Language: C++

#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <locale>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <typeinfo>
#include <utility>
#include <valarray>
#include <vector>
#define rep(i,a,n) for(ll i =(a);i<(n);i++)
#define urep(i,a,n) for(ll i = (a);i>=(n);i--)
#define all(x) (x).begin(),(x).end()
#define INF 1e9
const int mod = 1e9 + 7;
typedef long long ll;
using namespace std;
ll dx[4] = { 1,-1,0,0 };
ll dy[4] = { 0,0,1,-1 };
ll N, M, Q, H, W, D, L, R, K, X;
ll A;
ll B;
ll ans;
string S;
bool Prime[100001];
ll anstable[100001];
ll gcd(ll a, ll b) {
	if (b == 0)return a;
	else return gcd(b, a%b);
}
int main() {
	cin >> S;
	ans = INF;
	char oldnum = S[0];
	rep(i, 1, S.size()) {
		if (S[i] != oldnum) {
			ans = min(ans, max(i, S.size() - i));
		}
		oldnum = S[i];
	}
	
	cout << ans << endl;
	cin >> ans;
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:59:43: error: no matching function for call to 'max(ll&, long long unsigned int)'
   59 |                         ans = min(ans, max(i, S.size() - i));
      |                                        ~~~^~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/14/algorithm:60,
                 from a.cc:1:
/usr/include/c++/14/bits/stl_algobase.h:257:5: note: candidate: 'template<class _Tp> constexpr const _Tp& std::max(const _Tp&, const _Tp&)'
  257 |     max(const _Tp& __a, const _Tp& __b)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:257:5: note:   template argument deduction/substitution failed:
a.cc:59:43: note:   deduced conflicting types for parameter 'const _Tp' ('long long int' and 'long long unsigned int')
   59 |                         ans = min(ans, max(i, S.size() - i));
      |                                        ~~~^~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note: candidate: 'template<class _Tp, class _Compare> constexpr const _Tp& std::max(const _Tp&, const _Tp&, _Compare)'
  303 |     max(const _Tp& __a, const _Tp& __b, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note:   candidate expects 3 arguments, 2 provided
In file included from /usr/include/c++/14/algorithm:61:
/usr/include/c++/14/bits/stl_algo.h:5706:5: note: candidate: 'template<class _Tp> constexpr _Tp std::max(initializer_list<_Tp>)'
 5706 |     max(initializer_list<_Tp> __l)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5706:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_algo.h:5716:5: note: candidate: 'template<class _Tp, class _Compare> constexpr _Tp std::max(initializer_list<_Tp>, _Compare)'
 5716 |     max(initializer_list<_Tp> __l, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5716:5: note:   template argument deduction/substitution failed:
a.cc:59:43: note:   mismatched types 'std::initializer_list<_Tp>' and 'long long int'
   59 |                         ans = min(ans, max(i, S.size() - i));
      |                                        ~~~^~~~~~~~~~~~~~~~~