Language: C++

#include<iostream>
#include<cmath>
#include<algorithm>
#include<iomanip>
#include<string>
#include<vector>
#include<cstdio>
#include<cstring>
#include<map>
#include<set>
#include<fstream>
#include<sstream>
#include<queue>
#include<iterator>
#include<stack>

using namespace std;

#define st first
#define nd second
#define FOR(i,a,b) for(int i=a;i<b;i++)
#define REV(a) reverse(a.begin(),a.end())
#define SORT(a) sort(a.begin(),a.end())
#define inf (int)1e9
#define linf (long long)1e18

typedef long long ll;
typedef short int si;
typedef pair<int,int> pii;
typedef pair<ll,int> pli;
typedef vector<int> vi;
typedef vector<pii> vpii;
typedef vector<pli> vpli;

int n,a[100000],mx=0,mm;
ll ans=0;

int main() {
		cin>>n;
		FOR(i,0,n)cin>>a[i],mx=max(mx,a[i]),mm=min(mm,a[i]);
		sort(a,a+n);
		FOR(i,mm-1,mx+1){
				ans=max(ans,upper_bound(a,a+n,i+1)-lower_bound(a,a+n,i-1));
		}
		cout<<ans<<endl;




  return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:43:40: error: no matching function for call to 'max(ll&, long int)'
   43 |                                 ans=max(ans,upper_bound(a,a+n,i+1)-lower_bound(a,a+n,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:43:40: note:   deduced conflicting types for parameter 'const _Tp' ('long long int' and 'long int')
   43 |                                 ans=max(ans,upper_bound(a,a+n,i+1)-lower_bound(a,a+n,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:3:
/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:43:40: note:   mismatched types 'std::initializer_list<_Tp>' and 'long long int'
   43 |                                 ans=max(ans,upper_bound(a,a+n,i+1)-lower_bound(a,a+n,i-1));
      |                                     ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~