Language: C++

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

int main(){
  string s;
  cin >> s;
  
  vector<char> A = {a, b, c, d, e, f, g, h, i, j, k, l, m, o, p, q, r, s, t,
                   u, v, w, x, y, z};
  bool x = true;
  for(int i = 0; i < 26; i++){
    if(count(s.begin(), s.end(), A[i]) % 2 == 1){
      x = false;
      break;
    }
  }
  if(x){
    cout << "Yes" << endl;
  }
  else{
    cout << "No" << endl;
  }
  
 
}

  
    
      
              
    

Compiler output:
a.cc: In function 'int main()':
a.cc:8:21: error: 'a' was not declared in this scope
    8 |   vector<char> A = {a, b, c, d, e, f, g, h, i, j, k, l, m, o, p, q, r, s, t,
      |                     ^
a.cc:8:24: error: 'b' was not declared in this scope
    8 |   vector<char> A = {a, b, c, d, e, f, g, h, i, j, k, l, m, o, p, q, r, s, t,
      |                        ^
a.cc:8:27: error: 'c' was not declared in this scope
    8 |   vector<char> A = {a, b, c, d, e, f, g, h, i, j, k, l, m, o, p, q, r, s, t,
      |                           ^
a.cc:8:30: error: 'd' was not declared in this scope
    8 |   vector<char> A = {a, b, c, d, e, f, g, h, i, j, k, l, m, o, p, q, r, s, t,
      |                              ^
a.cc:8:33: error: 'e' was not declared in this scope
    8 |   vector<char> A = {a, b, c, d, e, f, g, h, i, j, k, l, m, o, p, q, r, s, t,
      |                                 ^
a.cc:8:36: error: 'f' was not declared in this scope
    8 |   vector<char> A = {a, b, c, d, e, f, g, h, i, j, k, l, m, o, p, q, r, s, t,
      |                                    ^
a.cc:8:39: error: 'g' was not declared in this scope
    8 |   vector<char> A = {a, b, c, d, e, f, g, h, i, j, k, l, m, o, p, q, r, s, t,
      |                                       ^
a.cc:8:42: error: 'h' was not declared in this scope
    8 |   vector<char> A = {a, b, c, d, e, f, g, h, i, j, k, l, m, o, p, q, r, s, t,
      |                                          ^
a.cc:8:45: error: 'i' was not declared in this scope
    8 |   vector<char> A = {a, b, c, d, e, f, g, h, i, j, k, l, m, o, p, q, r, s, t,
      |                                             ^
a.cc:8:48: error: 'j' was not declared in this scope
    8 |   vector<char> A = {a, b, c, d, e, f, g, h, i, j, k, l, m, o, p, q, r, s, t,
      |                                                ^
a.cc:8:51: error: 'k' was not declared in this scope
    8 |   vector<char> A = {a, b, c, d, e, f, g, h, i, j, k, l, m, o, p, q, r, s, t,
      |                                                   ^
a.cc:8:54: error: 'l' was not declared in this scope
    8 |   vector<char> A = {a, b, c, d, e, f, g, h, i, j, k, l, m, o, p, q, r, s, t,
      |                                                      ^
a.cc:8:57: error: 'm' was not declared in this scope
    8 |   vector<char> A = {a, b, c, d, e, f, g, h, i, j, k, l, m, o, p, q, r, s, t,
      |                                                         ^
a.cc:8:60: error: 'o' was not declared in this scope
    8 |   vector<char> A = {a, b, c, d, e, f, g, h, i, j, k, l, m, o, p, q, r, s, t,
      |                                                            ^
a.cc:8:63: error: 'p' was not declared in this scope
    8 |   vector<char> A = {a, b, c, d, e, f, g, h, i, j, k, l, m, o, p, q, r, s, t,
      |                                                               ^
a.cc:8:66: error: 'q' was not declared in this scope
    8 |   vector<char> A = {a, b, c, d, e, f, g, h, i, j, k, l, m, o, p, q, r, s, t,
      |                                                                  ^
a.cc:8:69: error: 'r' was not declared in this scope
    8 |   vector<char> A = {a, b, c, d, e, f, g, h, i, j, k, l, m, o, p, q, r, s, t,
      |                                                                     ^
a.cc:8:75: error: 't' was not declared in this scope
    8 |   vector<char> A = {a, b, c, d, e, f, g, h, i, j, k, l, m, o, p, q, r, s, t,
      |                                                                           ^
a.cc:9:20: error: 'u' was not declared in this scope
    9 |                    u, v, w, x, y, z};
      |                    ^
a.cc:9:23: error: 'v' was not declared in this scope
    9 |                    u, v, w, x, y, z};
      |                       ^
a.cc:9:26: error: 'w' was not declared in this scope
    9 |                    u, v, w, x, y, z};
      |                          ^
a.cc:9:29: error: 'x' was not declared in this scope
    9 |                    u, v, w, x, y, z};
      |                             ^
a.cc:9:32: error: 'y' was not declared in this scope
    9 |                    u, v, w, x, y, z};
      |                                ^
a.cc:9:35: error: 'z' was not declared in this scope
    9 |                    u, v, w, x, y, z};
      |                                   ^
a.cc:9:36: error: could not convert '{<expression error>, <expression error>, <expression error>, <expression error>, <expression error>, <expression error>, <expression error>, <expression error>, <expression error>, <expression error>, <expression error>, <expression error>, <expression error>, <expression error>, <expression error>, <expression error>, <expression error>, s, <expression error>, <expression error>, <expression error>, <expression error>, <expression error>, <expression error>, <expression error>}' from '<brace-enclosed initializer list>' to 'std::vector<char>'
    9 |                    u, v, w, x, y, z};
      |                                    ^
      |                                    |
      |                                    <brace-enclosed initializer list>