Language: C++

#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <bitset>
#include <math.h>
#include <iomanip>
#include <queue>
#define inp(X) cin >> X
#define out(X) cout << X << endl
#define rep(i,n) for(int i=0;i<n;i++ )
#define rep2(i,f,n) for(int i=f;i<n;i++ )
#define MAX(A) *max_element(A.begin(),A.end())
#define MIN(A) *min_element(A.begin(),A.end())
#define SORT(A) sort(A.begin(),A.end())
using namespace std;

typedef long long int ll;
#define MOD 1000000007
#define INF 1000000001

ll gcd(ll x, ll y){
	if(y==0) return x;
	return gcd(y,x%y);
}

bool bfs(vector<vector<int>> g, vector<int> &dist, int sv)
{
	queue<int> q;
	q.push(sv);
	dist[sv]=0;
	while(!q.empty()){
		int now = q.front(); q.pop();
		for(auto v : g[now]){
			if(dist[v]!=-1) continue;
			dist[v] = dist[now]+1;
			q.push(v);
		}
	}
}

int main(void) {
	ll l,r; cin >> l >> r;
	ll mx = min(l+2019,r);
	ll ans = 2019;
	rep2(i,l,mx)rep2(j,i+1,mx+1){
		ans = min(ans,(i*j)%2019);
	}
	out(ans);
}




Compiler output:
a.cc: In function 'bool bfs(std::vector<std::vector<int> >, std::vector<int>&, int)':
a.cc:40:1: warning: no return statement in function returning non-void [-Wreturn-type]
   40 | }
      | ^
a.cc: In function 'int main()':
a.cc:47:26: error: no matching function for call to 'min(ll&, int)'
   47 |                 ans = min(ans,(i*j)%2019);
      |                       ~~~^~~~~~~~~~~~~~~~
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:233:5: note: candidate: 'template<class _Tp> constexpr const _Tp& std::min(const _Tp&, const _Tp&)'
  233 |     min(const _Tp& __a, const _Tp& __b)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:233:5: note:   template argument deduction/substitution failed:
a.cc:47:26: note:   deduced conflicting types for parameter 'const _Tp' ('long long int' and 'int')
   47 |                 ans = min(ans,(i*j)%2019);
      |                       ~~~^~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algobase.h:281:5: note: candidate: 'template<class _Tp, class _Compare> constexpr const _Tp& std::min(const _Tp&, const _Tp&, _Compare)'
  281 |     min(const _Tp& __a, const _Tp& __b, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:281:5: note:   candidate expects 3 arguments, 2 provided
In file included from /usr/include/c++/14/algorithm:61,
                 from a.cc:4:
/usr/include/c++/14/bits/stl_algo.h:5686:5: note: candidate: 'template<class _Tp> constexpr _Tp std::min(initializer_list<_Tp>)'
 5686 |     min(initializer_list<_Tp> __l)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5686:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_algo.h:5696:5: note: candidate: 'template<class _Tp, class _Compare> constexpr _Tp std::min(initializer_list<_Tp>, _Compare)'
 5696 |     min(initializer_list<_Tp> __l, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5696:5: note:   template argument deduction/substitution failed:
a.cc:47:26: note:   mismatched types 'std::initializer_list<_Tp>' and 'long long int'
   47 |                 ans = min(ans,(i*j)%2019);
      |                       ~~~^~~~~~~~~~~~~~~~