Language: C++

#include<iostream>
#include<string>
#include<cmath>
#include<queue>
#include<map>
#include<set>
#include<list>
#include<iomanip>
#include<vector>
#include<random>
#include<functional>
#include<algorithm>
#include<cstdio>
#include<unordered_map>
using namespace std;
//---------------------------------------------------
//ライブラリゾーン！！！！
//#define int long long
#define str string
#define rep(i,j) for(int i=0;i<(int)(j);i++)
typedef long long ll;
typedef long double ld;
const long long inf = 4523372036854775807;
const ll Mod = 1000000007;
const ll gosenchou = 5000000000000000;
short gh[2][4] = { { 0,0,-1,1 },{ -1,1,0,0 } };
struct P {
	ll pos, cost;
};
bool operator<(P a, P b) { return a.cost < b.cost; }
bool operator>(P a, P b) { return a.cost > b.cost; }
struct B {//隣接リスト表現
	ll to, cost;
};
struct E {//辺の情報を入れる変数
	int from, to, cost;
};
bool operator<(E a, E b) {
	return a.cost < b.cost;
}
struct H {
	int x, y;
};
bool operator<(H a, H b) {
	if (a.x != b.x) return a.x < b.x;
	return a.y < b.y;
}
bool operator>(H a, H b) {
	if (a.x != b.x) return a.x > b.x;
	return a.y > b.y;
}
bool operator==(H a, H b) {
	return a.x == b.x&&a.y == b.y;
}
bool operator!=(H a, H b) {
	return a.x != b.x || a.y != b.y;
}
ll gcm(ll i, ll j) {//最大公約数
	if (i > j) swap(i, j);
	if (i == 0) return j;
	return gcm(j%i, i);
}
ld rad(H a, H b) {
	return sqrt(pow(a.x - b.x, 2.0) + pow(a.y - b.y, 2.0));
}//rad＝座標上の2点間の距離
int ari(int a, int b, int c) {
	return (a + b)*c / 2;
}//等差数列の和
bool suf(ld a, ld b, ld c, ld d) {
	if (b <= c || d <= a) return 0;
	return 1;
}//[a,b),[c,d)
int fact(int i) {
	int sum = 1;
	for (int j = 2; j <= i; j++)
		sum = (sum* j) % Mod;
	return sum;
}//階乗(正）
//---------------------------------------------------
//+++++++++++++++++++++++++++++++++++++++++++++++++++
bool a[100000];
int main() {
	string s;
	cin >> s;
	int sum = 0;
	for (int i = 0; i < s.size(); i++) {
		if (s[i] != '0')
			a[i] = 1;
	}
	int ans = 0;
	for (int i = 0; i < s.size() - 1; i++) {
		if (a[i] != a[i + 1]) {
			ans = max(ans, max(i + 1, (s.size() - i - 1)));
		}
	}
	cout << ans << endl;
	getchar(); getchar();
}

Compiler output:
a.cc: In function 'int main()':
a.cc:93:43: error: no matching function for call to 'max(int, std::__cxx11::basic_string<char>::size_type)'
   93 |                         ans = max(ans, max(i + 1, (s.size() - i - 1)));
      |                                        ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
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: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:93:43: note:   deduced conflicting types for parameter 'const _Tp' ('int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'})
   93 |                         ans = max(ans, max(i + 1, (s.size() - i - 1)));
      |                                        ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
/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,
                 from a.cc:12:
/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:93:43: note:   mismatched types 'std::initializer_list<_Tp>' and 'int'
   93 |                         ans = max(ans, max(i + 1, (s.size() - i - 1)));
      |                                        ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~