Language: C++

#include<bits/stdc++.h>
using namespace std;
#define MOD 1000000007
#define INF (1<<29)
#define LINF (1LL<<60)
#define EPS (1e-10)
#define PI 3.1415926535897932384626433832795028
#define all(a) (a).begin(),(a).end()
#define sz(x) (int)x.size()
#define max_heap priority_queue<int>
#define min_heap priority_queue<int,vector<int>,greater<int>>
using ll = long long;
#define int long long
#define endl "\n"
#define vi vector<int>
#define pb push_back
#define inp_arr(a,n) for(ll i=0;i<n;i++)cin>>a[i];
#define out_arr(a) for(ll i=0;i<a.size();i++)cout<<a[i]<<" ";
#define deb(n) cerr << #n << " = " << n << "\n";
int gcd(int a, int b) { if (a == 0) return b; return gcd(b % a, a);}
ll mypower(ll x,ll n,ll c){
    if(n == 0)
        return 1;
    ll temp = mypower(x,n/2,c)%c;
    if(n%2)
        return (n<0)? (1/x)*temp*temp%c: ((x*temp)%c)*temp%c;
    else
        return temp*temp%c;
}
bool codejam = 0;

int32_t main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
	#ifndef ONLINE_JUDGE
		freopen("input.txt","r",stdin);
		freopen("output.txt","w",stdout);
	#endif

	vector<int> a(2);
	vector<int> b(2);
	cin>>a[0]>>a[1]>>b[0]>>b[1];
	int ans = -1e9;
	for(int i=0;i<2;i++){
		for(int j=0;j<2;j++)
			ans = max(ans,a[i]*b[j]);
	}
	if(a[1]<0 and b[0]>0)
		ans = max(ans,0);
	if(b[1]<0 and a[0]>0)
		ans = max(ans,0);
	cout<<ans<<endl;
	return 0;
}


Compiler output:
a.cc: In function 'int32_t main()':
a.cc:50:26: error: no matching function for call to 'max(long long int&, int)'
   50 |                 ans = max(ans,0);
      |                       ~~~^~~~~~~
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:50:26: note:   deduced conflicting types for parameter 'const _Tp' ('long long int' and 'int')
   50 |                 ans = max(ans,0);
      |                       ~~~^~~~~~~
/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:50:26: note:   mismatched types 'std::initializer_list<_Tp>' and 'long long int'
   50 |                 ans = max(ans,0);
      |                       ~~~^~~~~~~
a.cc:52:26: error: no matching function for call to 'max(long long int&, int)'
   52 |                 ans = max(ans,0);
      |                       ~~~^~~~~~~
/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:52:26: note:   deduced conflicting types for parameter 'const _Tp' ('long long int' and 'int')
   52 |                 ans = max(ans,0);
      |                       ~~~^~~~~~~
/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
/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:52:26: note:   mismatched types 'std::initializer_list<_Tp>' and 'long long int'
   52 |                 ans = max(ans,0);
      |                       ~~~^~~~~~~