Language: C++

#include <iostream> // cout, endl, cin
#include <string> // string, to_string, stoi
#include <vector> // vector
#include <algorithm> // min, max, swap, sort, reverse, lower_bound, upper_bound
#include <utility> // pair, make_pair
#include <tuple> // tuple, make_tuple
#include <cstdint> // int64_t, int*_t
#include <cstdio> // printf
#include <map> // map
#include <queue> // queue, priority_queue
#include <set> // set
#include <stack> // stack
#include <deque> // deque
#include <unordered_map> // unordered_map
#include <unordered_set> // unordered_set
#include <bitset> // bitset
#include <cctype> // isupper, islower, isdigit, toupper, tolower
#include<math.h>
#include<iomanip>
#include<functional>
using namespace std;

#define ll long long
using vt = ll; //ここで数値の型を変えられる
#define rep(i, n) for (vt i = 0; i < (vt)(n); i++)
#define reps(i, s, n) for(vt i = (vt) (s); i < (vt) (n); i++) 
#define all(v) v.begin(), v.end()
#define P pair<ll, ll>
const ll  MOD = 1000000007;

int main() {
	string s;
	cin >> s;
	ll cnt = 0;
	rep(i, s.size()) {
		if (s.at(i) == '0') cnt ++;
	}
	cout << 2 * min(cnt, s.size() - cnt);
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:38:24: error: no matching function for call to 'min(long long int&, long long unsigned int)'
   38 |         cout << 2 * min(cnt, s.size() - cnt);
      |                     ~~~^~~~~~~~~~~~~~~~~~~~~
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:38:24: note:   deduced conflicting types for parameter 'const _Tp' ('long long int' and 'long long unsigned int')
   38 |         cout << 2 * min(cnt, s.size() - cnt);
      |                     ~~~^~~~~~~~~~~~~~~~~~~~~
/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:4:
/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:38:24: note:   mismatched types 'std::initializer_list<_Tp>' and 'long long int'
   38 |         cout << 2 * min(cnt, s.size() - cnt);
      |                     ~~~^~~~~~~~~~~~~~~~~~~~~