Language: C++

#include <bits/stdc++.h>
#define rep(i, a, n) for(int i = a; i < n; i++)
#define REP(i, n) rep(i, 0, n)
#define repb(i, a, b) for(int i = a; i >= b; i--)
#define all(a) a.begin(), a.end()
#define int long long
#define chmax(x, y) x = max(x, y)
#define chmin(x, y) x = min(x, y)
using namespace std;
typedef pair<int, int> P;
const int mod = 1000000007;
const int INF = 1e12;

signed main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    string s;
    cin >> s;
    char now = s[0];
    int cnt = 1;
    s += "!";
    vector<int> a;
    rep(i, 1, s.size()){
        if(s[i] == now){
            cnt++;
        }else{
            a.push_back(i);
            // a.push_back(cnt);
            cnt = 1;
            now = s[i];
        }
    }
    // for(int ii = 0; ii < a.size(); ii++){
    //     if(ii) cout << ' ';
    //     cout << a[ii];
    // }
    // cout << endl;
    int ans = INF;
    if(a.size() == 1){
        ans = s.size() - 1;
    }else{
        rep(i, 0, a.size()){
            chmin(ans, max(a[i], s.size() - 1 - a[i]));
        }
    }
    cout << ans << endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:43:27: error: no matching function for call to 'max(__gnu_cxx::__alloc_traits<std::allocator<long long int>, long long int>::value_type&, long long unsigned int)'
   43 |             chmin(ans, max(a[i], s.size() - 1 - a[i]));
      |                        ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
a.cc:8:32: note: in definition of macro 'chmin'
    8 | #define chmin(x, y) x = min(x, y)
      |                                ^
In file included from /usr/include/c++/14/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:51,
                 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:43:27: note:   deduced conflicting types for parameter 'const _Tp' ('long long int' and 'long long unsigned int')
   43 |             chmin(ans, max(a[i], s.size() - 1 - a[i]));
      |                        ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
a.cc:8:32: note: in definition of macro 'chmin'
    8 | #define chmin(x, y) x = min(x, y)
      |                                ^
/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:43:27: note:   mismatched types 'std::initializer_list<_Tp>' and 'long long int'
   43 |             chmin(ans, max(a[i], s.size() - 1 - a[i]));
      |                        ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
a.cc:8:32: note: in definition of macro 'chmin'
    8 | #define chmin(x, y) x = min(x, y)
      |                                ^