Language: C++

#include<iostream>
#include<algorithm>
#include<cstring>
#include<math.h>
#include<queue>
#include<deque>
#include<map>
#include<set>
#include<vector>
int az[26];
using namespace std;
int main() {
	
	string s;
	int n;
	cin >> n;
	int i,j;
	
	for (j = 0; j < 26; j++) {
		az[j] = 100;
	}
	for (i = 0; i < n; i++) {
		cin >> s;
		for (j = 0; j < 26; j++) {
			az[j] = min(count(s.cbegin(), s.cend(), 'a' + j), az[j]);
		}
	}
	char c;
	for (i = 0; i < 26; i++) {
		for (j = 0; j < az[i]; j++) {
			c =  'a' + i;
			cout << c;	
		}
	}
	cout << endl;
	return 0;

}

Compiler output:
a.cc: In function 'int main()':
a.cc:25:36: error: no matching function for call to 'min(std::__iterator_traits<__gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >, void>::difference_type, int&)'
   25 |                         az[j] = min(count(s.cbegin(), s.cend(), 'a' + j), az[j]);
      |                                 ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/14/string:51,
                 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,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41,
                 from a.cc:1:
/usr/include/c++/14/bits/stl_algobase.h:233:5: note: candidate: 'template<class _Tp> constexpr const _Tp& std::min(const _Tp&, const _Tp&)'
  233 |     min(const _Tp& __a, const _Tp& __b)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:233:5: note:   template argument deduction/substitution failed:
a.cc:25:36: note:   deduced conflicting types for parameter 'const _Tp' ('long int' and 'int')
   25 |                         az[j] = min(count(s.cbegin(), s.cend(), 'a' + j), az[j]);
      |                                 ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algobase.h:281:5: note: candidate: 'template<class _Tp, class _Compare> constexpr const _Tp& std::min(const _Tp&, const _Tp&, _Compare)'
  281 |     min(const _Tp& __a, const _Tp& __b, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:281:5: note:   candidate expects 3 arguments, 2 provided
In file included from /usr/include/c++/14/algorithm:61,
                 from a.cc:2:
/usr/include/c++/14/bits/stl_algo.h:5686:5: note: candidate: 'template<class _Tp> constexpr _Tp std::min(initializer_list<_Tp>)'
 5686 |     min(initializer_list<_Tp> __l)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5686:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_algo.h:5696:5: note: candidate: 'template<class _Tp, class _Compare> constexpr _Tp std::min(initializer_list<_Tp>, _Compare)'
 5696 |     min(initializer_list<_Tp> __l, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5696:5: note:   template argument deduction/substitution failed:
a.cc:25:36: note:   mismatched types 'std::initializer_list<_Tp>' and 'long int'
   25 |                         az[j] = min(count(s.cbegin(), s.cend(), 'a' + j), az[j]);
      |                                 ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~