 2 == 0) {
                alliceSum += cards.get(0);
            } else {
                bobSum += cards.get(0);
            }
            cards.remove(0);
            current++;
        }

        System.out.println(alliceSum - bobSum);

    }
}

Compiler output:
Main.java:16: error: cannot find symbol
        while (cards.length > 0) {
                    ^
  symbol:   variable length
  location: variable cards of type List<Integer>
1 error
Language: Java

import java.util.Scanner;
import java.util.Arrays;
public class Main0{
	public static void main(String[] args){
    	Scanner sc = new Scanner(System.in);
      	int n = sc.nextInt();
      	int[] a = new int[n];
      	for(int i = 0; i < n; i++)
          a[i] = sc.nextInt();
      	Arrays.sort(a);
      	int ali, bob;
      	ali = bob = 0;
      	for(int i = 0; i < n; i++)
        	if(i % 2 == 0)
            	ali += a[i];
      		else
              	bob += a[i];
        if(ali > bob)
            System.out.println(ali-bob);
        else
            System.out.println(bob-ali);
    }
}



Compiler output:
Main.java:3: error: class Main0 is public, should be declared in a file named Main0.java
public class Main0{
       ^
1 error
Language: C++

#include <iostream>
#include <algorithm>
using namespace std;
 
 
int main() {
  int N;
  int A[110];
  
  cin >> N;
  for(int i=1;i<N;++i) cin >> A[i];
  
  sort(A,A+N,greater<int>());
  
  int Alice =0;
  int Bob =0;
    
  for (int i = 1; i <= N; ++i) {
    if (i%2 == 0) {
      Alice += A[i];
    }
    else{
      Bob += A[i];
    }
  }
  
  cout << Alice - Bob << endl;
 
  cout << res << endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:29:11: error: 'res' was not declared in this scope
   29 |   cout << res << endl;
      |           ^~~
Language: C++

#include <iostream>
#include <algorithm>
using namespace std;
 
 
int main() {
  int N;
  int A[110];
  
  cin >> N;
  for(int i=1;i<N;++i) cin >> A[i];
  
  sort(A,A+N,greater<int>());
  
  int Alice =0;
  int Bob =0;
    
  for (int i = 1; i <= N; ++i) {
    if (i%2 == 0) {
      Alice += A[i];
    }
    else{
      Bob += A[i]
    }
  }
  
  cout << Alice - Bob << endl
 
  cout << res << endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:23:18: error: expected ';' before '}' token
   23 |       Bob += A[i]
      |                  ^
      |                  ;
   24 |     }
      |     ~             
a.cc:27:30: error: expected ';' before 'cout'
   27 |   cout << Alice - Bob << endl
      |                              ^
      |                              ;
   28 | 
   29 |   cout << res << endl;
      |   ~~~~
Language: C++

#include <iostream>
using namespace std;


int main() {
  int N;
  int A[110];
  
  cin >> N;
  for(int i=1;i<N;++i) cin >> A[i];
  
  sort(A,A+N,greater<int>())
  
  int Alice =0;
  int Bob =0;
    
  for (int i = 1; i <= N; ++i) {
    if (i%2 == 0) { //  i の各桁の和が A 以上 B 以下かどうか
      Alice += a[i];
    }
    else{
      Bob += a[i]
    }
  }
  
  cout << Alice - Bob << endl

  cout << res << endl;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:12:3: error: 'sort' was not declared in this scope; did you mean 'short'?
   12 |   sort(A,A+N,greater<int>())
      |   ^~~~
      |   short
a.cc:19:7: error: 'Alice' was not declared in this scope
   19 |       Alice += a[i];
      |       ^~~~~
a.cc:19:16: error: 'a' was not declared in this scope
   19 |       Alice += a[i];
      |                ^
a.cc:22:14: error: 'a' was not declared in this scope
   22 |       Bob += a[i]
      |              ^
a.cc:26:11: error: 'Alice' was not declared in this scope
   26 |   cout << Alice - Bob << endl
      |           ^~~~~
Language: C++

#include <bits/stdc++.h>
#define rep(i,n) for (int i = 0; i < (n); ++i)
using namespace std;
typedef long long ll;
 
int main() {
  
  int N;
  cin>>N;
  
  vector<int> a(N);
  for(int i=0;i<N;i++){
        cin>>a.at(i);
    }
    sort(a.begin(), a.end(), greater<int>()); 
   
        
       
  For(int i=0; i<N; i=i+2){
      
      int alice += x.at(i);
       
       }
  
  For(int i=1; i<N; i=i+2){
      
      int bob += x.at(i);
       
       }
  
  cout<< alice - bob <<endl;
  
  
  
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:19:7: error: expected primary-expression before 'int'
   19 |   For(int i=0; i<N; i=i+2){
      |       ^~~
a.cc:19:16: error: 'i' was not declared in this scope
   19 |   For(int i=0; i<N; i=i+2){
      |                ^
a.cc:25:7: error: expected primary-expression before 'int'
   25 |   For(int i=1; i<N; i=i+2){
      |       ^~~
a.cc:31:10: error: 'alice' was not declared in this scope
   31 |   cout<< alice - bob <<endl;
      |          ^~~~~
a.cc:31:18: error: 'bob' was not declared in this scope
   31 |   cout<< alice - bob <<endl;
      |                  ^~~
Language: C++

#include <bits/stdc++.h>
#define rep(i,n) for (int i = 0; i < (n); ++i)
using namespace std;
typedef long long ll;
 
int main() {
  
  int N,a;
  cin>>N>>a;
  
  vector<int> a(N);
  for(int i=0;i<N;i++){
        cin>>a.at(i);
    }
    sort(a.begin(), a.end(), greater<int>()); 
   
        
       
  For(int i=0; i<N; i=i+2){
      
      int alice += x.at(i);
       
       }
  
  For(int i=1; i<N; i=i+2){
      
      int bob += x.at(i);
       
       }
  
  cout<< alice - bob <<endl;
  
  
  
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:11:15: error: conflicting declaration 'std::vector<int> a'
   11 |   vector<int> a(N);
      |               ^
a.cc:8:9: note: previous declaration as 'int a'
    8 |   int N,a;
      |         ^
a.cc:13:16: error: request for member 'at' in 'a', which is of non-class type 'int'
   13 |         cin>>a.at(i);
      |                ^~
a.cc:15:12: error: request for member 'begin' in 'a', which is of non-class type 'int'
   15 |     sort(a.begin(), a.end(), greater<int>());
      |            ^~~~~
a.cc:15:23: error: request for member 'end' in 'a', which is of non-class type 'int'
   15 |     sort(a.begin(), a.end(), greater<int>());
      |                       ^~~
a.cc:19:7: error: expected primary-expression before 'int'
   19 |   For(int i=0; i<N; i=i+2){
      |       ^~~
a.cc:19:16: error: 'i' was not declared in this scope
   19 |   For(int i=0; i<N; i=i+2){
      |                ^
a.cc:25:7: error: expected primary-expression before 'int'
   25 |   For(int i=1; i<N; i=i+2){
      |       ^~~
a.cc:31:10: error: 'alice' was not declared in this scope
   31 |   cout<< alice - bob <<endl;
      |          ^~~~~
a.cc:31:18: error: 'bob' was not declared in this scope
   31 |   cout<< alice - bob <<endl;
      |                  ^~~
Language: C

include <stdio.h>

void swap(int *x, int *y)
{
    int tmp;
    tmp = *x;
    *x = *y;
    *y = tmp;
}

int main(void)
{
    int i, j, N, tmp;
    int ans=0, alice=0, bob=0;
    scanf("%d", &N);

    int a[N];
    for(i=0; i<N; i++)
    {
        scanf("%d", &a[i]);
    }

    while(j<N-1)
    {
        for(i=N-1; i>j; i--)
        {
            if(a[i]>a[i-1])
            {
                swap(&a[i], &a[i-1]);
            }
        }
        j++;
    }

    for(i=0; i<N; i++)
    {
        if(i % 2 == 0)
        {
            alice += a[i];
        }
        else
        {
            bob += a[i];
        }
    }

    ans = alice - bob;

    printf("%d\n", ans);

    return 0;
}

Compiler output:
main.c:1:9: error: expected '=', ',', ';', 'asm' or '__attribute__' before '<' token
    1 | include <stdio.h>
      |         ^
main.c: In function 'main':
main.c:15:5: error: implicit declaration of function 'scanf' [-Wimplicit-function-declaration]
   15 |     scanf("%d", &N);
      |     ^~~~~
main.c:1:1: note: include '<stdio.h>' or provide a declaration of 'scanf'
  +++ |+#include <stdio.h>
    1 | include <stdio.h>
main.c:15:5: warning: incompatible implicit declaration of built-in function 'scanf' [-Wbuiltin-declaration-mismatch]
   15 |     scanf("%d", &N);
      |     ^~~~~
main.c:15:5: note: include '<stdio.h>' or provide a declaration of 'scanf'
main.c:29:17: error: implicit declaration of function 'swap' [-Wimplicit-function-declaration]
   29 |                 swap(&a[i], &a[i-1]);
      |                 ^~~~
main.c:49:5: error: implicit declaration of function 'printf' [-Wimplicit-function-declaration]
   49 |     printf("%d\n", ans);
      |     ^~~~~~
main.c:49:5: note: include '<stdio.h>' or provide a declaration of 'printf'
main.c:49:5: warning: incompatible implicit declaration of built-in function 'printf' [-Wbuiltin-declaration-mismatch]
main.c:49:5: note: include '<stdio.h>' or provide a declaration of 'printf'
Language: C++

#include <iostream>
//#include <bits/stdc++.h>
using namespace std;
int main() {
	int N , Bob, Alice, i;
	cin >> N;
	i = N;
	int a[N];
	for (i = N; i > 0; i--); {
		cin >> a[N];
	}

	std::vector<int> vec(a, a + N);//Here!
	sort(vec.begin(), vec.end());
	reverse(vec.begin(), vec.end());
	
	for (i = 0; i < N; i += 2); {
		// Alice += a[N]
		Alice += vec.at(i);
	}
	for (i = 1; i < N; i += 2); {
		// Bob += a[N]
		Bob += vec.at(i);
	}
	cout << Alice - Bob << endl;


}

Compiler output:
a.cc: In function 'int main()':
a.cc:13:14: error: 'vector' is not a member of 'std'
   13 |         std::vector<int> vec(a, a + N);//Here!
      |              ^~~~~~
a.cc:2:1: note: 'std::vector' is defined in header '<vector>'; this is probably fixable by adding '#include <vector>'
    1 | #include <iostream>
  +++ |+#include <vector>
    2 | //#include <bits/stdc++.h>
a.cc:13:21: error: expected primary-expression before 'int'
   13 |         std::vector<int> vec(a, a + N);//Here!
      |                     ^~~
a.cc:14:14: error: 'vec' was not declared in this scope
   14 |         sort(vec.begin(), vec.end());
      |              ^~~
a.cc:14:9: error: 'sort' was not declared in this scope; did you mean 'short'?
   14 |         sort(vec.begin(), vec.end());
      |         ^~~~
      |         short
a.cc:15:9: error: 'reverse' was not declared in this scope
   15 |         reverse(vec.begin(), vec.end());
      |         ^~~~~~~
Language: C++

//#include <iostream>
#include <bits/stdc++.h>
using namespace std;
int main() {
	int N , Bob, Alice, i;
	cin >> N;
	i = N;
	int a[N];
	for (i = N; i > 0; i--); {
		cin >> a[N];
	}

	std::vector<int> vec(a, a + N);//Here!
	sort(vec.begin(), vec.end());
	reverse(vec.begin(), vec.end());
	
	for (i = 0; i < N; i += 2); {
		// Alice += a[N]
			Alice += vec.at(i)
	}
	for (i = 1; i < N; i += 2); {
		// Bob += a[N]
			Bob += vec.at(i)
	}
	cout << Alice - Bob << endl;


}

Compiler output:
a.cc: In function 'int main()':
a.cc:19:43: error: expected ';' before '}' token
   19 |                         Alice += vec.at(i)
      |                                           ^
      |                                           ;
   20 |         }
      |         ~                                  
a.cc:23:41: error: expected ';' before '}' token
   23 |                         Bob += vec.at(i)
      |                                         ^
      |                                         ;
   24 |         }
      |         ~
Language: C++

#include <iostream>
using namespace std;
int main() {
	int N , Bob, Alice, i;
	cin >> N;
	i = N;
	int a[N];
	for (i = N; i > 0; i--); {
		cin >> a[N];
	}

	std::vector<int> vec(a, a + N);//Here!
	sort(vec.begin(), vec.end());
	reverse(vec.begin(), vec.end());
	
	for (i = 0; i < N; i += 2); {
		// Alice += a[N]
			Alice += vec.at(i)
	}
	for (i = 1; i < N; i += 2); {
		// Bob += a[N]
			Bob += vec.at(i)
	}
	cout << Alice - Bob << endl;


}

Compiler output:
a.cc: In function 'int main()':
a.cc:12:14: error: 'vector' is not a member of 'std'
   12 |         std::vector<int> vec(a, a + N);//Here!
      |              ^~~~~~
a.cc:2:1: note: 'std::vector' is defined in header '<vector>'; this is probably fixable by adding '#include <vector>'
    1 | #include <iostream>
  +++ |+#include <vector>
    2 | using namespace std;
a.cc:12:21: error: expected primary-expression before 'int'
   12 |         std::vector<int> vec(a, a + N);//Here!
      |                     ^~~
a.cc:13:14: error: 'vec' was not declared in this scope
   13 |         sort(vec.begin(), vec.end());
      |              ^~~
a.cc:13:9: error: 'sort' was not declared in this scope; did you mean 'short'?
   13 |         sort(vec.begin(), vec.end());
      |         ^~~~
      |         short
a.cc:14:9: error: 'reverse' was not declared in this scope
   14 |         reverse(vec.begin(), vec.end());
      |         ^~~~~~~
Language: C++

#include <iostream>
using namespace std;
int main() {
	int N , Bob, Alice, i;
	cin >> N;
	i = N;
	int a[N];
	for (i = N; i > 0; i--); {
		cin >> a[N];
	}

	vector<int> vec(a, a + N);//Here!
	sort(vec.begin(), vec.end());
	reverse(vec.begin(), vec.end());
	
	for (i = 0; i < N; i += 2); {
		// Alice += a[N]
			Alice += vec.at(i)
	}
	for (i = 1; i < N; i += 2); {
		// Bob += a[N]
			Bob += vec.at(i)
	}
	cout << Alice - Bob << endl;


}

Compiler output:
a.cc: In function 'int main()':
a.cc:12:9: error: 'vector' was not declared in this scope
   12 |         vector<int> vec(a, a + N);//Here!
      |         ^~~~~~
a.cc:2:1: note: 'std::vector' is defined in header '<vector>'; this is probably fixable by adding '#include <vector>'
    1 | #include <iostream>
  +++ |+#include <vector>
    2 | using namespace std;
a.cc:12:16: error: expected primary-expression before 'int'
   12 |         vector<int> vec(a, a + N);//Here!
      |                ^~~
a.cc:13:14: error: 'vec' was not declared in this scope
   13 |         sort(vec.begin(), vec.end());
      |              ^~~
a.cc:13:9: error: 'sort' was not declared in this scope; did you mean 'short'?
   13 |         sort(vec.begin(), vec.end());
      |         ^~~~
      |         short
a.cc:14:9: error: 'reverse' was not declared in this scope
   14 |         reverse(vec.begin(), vec.end());
      |         ^~~~~~~