Language: C++

#include<bits/stdc++.h>
using namespace std;

int  main(){
  int W, H, N;
  cin >> W >> H >> N;
  vector<int> vec(3*N);
  for(int i = 0; i < 3*N; i++){
    cin >> vec[i];
  }
  
  vector<int> left(0);//1
  vector<int> right(0);//2
  vector<int> down(0);//3
  vector<int> up(0);//4
  
  int U = H;
  int D = 0;
  int L = 0;
  int R = W;
  for(int i = 0; i < N; i++){
    if(vec.at(3i + 2) == 1){
      left.push(vec[3i]);
    }
    else if(vec.at(3i + 2) == '2'){
      right.push(vec[3i]);
    }
    else if(vec[3i + 2] == '3'){
      down.push(vec[3i+1]);
    }
    else if(vec[3i + 2] == '4'){
      up.push(vec[3i+1]);
    }
  }
  
  
  int length = min_element(up.begin(), up.end()) = max_element(down.begin(), down.end());
  int wide = min_element(right.begin(), up.end()) = max_element(left.begin(), down.end());
  
  if(length < 0 || wide < 0){
    cout << 0 << endl;
  }
  else{
    cout << lenth*wide << endl;
  }
  

Compiler output:
a.cc: In function 'int main()':
a.cc:22:18: error: no match for 'operator+' (operand types are 'std::complex<double>' and 'int')
   22 |     if(vec.at(3i + 2) == 1){
      |               ~~ ^ ~
      |               |    |
      |               |    int
      |               std::complex<double>
In file included from /usr/include/c++/14/bits/stl_algobase.h:67,
                 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_iterator.h:627:5: note: candidate: 'template<class _Iterator> constexpr std::reverse_iterator<_Iterator> std::operator+(typename reverse_iterator<_Iterator>::difference_type, const reverse_iterator<_Iterator>&)'
  627 |     operator+(typename reverse_iterator<_Iterator>::difference_type __n,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:627:5: note:   template argument deduction/substitution failed:
a.cc:22:20: note:   mismatched types 'const std::reverse_iterator<_Iterator>' and 'int'
   22 |     if(vec.at(3i + 2) == 1){
      |                    ^
/usr/include/c++/14/bits/stl_iterator.h:1798:5: note: candidate: 'template<class _Iterator> constexpr std::move_iterator<_IteratorL> std::operator+(typename move_iterator<_IteratorL>::difference_type, const move_iterator<_IteratorL>&)'
 1798 |     operator+(typename move_iterator<_Iterator>::difference_type __n,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1798:5: note:   template argument deduction/substitution failed:
a.cc:22:20: note:   mismatched types 'const std::move_iterator<_IteratorL>' and 'int'
   22 |     if(vec.at(3i + 2) == 1){
      |                    ^
In file included from /usr/include/c++/14/string:54,
                 from /usr/include/c++/14/bitset:52,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:52:
/usr/include/c++/14/bits/basic_string.h:3598:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3598 |     operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3598:5: note:   template argument deduction/substitution failed:
a.cc:22:20: note:   'std::complex<double>' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   22 |     if(vec.at(3i + 2) == 1){
      |                    ^
/usr/include/c++/14/bits/basic_string.h:3616:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const _CharT*, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3616 |     operator+(const _CharT* __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3616:5: note:   template argument deduction/substitution failed:
a.cc:22:20: note:   mismatched types 'const _CharT*' and 'std::complex<double>'
   22 |     if(vec.at(3i + 2) == 1){
      |                    ^
/usr/include/c++/14/bits/basic_string.h:3635:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(_CharT, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3635 |     operator+(_CharT __lhs, const basic_string<_CharT,_Traits,_Alloc>& __rhs)
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3635:5: note:   template argument deduction/substitution failed:
a.cc:22:20: note:   mismatched types 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>' and 'int'
   22 |     if(vec.at(3i + 2) == 1){
      |                    ^
/usr/include/c++/14/bits/basic_string.h:3652:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, const _CharT*)'
 3652 |     operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3652:5: note:   template argument deduction/substitution failed:
a.cc:22:20: note:   'std::complex<double>' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   22 |     if(vec.at(3i + 2) == 1){
      |                    ^
/usr/include/c++/14/bits/basic_string.h:3670:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, _CharT)'
 3670 |     operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs, _CharT __rhs)
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3670:5: note:   template argument deduction/substitution failed:
a.cc:22:20: note:   'std::complex<double>' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   22 |     if(vec.at(3i + 2) == 1){
      |                    ^
/usr/include/c++/14/bits/basic_string.h:3682:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(__cxx11::basic_string<_CharT, _Traits, _Allocator>&&, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3682 |     operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3682:5: note:   template argument deduction/substitution failed:
a.cc:22:20: note:   'std::complex<double>' is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   22 |     if(vec.at(3i + 2) == 1){
      |                    ^
/usr/include/c++/14/bits/basic_string.h:3689:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, __cxx11::basic_string<_CharT, _Traits, _Allocator>&&)'
 3689 |     operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3689:5: note:   template argument deduction/substitution failed:
a.cc:22:20: note:   'std::complex<double>' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   22 |     if(vec.at(3i + 2) == 1){
      |                    ^
/usr/include/c++/14/bits/basic_string.h:3696:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(__cxx11::basic_string<_CharT, _Traits, _Allocator>&&, __cxx11::basic_string<_CharT, _Traits, _Allocator>&&)'
 3696 |     operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3696:5: note:   template argument deduction/substitution failed:
a.cc:22:20: note:   'std::complex<double>' is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   22 |     if(vec.at(3i + 2) == 1){
      |                    ^
/usr/include/c++/14/bits/basic_string.h:3719:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const _CharT*, __cxx11::basic_string<_CharT, _Traits, _Allocator>&&)'
 3719 |     operator+(const _CharT* __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3719:5: note:   template argument deduction/substitution failed:
a.cc:22:20: note:   mismatched types 'const _CharT*' and 'std::complex<double>'
   22 |     if(vec.at(3i + 2) == 1){
      |                    ^
/usr/include/c++/14/bits/basic_string.h:3726:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(_CharT, __cxx11::basic_string<_CharT, _Traits, _Allocator>&&)'
 3726 |     operator+(_CharT __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3726:5: note:   template argument deduction/substitution failed:
a.cc:22:20: note:   mismatched types 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>' and 'int'
   22 |     if(vec.at(3i + 2) == 1){
      |                    ^
/usr/include/c++/14/bits/basic_string.h:3733:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(__cxx11::basic_string<_CharT, _Traits, _Allocator>&&, const _CharT*)'
 3733 |     operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3733:5: note:   template argument deduction/substitution failed:
a.cc:22:20: note:   'std::complex<double>' is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   22 |     if(vec.at(3i + 2) == 1){
      |                    ^
/usr/include/c++/14/bits/basic_string.h:3740:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(__cxx11::basic_string<_CharT, _Traits, _Allocator>&&, _CharT)'
 3740 |     operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3740:5: note:   template argument deduction/substitution failed:
a.cc:22:20: note:   'std::complex<double>' is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   22 |     if(vec.at(3i + 2) == 1){
      |                    ^
In file included from /usr/include/c++/14/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:127:
/usr/include/c++/14/complex:340:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::operator+(const complex<_Tp>&, const complex<_Tp>&)'
  340 |     operator+(const complex<_Tp>& __x, const complex<_Tp>& __y)
      |     ^~~~~~~~
/usr/include/c++/14/complex:340:5: note:   template argument deduction/substitution failed:
a.cc:22:20: note:   mismatched types 'const std::complex<_Tp>' and 'int'
   22 |     if(vec.at(3i + 2) == 1){
      |