Language: C++

#include <algorithm>
#include <iostream>
#include <vector>
#include <queue>
#include <set>
#include <map>
#include <list>
#include <cmath>
#include <stack>
#include <string>
#include <cstring>
#include <numeric>
#include <iomanip>
#include <fstream>
using namespace std;
int main(){
	int n,a,b,c;
	cin>>n>>a>>b>>c;
	vector<char> ans;
	string s[100000];
	for(int i=0;i<n;i++){
		cin>>s[i];
	}
	for(int i=0;i<n;i++){
		if(s[i]=="AB"){
			if(a==0&&b==0){
				cout<<"No"<<endl;
				return 0;
			}else if(a<b){
				ans.push_back('A');	
				a++;
				b--;
			}else if(a>b){
				ans.push_back('B');
				a--;
				b++;
			}else{
				if(i==n-1){
					ans.push_back('A');
					a++;
					b--;
				}else if(s[i+1]=='AB'){
					ans.push_back('A');
					a++;
					b--;
				}else if(s[i+1]=='BC'){
					ans.push_back('B');
					a--;
					b++;
				}else{
					ans.push_back('A');
					a++;
					c--;
				}
			}
		}else if(s[i]=="BC"){
			if(b==0&&c==0){
				cout<<"No"<<endl;
				return 0;
			}else if(b<c){
				ans.push_back('B');
				b++;
				c--;
			}else if(b>c){
				ans.push_back('C');
				b--;
				c++;
			}else{
				if(i==n-1){
					ans.push_back('B');
					b++;
					c--;
				}else if(s[i+1]=='AB'){
					ans.push_back('B');
					b++;
					c--;
				}else if(s[i+1]=='BC'){
					ans.push_back('B');
					b++;
					c--;
				}else{
					ans.push_back('C');
					b--;
					c++;
				}
			}
		}else{
			if(a==0&&c==0){
				cout<<"No"<<endl;
				return 0;
			}else if(a<c){
				ans.push_back('A');
				a++;
				c--;
			}else if(a>c){
				ans.push_back('C');
				a--;
				c++;
			}else{
				if(i==n-1){
					ans.push_back('A');
					a++;
					c--;
				}else if(s[i+1]=='AB'){
					ans.push_back('A');
					a++;
					c--;
				}else if(s[i+1]=='BC'){
					ans.push_back('C');
					a--;
					c++;
				}else{
					ans.push_back('A');
					a++;
					c--;
				}

			}
		}
//		if(a<0||b<0||c<0){
//			cout<<"out"<<endl;
//		}
	}
	cout<<"Yes"<<endl;
	for(int i=0;i<ans.size();i++){
		cout<<ans[i]<<endl;
	}
	return 0;
}

Compiler output:
a.cc:42:50: warning: multi-character character constant [-Wmultichar]
   42 |                                 }else if(s[i+1]=='AB'){
      |                                                  ^~~~
a.cc:46:50: warning: multi-character character constant [-Wmultichar]
   46 |                                 }else if(s[i+1]=='BC'){
      |                                                  ^~~~
a.cc:73:50: warning: multi-character character constant [-Wmultichar]
   73 |                                 }else if(s[i+1]=='AB'){
      |                                                  ^~~~
a.cc:77:50: warning: multi-character character constant [-Wmultichar]
   77 |                                 }else if(s[i+1]=='BC'){
      |                                                  ^~~~
a.cc:104:50: warning: multi-character character constant [-Wmultichar]
  104 |                                 }else if(s[i+1]=='AB'){
      |                                                  ^~~~
a.cc:108:50: warning: multi-character character constant [-Wmultichar]
  108 |                                 }else if(s[i+1]=='BC'){
      |                                                  ^~~~
a.cc: In function 'int main()':
a.cc:42:48: error: no match for 'operator==' (operand types are 'std::string' {aka 'std::__cxx11::basic_string<char>'} and 'int')
   42 |                                 }else if(s[i+1]=='AB'){
      |                                          ~~~~~~^~~~~~
      |                                               |  |
      |                                               |  int
      |                                               std::string {aka std::__cxx11::basic_string<char>}
In file included from /usr/include/c++/14/bits/stl_algobase.h:64,
                 from /usr/include/c++/14/algorithm:60,
                 from a.cc:1:
/usr/include/c++/14/bits/stl_pair.h:1033:5: note: candidate: 'template<class _T1, class _T2> constexpr bool std::operator==(const pair<_T1, _T2>&, const pair<_T1, _T2>&)'
 1033 |     operator==(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_pair.h:1033:5: note:   template argument deduction/substitution failed:
a.cc:42:50: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::pair<_T1, _T2>'
   42 |                                 }else if(s[i+1]=='AB'){
      |                                                  ^~~~
In file included from /usr/include/c++/14/bits/stl_algobase.h:67:
/usr/include/c++/14/bits/stl_iterator.h:441:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator==(const reverse_iterator<_Iterator>&, const reverse_iterator<_Iterator>&)'
  441 |     operator==(const reverse_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:441:5: note:   template argument deduction/substitution failed:
a.cc:42:50: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::reverse_iterator<_Iterator>'
   42 |                                 }else if(s[i+1]=='AB'){
      |                                                  ^~~~
/usr/include/c++/14/bits/stl_iterator.h:486:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator==(const reverse_iterator<_Iterator>&, const reverse_iterator<_IteratorR>&)'
  486 |     operator==(const reverse_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:486:5: note:   template argument deduction/substitution failed:
a.cc:42:50: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::reverse_iterator<_Iterator>'
   42 |                                 }else if(s[i+1]=='AB'){
      |                                                  ^~~~
/usr/include/c++/14/bits/stl_iterator.h:1667:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator==(const move_iterator<_IteratorL>&, const move_iterator<_IteratorR>&)'
 1667 |     operator==(const move_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1667:5: note:   template argument deduction/substitution failed:
a.cc:42:50: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::move_iterator<_IteratorL>'
   42 |                                 }else if(s[i+1]=='AB'){
      |                                                  ^~~~
/usr/include/c++/14/bits/stl_iterator.h:1737:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator==(const move_iterator<_IteratorL>&, const move_iterator<_IteratorL>&)'
 1737 |     operator==(const move_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1737:5: note:   template argument deduction/substitution failed:
a.cc:42:50: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::move_iterator<_IteratorL>'
   42 |                                 }else if(s[i+1]=='AB'){
      |                                                  ^~~~
In file included from /usr/include/c++/14/iosfwd:42,
                 from /usr/include/c++/14/ios:40,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41,
                 from a.cc:2:
/usr/include/c++/14/bits/postypes.h:192:5: note: candidate: 'template<class _StateT> bool std::operator==(const fpos<_StateT>&, const fpos<_StateT>&)'
  192 |     operator==(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
      |     ^~~~~~~~
/usr/include/c++/14/bits/postypes.h:192:5: note:   template argument deduction/substitution failed:
a.cc:42:50: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::fpos<_StateT>'
   42 |                                 }else if(s[i+1]=='AB'){
      |                                                  ^~~~
In file included from /usr/include/c++/14/string:43,
                 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/bits/allocator.h:235:5: note: candidate: 'template<class _T1, class _T2> bool std::operator==(const allocator<_CharT>&, const allocator<_T2>&)'
  235 |     operator==(const allocator<_T1>&, const allocator<_T2>&)
      |     ^~~~~~~~
/usr/include/c++/14/bits/allocator.h:235:5: note:   template argument deduction/substitution failed:
a.cc:42:50: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::allocator<_CharT>'
   42 |                                 }else if(s[i+1]=='AB'){
      |                                                  ^~~~
In file included from /usr/include/c++/14/bits/basic_string.h:47,
                 from /usr/include/c++/14/string:54:
/usr/include/c++/14/string_view:629:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator==(basic_string_view<_CharT, _Traits>, __type_identity_t<basic_string_view<_CharT, _Traits> >)'
  629 |     operator==(basic_string_view<_CharT, _Traits> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:629:5: note:   template argument deduction/substitution failed:
a.cc:42:50: note:   'std::__cxx11::basic_string<char>' is not derived from 'std::basic_string_view<_CharT, _Traits>'
   42 |                                 }else if(s[i+1]=='AB'){
      |                                                  ^~~~
/usr/include/c++/14/string_view:637:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator==(basic_string_view<_CharT, _Traits>, basic_string_view<_CharT, _Traits>)'
  637 |     operator==(basic_string_view<_CharT, _Traits> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:637:5: note:   template argument deduction/substitution failed:
a.cc:42:50: note:   'std::__cxx11::basic_string<char>' is not derived from 'std::basic_string_view<_CharT, _Traits>'
   42 |                                 }else if(s[i+1]=='AB'){
      |                                                  ^~~~
/usr/include/c++/14/string_view:644:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator==(__type_identity_t<basic_string_view<_CharT, _Traits> >, basic_string_view<_CharT, _Traits>)'
  644 |     operator==(__type_identity_t<basic_string_view<_CharT, _Traits>> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:644:5: note:   template argument deduction/substitution failed:
a.cc:42:50: note:   mismatched types 'std::basic_string_view<_CharT, _Traits>' and 'int'
   42 |                                 }else if(s[i+1]=='AB'){
      |                                                  ^~~~
/usr/include/c++/14/bits/basic_string.h:3755:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3755 |     operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3755:5: note:   template argument deduction/substitution failed:
a.cc:42:50: note:   mismatched types 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>' and 'int'
   42 |                                 }else if(s[i+1]=='AB'){
      |                                                  ^~~~
/usr/include/c++/14/bits/basic_string.h:3772:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, const _CharT*)'
 3772 |     operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3772:5: note:   template argument deduction/substitution failed:
a.cc:42:50: note:   mismatched types 'const _CharT*' and 'int'
   42 |                                 }else if(s[i+1]=='AB'){
      |                                                  ^~~~
/usr/include/c++/14/bits/basic_string.h:3819:5: note: candidate: 'template<class _CharT, class _Traits, class