Language: C++

#include<bits/stdc++.h>
using namespace std;
#define pb push_back
#define mp make_pair
#define F first
#define S second
typedef long long ll;
typedef pair<int, int> pii;
#define sz(x) (int)(x).size()
#define all(x) x.begin(), x.end()
 
ll powmod(ll a,ll b) {ll res=1; assert(b>=0); for(;b;b>>=1){if(b&1)res=res*a;a=a*a;}return res;}
ll gcd(ll a,ll b) { return b?gcd(b,a%b):a;}

int main(){
  ios_base::sync_with_stdio(false); cin.tie(NULL); 
  ll n,a;
  cin>>n;
  vector<ll> ans = 1;
  int flag = 0;
  for(int i=0;i<n;++i){ cin>>a; ll tans = a*ans; if(tans<ans && a!=0){flag = 1; break;} ans=tans; }
  if(flag) cout<<"-1\n";
  else cout<<ans<<'\n';
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:19:20: error: conversion from 'int' to non-scalar type 'std::vector<long long int>' requested
   19 |   vector<ll> ans = 1;
      |                    ^
a.cc:21:44: error: no match for 'operator*' (operand types are 'll' {aka 'long long int'} and 'std::vector<long long int>')
   21 |   for(int i=0;i<n;++i){ cin>>a; ll tans = a*ans; if(tans<ans && a!=0){flag = 1; break;} ans=tans; }
      |                                           ~^~~~
      |                                           | |
      |                                           | std::vector<long long int>
      |                                           ll {aka long long int}
In file included from /usr/include/c++/14/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:127,
                 from a.cc:1:
/usr/include/c++/14/complex:400:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::operator*(const complex<_Tp>&, const complex<_Tp>&)'
  400 |     operator*(const complex<_Tp>& __x, const complex<_Tp>& __y)
      |     ^~~~~~~~
/usr/include/c++/14/complex:400:5: note:   template argument deduction/substitution failed:
a.cc:21:45: note:   mismatched types 'const std::complex<_Tp>' and 'll' {aka 'long long int'}
   21 |   for(int i=0;i<n;++i){ cin>>a; ll tans = a*ans; if(tans<ans && a!=0){flag = 1; break;} ans=tans; }
      |                                             ^~~
/usr/include/c++/14/complex:409:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::operator*(const complex<_Tp>&, const _Tp&)'
  409 |     operator*(const complex<_Tp>& __x, const _Tp& __y)
      |     ^~~~~~~~
/usr/include/c++/14/complex:409:5: note:   template argument deduction/substitution failed:
a.cc:21:45: note:   mismatched types 'const std::complex<_Tp>' and 'll' {aka 'long long int'}
   21 |   for(int i=0;i<n;++i){ cin>>a; ll tans = a*ans; if(tans<ans && a!=0){flag = 1; break;} ans=tans; }
      |                                             ^~~
/usr/include/c++/14/complex:418:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::operator*(const _Tp&, const complex<_Tp>&)'
  418 |     operator*(const _Tp& __x, const complex<_Tp>& __y)
      |     ^~~~~~~~
/usr/include/c++/14/complex:418:5: note:   template argument deduction/substitution failed:
a.cc:21:45: note:   'std::vector<long long int>' is not derived from 'const std::complex<_Tp>'
   21 |   for(int i=0;i<n;++i){ cin>>a; ll tans = a*ans; if(tans<ans && a!=0){flag = 1; break;} ans=tans; }
      |                                             ^~~
In file included from /usr/include/c++/14/valarray:605,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:166:
/usr/include/c++/14/bits/valarray_after.h:407:5: note: candidate: 'template<class _Dom1, class _Dom2> std::_Expr<std::__detail::_BinClos<std::__multiplies, std::_Expr, std::_Expr, _Dom1, _Dom2>, typename std::__fun<std::__multiplies, typename _Dom1::value_type>::result_type> std::operator*(const _Expr<_Dom1, typename _Dom1::value_type>&, const _Expr<_Dom2, typename _Dom2::value_type>&)'
  407 |     _DEFINE_EXPR_BINARY_OPERATOR(*, struct std::__multiplies)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:407:5: note:   template argument deduction/substitution failed:
a.cc:21:45: note:   mismatched types 'const std::_Expr<_Dom1, typename _Dom1::value_type>' and 'll' {aka 'long long int'}
   21 |   for(int i=0;i<n;++i){ cin>>a; ll tans = a*ans; if(tans<ans && a!=0){flag = 1; break;} ans=tans; }
      |                                             ^~~
/usr/include/c++/14/bits/valarray_after.h:407:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__multiplies, std::_Expr, std::_Constant, _Dom, typename _Dom::value_type>, typename std::__fun<std::__multiplies, typename _Dom1::value_type>::result_type> std::operator*(const _Expr<_Dom1, typename _Dom1::value_type>&, const typename _Dom::value_type&)'
  407 |     _DEFINE_EXPR_BINARY_OPERATOR(*, struct std::__multiplies)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:407:5: note:   template argument deduction/substitution failed:
a.cc:21:45: note:   mismatched types 'const std::_Expr<_Dom1, typename _Dom1::value_type>' and 'll' {aka 'long long int'}
   21 |   for(int i=0;i<n;++i){ cin>>a; ll tans = a*ans; if(tans<ans && a!=0){flag = 1; break;} ans=tans; }
      |                                             ^~~
/usr/include/c++/14/bits/valarray_after.h:407:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__multiplies, std::_Constant, std::_Expr, typename _Dom::value_type, _Dom>, typename std::__fun<std::__multiplies, typename _Dom1::value_type>::result_type> std::operator*(const typename _Dom::value_type&, const _Expr<_Dom1, typename _Dom1::value_type>&)'
  407 |     _DEFINE_EXPR_BINARY_OPERATOR(*, struct std::__multiplies)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:407:5: note:   template argument deduction/substitution failed:
a.cc:21:45: note:   'std::vector<long long int>' is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
   21 |   for(int i=0;i<n;++i){ cin>>a; ll tans = a*ans; if(tans<ans && a!=0){flag = 1; break;} ans=tans; }
      |                                             ^~~
/usr/include/c++/14/bits/valarray_after.h:407:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__multiplies, std::_Expr, std::_ValArray, _Dom, typename _Dom::value_type>, typename std::__fun<std::__multiplies, typename _Dom1::value_type>::result_type> std::operator*(const _Expr<_Dom1, typename _Dom1::value_type>&, const valarray<typename _Dom::value_type>&)'
  407 |     _DEFINE_EXPR_BINARY_OPERATOR(*, struct std::__multiplies)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:407:5: note:   template argument deduction/substitution failed:
a.cc:21:45: note:   mismatched types 'const std::_Expr<_Dom1, typename _Dom1::value_type>' and 'll' {aka 'long long int'}
   21 |   for(int i=0;i<n;++i){ cin>>a; ll tans = a*ans; if(tans<ans && a!=0){flag = 1; break;} ans=tans; }
      |                                             ^~~
/usr/include/c++/14/bits/valarray_after.h:407:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__multiplies, std::_ValArray, std::_Expr, typename _Dom::value_type, _Dom>, typename std::__fun<std::__multiplies, typename _Dom1::value_type>::result_type> std::operator*(const valarray<typename _Dom::value_type>&, const _Expr<_Dom1, typename _Dom1::value_type>&)'
  407 |     _DEFINE_EXPR_BINARY_OPERATOR(*, struct std::__multiplies)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:407:5: note:   template argument deduction/substitution failed:
a.cc:21:45: note:   'std::vector<long long int>' is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
   21 |   for(int i=0;i<n;++i){ cin>>a; ll tans = a*ans; if(tans<ans && a!=0){flag = 1; break;} ans=tans; }
      |                                             ^~~
/usr/include/c++/14/valarray:1198:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__multiplies, std::_ValArray, std::_ValArray, _Tp, _Tp>, typename std::__fun<std::__multiplies, _Tp>::result_type> std::operator*(const valarray<_Tp>&, const valarray<_Tp>&)'
 1198 | _DEFINE_BINARY_OPERATOR(*, __multiplies)
      | ^~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/valarray:1198:1: note:   template argument deduction/substitution failed:
a.cc:21:45: note:   mismatched types 'const std::valarray<_Tp>' and 'll' {aka 'long long int'}
   21 |   for(int i=0;i<n;++i){ cin>>a; ll tans = a*ans; if(tans<ans && a!=0){flag = 1; break;} ans=tans; }
      |                                             ^~~
/usr/include/c++/14/valarray:1198:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__multiplies, std::_ValArray, std::_Constant, _Tp, _Tp>, typename std::__fun<std::__multiplies, _Tp>::result_type> std::operator*(const valarray<_Tp>&, const typename valarray<_Tp>::value_type&)'
 1198 | _DEFINE_BINARY_OPERATOR(*, __multiplies)
      | ^~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/valarray:1198:1: note:   template argument deduction/substitution failed:
a.cc:21:45: note:   mismatched types 'const std::valarray<_Tp>' and 'll' {aka 'long long int'}
   21 |   for(int i=0;i<n;++i){ cin>>a; ll tans = a*ans; if(tans<ans && a!=0){flag = 1; break;} ans=tans; }
      |                                             ^~~
/usr/include/c++/14/valarray:1198:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__multiplies, std::_Constant, std::_ValArray, _Tp, _Tp>, typename std::__fun<std::__multiplies, _Tp>::result_type> std::operator*(const typename valarray<_Tp>::value_type&, const valarray<_Tp>&)'
 1198 | _DEFINE_BINARY_OPERATOR(*, __multiplies)
      | ^~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/valarray:1198:1: note:   template argument deduction/substitution failed:
a.cc:21:45: note:   'std::vector<long long int>' is not derived from 'const std::valarray<_Tp>'
   21 |   for(int i=0;i<n;++i){ cin>>a; ll tans = a*ans; if(tans<ans && a!=0){flag = 1; break;} ans=tans; }
      |                                             ^~~
a.cc:21:57: error: no match for 'operator<' (operand types are 'll' {aka 'long long int'} and 'std::vector<long long int>')
   21 |   for(int i=0;i<n;++i){ cin>>a; ll tans = a*ans; if(tans<ans && a!=0){flag = 1; break;} ans=tans; }
      |                                                     ~~~~^~~~
      |                                                     |    |
      |                                                     |    std::vector<long long int>
      |                                                     ll {aka long long int}
In file included from /usr/include/c++/14/regex:68,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:181:
/usr/include/c++/14/bits/regex.h:1143:5: note: candidate: 'template<class _BiIter> bool std::__cxx11::operator<(const sub_match<_BiIter>&, const sub_match<_BiIter>&)'