Language: C++

#pragma GCC optimize("Ofast",3,"inline")
#include<bits/stdc++.h>
using namespace std;
#define fir first
#define sec second
#define m_p make_pair
#define y1 ygftgfgcdtfgxffgx
#define y2 yfdsesgvtyghftfvv
#define x1 xvyr6cf6fgcfgf676
#define x2 xcr6rfc5r66y6r6fr
#define up_bound upper_bound
#define low_bound lower_bound
#define next_per next_permutation
#define pb push_back
#define i_to_s to_string
typedef priority_queue<int> p_queue;
typedef priority_queue<int, vector<int>, greater<int> > min_p_queue;
typedef long long ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
int mon[20]={31,28,31,30,31,30,31,31,30,31,30,31};
ll gcd(ll x,ll y){return ((y==0)?x:gcd(y,x%y));}
int n,a[100050];
const int INF=1e5+7;
ll res,x;
int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(0);
//	freopen(".in","r",stdin);
//	freopen(".out","w",stdout);
	for(int i=0;i<n;i++)cin>>x,a[x]++;
	res=a[0]+a[1];
	for(int i=1;i<INF;i++)res=max(res,a[i-1]+a[i]+a[i+1]);
	cout<<res;
	return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:34:38: error: no matching function for call to 'max(ll&, int)'
   34 |         for(int i=1;i<INF;i++)res=max(res,a[i-1]+a[i]+a[i+1]);
      |                                   ~~~^~~~~~~~~~~~~~~~~~~~~~~~
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:2:
/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:34:38: note:   deduced conflicting types for parameter 'const _Tp' ('long long int' and 'int')
   34 |         for(int i=1;i<INF;i++)res=max(res,a[i-1]+a[i]+a[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:
/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:34:38: note:   mismatched types 'std::initializer_list<_Tp>' and 'long long int'
   34 |         for(int i=1;i<INF;i++)res=max(res,a[i-1]+a[i]+a[i+1]);
      |                                   ~~~^~~~~~~~~~~~~~~~~~~~~~~~