Language: C++

#include "iostream"
#include "climits"
#include "list"
#include "queue"
#include "stack"
#include "set"
#include "functional"
#include "algorithm"
#include "string"
#include "map"
#include "iomanip"
#include "random"

using namespace std;

const long long int MOD = 1000000007;
const long double EPS = 0.00000001;
const long double PI = 3.1415926535897932384626433;

long long int N, M, K, H, W, L, R;

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);

	cin >> H >> W >> N;
	vector<pair<int, int>>box;
	for (int i = 0; i < N; i++) {
		int sx, sy, gx, gy;
		cin >> sy >> sx >> gy >> gx;
		if (sx != 0 && sx != W&&sy!=0&&sy!=H) {
			continue;
		}
		if (gx != 0 && gx != W&&gy!=0&&gy!=H) {
			continue;
		}
		if (sy == 0) {
			box.push_back({ sx,i });
		}
		else if (sx == W) {
			box.push_back({ W + sy,i });
		}
		else if (sy == H) {
			box.push_back({ 2 * W + H - sx,i });
		}
		else {
			box.push_back({ 2 * W + 2 * H - sy,i });
		}
		if (gy == 0) {
			box.push_back({ gx,i });
		}
		else if (gx == W) {
			box.push_back({ W + gy,i });
		}
		else if (gy == H) {
			box.push_back({ 2 * W + H - gx,i });
		}
		else {
			box.push_back({ 2 * W + 2 * H - gy,i });
		}
	}
	if (box.empty()) {
		cout << "YES\n";
		return 0;
	}
	sort(box.begin(), box.end());
	M = box.size();
	list<pair<int, int>>bag(box.begin(), box.end());
	list<pair<int, int>>::iterator l=bag.end;
	list<pair<int, int>>::iterator r=bag.end;
	for (auto i = bag.begin(); i != bag.end(); i++) {
		auto j = i;
		j++;
		if (j == bag.end) {
			j = bag.begin();
		}
		if ((*i).second == (*j).second) {
			l = i;
			r = j;
			break;
		}
	}
	if (l == bag.end) {
		cout << "NO\n";
		return;
	}
	while (!bag.empty()) {
		if ((*l).second == (*r).second) {
			auto rx = r;
			auto lx = l;
			if (lx == bag.begin()) {
				lx = bag.end;
			}
			lx--;
			rx++;
			if (rx == bag.end) {
				rx = bag.begin;
			}
			bag.erase(l);
			bag.erase(r);
			r = rx;
			l = lx;
			continue;
		}
		auto rn = r;
		rn++;
		if (rn == bag.end) {
			rn = bag.begin;
		}
		auto ln = l;
		if (ln == bag.begin) {
			ln = bag.end;
		}
		ln--;
		if ((*l).second == (*ln).second) {
			auto lx = ln;
			if (lx == bag.begin) {
				lx = bag.end;
			}
			lx--;
			bag.erase(l);
			bag.erase(ln);
			l = lx;
			continue;
		}
		if ((*r).second == (*rn).second) {
			auto rx = rn;
			rx++;
			if (rx == bag.end) {
				rx = bag.begin;
			}
			bag.erase(r);
			bag.erase(rn);
			l = rx;
			continue;
		}
		l = bag.end;
		r = bag.end;
		for (auto i = bag.begin(); i != bag.end(); i++) {
			auto j = i;
			j++;
			if (j == bag.end) {
				j = bag.begin();
			}
			if ((*i).second == (*j).second) {
				l = i;
				r = j;
				break;
			}
		}
		if (l == bag.end) {
			cout << "NO\n";
			return;
		}
	}
	cout << "YES\n";
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:69:46: error: conversion from '<unresolved overloaded function type>' to non-scalar type 'std::__cxx11::list<std::pair<int, int> >::iterator' requested
   69 |         list<pair<int, int>>::iterator l=bag.end;
      |                                          ~~~~^~~
a.cc:70:46: error: conversion from '<unresolved overloaded function type>' to non-scalar type 'std::__cxx11::list<std::pair<int, int> >::iterator' requested
   70 |         list<pair<int, int>>::iterator r=bag.end;
      |                                          ~~~~^~~
a.cc:74:23: error: no match for 'operator==' (operand types are 'std::_List_iterator<std::pair<int, int> >' and '<unresolved overloaded function type>')
   74 |                 if (j == bag.end) {
      |                     ~ ^~ ~~~~~~~
      |                     |        |
      |                     |        <unresolved overloaded function type>
      |                     std::_List_iterator<std::pair<int, int> >
In file included from /usr/include/c++/14/iosfwd:42,
                 from /usr/include/c++/14/ios:40,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41,
                 from a.cc:1:
/usr/include/c++/14/bits/postypes.h:192:5: note: candidate: 'template<class _StateT> bool std::operator==(const fpos<_StateT>&, const fpos<_StateT>&)'
  192 |     operator==(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
      |     ^~~~~~~~
/usr/include/c++/14/bits/postypes.h:192:5: note:   template argument deduction/substitution failed:
a.cc:74:30: note:   'std::_List_iterator<std::pair<int, int> >' is not derived from 'const std::fpos<_StateT>'
   74 |                 if (j == bag.end) {
      |                              ^~~
In file included from /usr/include/c++/14/string:43,
                 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:
/usr/include/c++/14/bits/allocator.h:235:5: note: candidate: 'template<class _T1, class _T2> bool std::operator==(const allocator<_CharT>&, const allocator<_T2>&)'
  235 |     operator==(const allocator<_T1>&, const allocator<_T2>&)
      |     ^~~~~~~~
/usr/include/c++/14/bits/allocator.h:235:5: note:   template argument deduction/substitution failed:
a.cc:74:30: note:   'std::_List_iterator<std::pair<int, int> >' is not derived from 'const std::allocator<_CharT>'
   74 |                 if (j == bag.end) {
      |                              ^~~
In file included from /usr/include/c++/14/string:48:
/usr/include/c++/14/bits/stl_iterator.h:441:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator==(const reverse_iterator<_Iterator>&, const reverse_iterator<_Iterator>&)'
  441 |     operator==(const reverse_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:441:5: note:   template argument deduction/substitution failed:
a.cc:74:30: note:   'std::_List_iterator<std::pair<int, int> >' is not derived from 'const std::reverse_iterator<_Iterator>'
   74 |                 if (j == bag.end) {
      |                              ^~~
/usr/include/c++/14/bits/stl_iterator.h:486:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator==(const reverse_iterator<_Iterator>&, const reverse_iterator<_IteratorR>&)'
  486 |     operator==(const reverse_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:486:5: note:   template argument deduction/substitution failed:
a.cc:74:30: note:   'std::_List_iterator<std::pair<int, int> >' is not derived from 'const std::reverse_iterator<_Iterator>'
   74 |                 if (j == bag.end) {
      |                              ^~~
/usr/include/c++/14/bits/stl_iterator.h:1667:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator==(const move_iterator<_IteratorL>&, const move_iterator<_IteratorR>&)'
 1667 |     operator==(const move_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1667:5: note:   template argument deduction/substitution failed:
a.cc:74:30: note:   'std::_List_iterator<std::pair<int, int> >' is not derived from 'const std::move_iterator<_IteratorL>'
   74 |                 if (j == bag.end) {
      |                              ^~~
/usr/include/c++/14/bits/stl_iterator.h:1737:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator==(const move_iterator<_IteratorL>&, const move_iterator<_IteratorL>&)'
 1737 |     operator==(const move_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1737:5: note:   template argument deduction/substitution failed:
a.cc:74:30: note:   'std::_List_iterator<std::pair<int, int> >' is not derived from 'const std::move_iterator<_IteratorL>'
   74 |                 if (j == bag.end) {
      |                              ^~~
In file included from /usr/include/c++/14/bits/stl_algobase.h:64,
                 from /usr/include/c++/14/string:51:
/usr/include/c++/14/bits/stl_pair.h:1033:5: note: candidate: 'template<class _T1, class _T2> constexpr bool std::operator==(const pair<_T1, _T2>&, const pair<_T1, _T2>&)'
 1033 |     operator==(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_pair.h:1033:5: note:   template argument deduction/substitution failed:
a.cc:74:30: note:   'std::_List_iterator<std::pair<int, int> >' is not derived from 'const std::pair<_T1, _T2>'
   74 |                 if (j == bag.end) {
      |                              ^~~
In file included from /usr/include/c++/14/bits/basic_string.h:47,
                 from /usr/include/c++/14/string:54:
/usr/include/c++/14/string_view:629:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator==(basic_string_view<_CharT, _Traits>, __type_identity_t<basic_string_view<_CharT, _Traits> >)'
  629 |     operator==(basic_string_view<_CharT, _Traits> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:629:5: note:   template argument deduction/substitution failed:
a.cc:74:30: note:   'std::_List_iterator<std::pair<int, int> >' is not derived from 'std::basic_string_view<_CharT, _Traits>'
   74 |                 if (j == bag.end) {
      |                              ^~~
/usr/include/c++/14/string_view:637:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator==(basic_string_view<_CharT, _Traits>, basic_string_view<_CharT, _Traits>)'
  637 |     operator==(basic_string_view<_CharT, _Traits> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:637:5: note:   template argument deduction/substitution failed:
a.cc:74:30: note:   'std::_List_iterator<std::pair<int, int> >' is not derived from 'std::basic_string_view<_CharT, _Traits>'
   74 |                 if (j == bag.end) {
      |                              ^~~
/usr/include/c++/14/string_view:644:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator==(__type_identity_t<basic_string_view<_CharT, _Traits> >, basic_string_view<_CharT, _Traits>)'
  644 |     operator==(__type_identity_t<basic_string_view<_CharT, _Traits>> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:644:5: note:   template argument deduction/substitution failed:
a.cc:74:30: note:   mismatched types 'std::basic_string_view<_CharT, _Traits>' and 'std::__cxx11::list<std::pair<int, int> >::const_iterator (std::__cxx11::list<std::pair<int, int> >::*)() const noexcept'
   74 |                 if (j == bag.end) {
      |                              ^~~
a.cc:74:30: note:   mismatched types 'std::basic_string_view<_CharT, _Traits>' and 'std::__cxx11::list<std::pair<int, int> >::iterator (std::__cxx11::list<std::pair<int, int> >::*)() noexcept'
a.cc:74:30: note:   couldn't deduce template parameter '_CharT'
/usr/include/c++/14/bits/basic_string.h:3755:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3755 |     operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3755:5: note:   template argument deduction/substitution failed:
a.cc:74:30: note:   'std::_List_iterator<std::pair<int, int> >' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   74 |                 if (j == bag.end) {
      |                              ^~~
/usr/include/c++/14/bits/basic_string.h:3772:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, const _CharT*)'
 3772 |     operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3772:5: note:   template argument deduction/substitution failed:
a.cc:74:30: note:   'std::_List_iterator<std::pair<int, int> >' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   74 |                 if (j == bag.end) {
      |                              ^~~
/usr/include/c++/14/bits/basic_string.h:3819:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const _CharT*, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3819 |     operator==(const _CharT* __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3819:5: note:   template argument deduction/substitution failed:
a.cc:74:30: note:   mismatched types 'const _CharT*' and 'std::_List_iterator<std::pair<int, int> >'
   74 |                 if (j == bag.end) {
      |                              ^~~
In file included from /usr/include/c++/14/bits/memory_resource.h:47,
                 from /usr/include/c++/14/string:68:
/usr/include/c++/14/tuple:2558:5: note: candidate: 'template<class ... _TElements, class ... _UElements> constexpr bool std::operator==(const tuple<_UTypes ...>&, const tuple<_Elements ...>&)'
 2558 |     operato