Language: C++

#include <iostream>
#include <string>
#include <stack>
#include <list>

using namespace std;

int main() {
	string area;
	cin >> area;

	int len = area.size(), sum = 0;

	stack<int> st1;
	list<pair<int, int> > lst;

	for (int i = 0; i < len; i++) {
		if (area[i] == '\\') {
			st1.push(i);
		}
		else if (area[i] == '/' && !st1.empty()) {
			int j = st1.top();
			st1.pop();

			sum += (i - j);

			int temp = i - j;
			while (!lst.empty() && lst.front().second > j) {
				temp += lst.front().first;
				lst.pop_front();
			}
			lst.push_front(make_pair(temp, j));
		}
	}

	cout << sum << endl;
	cout << lst.size() << " ";
	for (list<pair<int, int> >::iterator it = lst.rbegin(); it != lst.rend(); it++) {
		cout << (*it).first << " ";
	}
	cout << endl;

	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:38:61: error: conversion from 'std::__cxx11::list<std::pair<int, int> >::reverse_iterator' {aka 'std::reverse_iterator<std::_List_iterator<std::pair<int, int> > >'} to non-scalar type 'std::__cxx11::list<std::pair<int, int> >::iterator' requested
   38 |         for (list<pair<int, int> >::iterator it = lst.rbegin(); it != lst.rend(); it++) {
      |                                                   ~~~~~~~~~~^~
a.cc:38:68: error: no match for 'operator!=' (operand types are 'std::__cxx11::list<std::pair<int, int> >::iterator' and 'std::__cxx11::list<std::pair<int, int> >::reverse_iterator' {aka 'std::reverse_iterator<std::_List_iterator<std::pair<int, int> > >'})
   38 |         for (list<pair<int, int> >::iterator it = lst.rbegin(); it != lst.rend(); it++) {
      |                                                                 ~~ ^~ ~~~~~~~~~~
      |                                                                 |             |
      |                                                                 |             std::__cxx11::list<std::pair<int, int> >::reverse_iterator {aka std::reverse_iterator<std::_List_iterator<std::pair<int, int> > >}
      |                                                                 std::__cxx11::list<std::pair<int, int> >::iterator
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:197:5: note: candidate: 'template<class _StateT> bool std::operator!=(const fpos<_StateT>&, const fpos<_StateT>&)'
  197 |     operator!=(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
      |     ^~~~~~~~
/usr/include/c++/14/bits/postypes.h:197:5: note:   template argument deduction/substitution failed:
a.cc:38:80: note:   'std::__cxx11::list<std::pair<int, int> >::iterator' is not derived from 'const std::fpos<_StateT>'
   38 |         for (list<pair<int, int> >::iterator it = lst.rbegin(); it != lst.rend(); it++) {
      |                                                                                ^
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:243:5: note: candidate: 'template<class _T1, class _T2> bool std::operator!=(const allocator<_CharT>&, const allocator<_T2>&)'
  243 |     operator!=(const allocator<_T1>&, const allocator<_T2>&)
      |     ^~~~~~~~
/usr/include/c++/14/bits/allocator.h:243:5: note:   template argument deduction/substitution failed:
a.cc:38:80: note:   'std::__cxx11::list<std::pair<int, int> >::iterator' is not derived from 'const std::allocator<_CharT>'
   38 |         for (list<pair<int, int> >::iterator it = lst.rbegin(); it != lst.rend(); it++) {
      |                                                                                ^
In file included from /usr/include/c++/14/string:48:
/usr/include/c++/14/bits/stl_iterator.h:455:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator!=(const reverse_iterator<_Iterator>&, const reverse_iterator<_Iterator>&)'
  455 |     operator!=(const reverse_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:455:5: note:   template argument deduction/substitution failed:
a.cc:38:80: note:   'std::__cxx11::list<std::pair<int, int> >::iterator' is not derived from 'const std::reverse_iterator<_Iterator>'
   38 |         for (list<pair<int, int> >::iterator it = lst.rbegin(); it != lst.rend(); it++) {
      |                                                                                ^
/usr/include/c++/14/bits/stl_iterator.h:500:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator!=(const reverse_iterator<_Iterator>&, const reverse_iterator<_IteratorR>&)'
  500 |     operator!=(const reverse_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:500:5: note:   template argument deduction/substitution failed:
a.cc:38:80: note:   'std::__cxx11::list<std::pair<int, int> >::iterator' is not derived from 'const std::reverse_iterator<_Iterator>'
   38 |         for (list<pair<int, int> >::iterator it = lst.rbegin(); it != lst.rend(); it++) {
      |                                                                                ^
/usr/include/c++/14/bits/stl_iterator.h:1686:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator!=(const move_iterator<_IteratorL>&, const move_iterator<_IteratorR>&)'
 1686 |     operator!=(const move_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1686:5: note:   template argument deduction/substitution failed:
a.cc:38:80: note:   'std::__cxx11::list<std::pair<int, int> >::iterator' is not derived from 'const std::move_iterator<_IteratorL>'
   38 |         for (list<pair<int, int> >::iterator it = lst.rbegin(); it != lst.rend(); it++) {
      |                                                                                ^
/usr/include/c++/14/bits/stl_iterator.h:1753:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator!=(const move_iterator<_IteratorL>&, const move_iterator<_IteratorL>&)'
 1753 |     operator!=(const move_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1753:5: note:   template argument deduction/substitution failed:
a.cc:38:80: note:   'std::__cxx11::list<std::pair<int, int> >::iterator' is not derived from 'const std::move_iterator<_IteratorL>'
   38 |         for (list<pair<int, int> >::iterator it = lst.rbegin(); it != lst.rend(); it++) {
      |                                                                                ^
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:1052:5: note: candidate: 'template<class _T1, class _T2> constexpr bool std::operator!=(const pair<_T1, _T2>&, const pair<_T1, _T2>&)'
 1052 |     operator!=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_pair.h:1052:5: note:   template argument deduction/substitution failed:
a.cc:38:80: note:   'std::__cxx11::list<std::pair<int, int> >::iterator' is not derived from 'const std::pair<_T1, _T2>'
   38 |         for (list<pair<int, int> >::iterator it = lst.rbegin(); it != lst.rend(); it++) {
      |                                                                                ^
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:651:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator!=(basic_string_view<_CharT, _Traits>, basic_string_view<_CharT, _Traits>)'
  651 |     operator!=(basic_string_view<_CharT, _Traits> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:651:5: note:   template argument deduction/substitution failed:
a.cc:38:80: note:   'std::_List_iterator<std::pair<int, int> >' is not derived from 'std::basic_string_view<_CharT, _Traits>'
   38 |         for (list<pair<int, int> >::iterator it = lst.rbegin(); it != lst.rend(); it++) {
      |                                                                                ^
/usr/include/c++/14/string_view:658:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator!=(basic_string_view<_CharT, _Traits>, __type_identity_t<basic_string_view<_CharT, _Traits> >)'
  658 |     operator!=(basic_string_view<_CharT, _Traits> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:658:5: note:   template argument deduction/substitution failed:
a.cc:38:80: note:   'std::_List_iterator<std::pair<int, int> >' is not derived from 'std::basic_string_view<_CharT, _Traits>'
   38 |         for (list<pair<int, int> >::iterator it = lst.rbegin(); it != lst.rend(); it++) {
      |                                                                                ^
/usr/include/c++/14/string_view:666:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator!=(__type_identity_t<basic_string_view<_CharT, _Traits> >, basic_string_view<_CharT, _Traits>)'
  666 |     operator!=(__type_identity_t<basic_string_view<_CharT, _Traits>> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:666:5: note:   template argument deduction/substitution failed:
a.cc:38:80: note:   'std::reverse_iterator<std::_List_iterator<std::pair<int, int> > >' is not derived from 'std::basic_string_view<_CharT, _Traits>'
   38 |         for (list<pair<int, int> >::iterator it = lst.rbegin(); it != lst.rend(); it++) {
      |                                                                                ^
/usr/include/c++/14/bits/basic_string.h:3833:5: 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>&)'
 3833 |     operator!=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3833:5: note:   template argument deduction/substitution failed:
a.cc:38:80: note:   'std::__cxx11::list<std::pair<int, int> >::iterator' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   38 |         for (list<pair<int, int> >::iterator it = lst.rbegin(); it != lst.rend(); it++) {
      |                                                                                ^
/usr/include/c++/14/bits/basic_string.h:3847:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const _CharT*, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3847 |     operator!=(const _CharT* __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3847:5: note:   template