Language: C++

#include<iostream>
#include<string>
#include<cstdio>
#include<vector>
#include<cmath>
#include<algorithm>
#include<functional>
#include<iomanip>
#include<queue>
#include<ciso646>
#include<random>
#include<map>
#include<set>
#include<bitset>
#include<stack>
#include<unordered_map>
#include<utility>
#include<cassert>
#include<complex>
#include<numeric>
#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef unsigned long long ul;
typedef unsigned int ui;
typedef pair<int, int>P;
typedef pair<ll, ll> LP;
typedef long double ld;
typedef pair<ld, ld> LDP;
typedef vector<vector<ll>> mat;
typedef vector<ll> vec;
#define stop char nyaa;cin>>nyaa;
#define rep(i,n) for(int i=0;i<n;i++)
#define per(i,n) for(int i=n-1;i>=0;i--)
#define Rep(i,sta,n) for(int i=sta;i<n;i++)
#define rep1(i,n) for(int i=1;i<=n;i++)
#define per1(i,n) for(int i=n;i>=1;i--)
#define Rep1(i,sta,n) for(int i=sta;i<=n;i++)
#define all(v) (v).begin(),(v).end()
const ll mod = 1000000007;
const ll INF = mod * mod;
const ld eps = 1e-12;
const ld pi = acos(-1.0);
//int qp(int a,ll b){int ans=1;do{if(b&1)ans=1ll*ans*a%mo;a=1ll*a*a%mo;}while(b>>=1);return ans;}
ll qp(ll a,ll b,int mo){int ans=1;do{if(b&1)ans=1ll*ans*a%mo;a=1ll*a*a%mo;}while(b>>=1);return ans;}
ll gcd(ll a,ll b){return b?gcd(b,a%b):a;} // 最大公約数
ll lcm (ll a, ll b){return a/gcd(a,b)*b;} // 最小公倍数
int dx[4] = { 0,1,0,-1 };
int dy[4] = { 1,0,-1,0 };

template<typename T> istream &operator>>(istream &is, vector<T> &vec){ for (auto &v : vec) is >> v; return is; }
template<typename T> ostream &operator<<(ostream &os, const vector<T> &vec){ os << "["; for (auto v : vec) os << v << ","; os << "]"; return os; }
template<typename T> ostream &operator<<(ostream &os, const deque<T> &vec){ os << "deq["; for (auto v : vec) os << v << ","; os << "]"; return os; }
template<typename T> ostream &operator<<(ostream &os, const set<T> &vec){ os << "{"; for (auto v : vec) os << v << ","; os << "}"; return os; }
template<typename T> ostream &operator<<(ostream &os, const unordered_set<T> &vec){ os << "{"; for (auto v : vec) os << v << ","; os << "}"; return os; }
template<typename T> ostream &operator<<(ostream &os, const multiset<T> &vec){ os << "{"; for (auto v : vec) os << v << ","; os << "}"; return os; }
template<typename T> ostream &operator<<(ostream &os, const unordered_multiset<T> &vec){ os << "{"; for (auto v : vec) os << v << ","; os << "}"; return os; }
template<typename T1, typename T2> ostream &operator<<(ostream &os, const pair<T1, T2> &pa){ os << "(" << pa.first << "," << pa.second << ")"; return os; }
template<typename TK, typename TV> ostream &operator<<(ostream &os, const map<TK, TV> &mp){ os << "{"; for (auto v : mp) os << v.first << "=>" << v.second << ","; os << "}"; return os; }
template<typename TK, typename TV> ostream &operator<<(ostream &os, const unordered_map<TK, TV> &mp){ os << "{"; for (auto v : mp) os << v.first << "=>" << v.second << ","; os << "}"; return os; }
template<typename T> void ndarray(vector<T> &vec, int len) { vec.resize(len); }
template<typename T, typename... Args> void ndarray(vector<T> &vec, int len, Args... args) { vec.resize(len); for (auto &v : vec) ndarray(v, args...); }
template<typename T> bool chmax(T &m, const T q) { if (m < q) {m = q; return true;} else return false; }
template<typename T> bool chmin(T &m, const T q) { if (q < m) {m = q; return true;} else return false; }
template<typename T1, typename T2> pair<T1, T2> operator+(const pair<T1, T2> &l, const pair<T1, T2> &r) { return make_pair(l.first + r.first, l.second + r.second); }
template<typename T1, typename T2> pair<T1, T2> operator-(const pair<T1, T2> &l, const pair<T1, T2> &r) { return make_pair(l.first - r.first, l.second - r.second); }



void solve() {
    ll N;
    cin >> N;
    string S;
    cin >> S;

    set<ll> R;
    set<ll> G;
    set<ll> B;

    ll co = 0;

    rep1(i,N){
        if(S[i-1] == 'R') R.insert(i);
        else if(S[i-1] == 'G') G.insert(i);
        else if(S[i-1] == 'B') B.insert(i);
    }

    if(R.empty() || G.empty() || B || empty){
        co = 0;
    }
    else{
        for(auto r: R){
            for(auto g: G){
                for(auto b: B){
                    ll i,j,k;
                    k = max(r,max(g,b));
                    i = min(r,min(g,b));
                    j = r+g+b-i-k;
                    if(j-i != k-j)co++;
                }
            }
        }
    }

    cout << co << endl;

}

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(0);

    cout << fixed << setprecision(10);
    solve();
    // stop
        return 0;
}

Compiler output:
a.cc: In function 'void solve()':
a.cc:89:31: error: no match for 'operator||' (operand types are 'bool' and 'std::set<long long int>')
   89 |     if(R.empty() || G.empty() || B || empty){
      |        ~~~~~~~~~~~~~~~~~~~~~~ ^~ ~
      |                  |               |
      |                  bool            std::set<long long int>
a.cc:89:31: note: candidate: 'operator||(bool, bool)' (built-in)
   89 |     if(R.empty() || G.empty() || B || empty){
      |        ~~~~~~~~~~~~~~~~~~~~~~~^~~~
a.cc:89:31: note:   no known conversion for argument 2 from 'std::set<long long int>' to 'bool'
In file included from /usr/include/c++/14/valarray:605,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:166,
                 from a.cc:21:
/usr/include/c++/14/bits/valarray_after.h:416:5: note: candidate: 'template<class _Dom1, class _Dom2> std::_Expr<std::__detail::_BinClos<std::__logical_or, std::_Expr, std::_Expr, _Dom1, _Dom2>, typename std::__fun<std::__logical_or, typename _Dom1::value_type>::result_type> std::operator||(const _Expr<_Dom1, typename _Dom1::value_type>&, const _Expr<_Dom2, typename _Dom2::value_type>&)'
  416 |     _DEFINE_EXPR_BINARY_OPERATOR(||, struct std::__logical_or)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:416:5: note:   template argument deduction/substitution failed:
a.cc:89:34: note:   mismatched types 'const std::_Expr<_Dom1, typename _Dom1::value_type>' and 'bool'
   89 |     if(R.empty() || G.empty() || B || empty){
      |                                  ^
/usr/include/c++/14/bits/valarray_after.h:416:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__logical_or, std::_Expr, std::_Constant, _Dom, typename _Dom::value_type>, typename std::__fun<std::__logical_or, typename _Dom1::value_type>::result_type> std::operator||(const _Expr<_Dom1, typename _Dom1::value_type>&, const typename _Dom::value_type&)'
  416 |     _DEFINE_EXPR_BINARY_OPERATOR(||, struct std::__logical_or)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:416:5: note:   template argument deduction/substitution failed:
a.cc:89:34: note:   mismatched types 'const std::_Expr<_Dom1, typename _Dom1::value_type>' and 'bool'
   89 |     if(R.empty() || G.empty() || B || empty){
      |                                  ^
/usr/include/c++/14/bits/valarray_after.h:416:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__logical_or, std::_Constant, std::_Expr, typename _Dom::value_type, _Dom>, typename std::__fun<std::__logical_or, typename _Dom1::value_type>::result_type> std::operator||(const typename _Dom::value_type&, const _Expr<_Dom1, typename _Dom1::value_type>&)'
  416 |     _DEFINE_EXPR_BINARY_OPERATOR(||, struct std::__logical_or)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:416:5: note:   template argument deduction/substitution failed:
a.cc:89:34: note:   'std::set<long long int>' is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
   89 |     if(R.empty() || G.empty() || B || empty){
      |                                  ^
/usr/include/c++/14/bits/valarray_after.h:416:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__logical_or, std::_Expr, std::_ValArray, _Dom, typename _Dom::value_type>, typename std::__fun<std::__logical_or, typename _Dom1::value_type>::result_type> std::operator||(const _Expr<_Dom1, typename _Dom1::value_type>&, const valarray<typename _Dom::value_type>&)'
  416 |     _DEFINE_EXPR_BINARY_OPERATOR(||, struct std::__logical_or)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:416:5: note:   template argument deduction/substitution failed:
a.cc:89:34: note:   mismatched types 'const std::_Expr<_Dom1, typename _Dom1::value_type>' and 'bool'
   89 |     if(R.empty() || G.empty() || B || empty){
      |                                  ^
/usr/include/c++/14/bits/valarray_after.h:416:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__logical_or, std::_ValArray, std::_Expr, typename _Dom::value_type, _Dom>, typename std::__fun<std::__logical_or, typename _Dom1::value_type>::result_type> std::operator||(const valarray<typename _Dom::value_type>&, const _Expr<_Dom1, typename _Dom1::value_type>&)'
  416 |     _DEFINE_EXPR_BINARY_OPERATOR(||, struct std::__logical_or)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:416:5: note:   template argument deduction/substitution failed:
a.cc:89:34: note:   'std::set<long long int>' is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
   89 |     if(R.empty() || G.empty() || B || empty){
      |                                  ^
/usr/include/c++/14/valarray:1207:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__logical_or, std::_ValArray, std::_ValArray, _Tp, _Tp>, typename std::__fun<std::__logical_or, _Tp>::result_type> std::operator||(const valarray<_Tp>&, const valarray<_Tp>&)'
 1207 | _DEFINE_BINARY_OPERATOR(||, __logical_or)
      | ^~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/valarray:1207:1: note:   template argument deduction/substitution failed:
a.cc:89:34: note:   mismatched types 'const std::valarray<_Tp>' and 'bool'
   89 |     if(R.empty() || G.empty() || B || empty){
      |                                  ^
/usr/include/c++/14/valarray:1207:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__logical_or, std::_ValArray, std::_Constant, _Tp, _Tp>, typename std::__fun<std::__logical_or, _Tp>::result_type> std::operator||(const valarray<_Tp>&, const typename valarray<_Tp>::value_type&)'
 1207 | _DEFINE_BINARY_OPERATOR(||, __logical_or)
      | ^~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/valarray:1207:1: note:   template argument deduction/substitution failed:
a.cc:89:34: note:   mismatched types 'const std::valarray<_Tp>' and 'bool'
   89 |     if(R.empty() || G.empty() || B || empty){
      |                                  ^
/usr/include/c++/14/valarray:1207:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__logical_or, std::_Constant, std::_ValArray, _Tp, _Tp>, typename std::__fun<std::__logical_or, _Tp>::result_type> std::operator||(const typename valarray<_Tp>::value_type&, const valarray<_Tp>&)'
 1207 | _DEFINE_BINARY_OPERATOR(||, __logical_or)
      | ^~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/valarray:1207:1: note:   template argument deduction/substitution failed:
a.cc:89:34: note:   'std::set<long long int>' is not derived from 'const std::valarray<_Tp>'
   89 |     if(R.empty() || G.empty() || B || empty){
      |                                  ^