Language: C++

#include <iostream>
#include <stack>
#include <vector>
#include <string>
#include <algorithm>
using namespace std;

int main(){
	// stack<long> S1, ans;
	// stack<pair<long, long> > S2;
	// char ch;
	// long sum = 0;
	// for (long i = 0; cin >> ch; i++){
	// 	if (ch == '\\') S1.push(i);
	// 	else if (ch == '/' && S1.size() > 0){
	// 		long j = S1.top(); S1.pop();
	// 		sum += i - j;
	// 		long a = i - j;
	// 		while (S2.size() > 0 && S2.top().first > j){
	// 			a += S2.top().second; S2.pop();
	// 		}
	// 		S2.push(make_pair(j, a));
	// 	}
	// }
	// cout << sum << endl << S2.size();
	// while (S2.size() > 0){ans.push(S2.top().second); S2.pop();}
	// while (ans.size() > 0){cout << " " << ans.top(); ans.pop();}
	// cout << endl;
	vector<long> S1, ans;
	vector<pair<long, long> > S2;
	char ch;
	long sum = 0;
	for (long i = 0; cin >> ch; i++){
		if (ch == '\\') S1.push_front(i);
		else if (ch == '/' && S1.size() > 0){
			long j = S1[0]; S1.erase(S1.begin());
			long a = i - j;
			sum += i - j;
			while (S2.size() > 0 && S2[0].first > j){
				a += S2[0].second; S2.erase(S2.begin());
			}
			S2.push_front(make_pair(j, a));
		}
	}
	cout << sum << endl << S2.size();
	while (S2.size() > 0){cout << " " << S2[S2.size() - 1]; S2.pop_back();}
	cout << endl;
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:34:36: error: 'class std::vector<long int>' has no member named 'push_front'
   34 |                 if (ch == '\\') S1.push_front(i);
      |                                    ^~~~~~~~~~
a.cc:42:28: error: 'class std::vector<std::pair<long int, long int> >' has no member named 'push_front'
   42 |                         S2.push_front(make_pair(j, a));
      |                            ^~~~~~~~~~
a.cc:46:43: error: no match for 'operator<<' (operand types are 'std::basic_ostream<char>' and '__gnu_cxx::__alloc_traits<std::allocator<std::pair<long int, long int> >, std::pair<long int, long int> >::value_type' {aka 'std::pair<long int, long int>'})
   46 |         while (S2.size() > 0){cout << " " << S2[S2.size() - 1]; S2.pop_back();}
In file included from /usr/include/c++/14/iostream:41,
                 from a.cc:1:
/usr/include/c++/14/ostream:116:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(__ostream_type& (*)(__ostream_type&)) [with _CharT = char; _Traits = std::char_traits<char>; __ostream_type = std::basic_ostream<char>]'
  116 |       operator<<(__ostream_type& (*__pf)(__ostream_type&))
      |       ^~~~~~~~
/usr/include/c++/14/ostream:116:36: note:   no known conversion for argument 1 from '__gnu_cxx::__alloc_traits<std::allocator<std::pair<long int, long int> >, std::pair<long int, long int> >::value_type' {aka 'std::pair<long int, long int>'} to 'std::basic_ostream<char>::__ostream_type& (*)(std::basic_ostream<char>::__ostream_type&)' {aka 'std::basic_ostream<char>& (*)(std::basic_ostream<char>&)'}
  116 |       operator<<(__ostream_type& (*__pf)(__ostream_type&))
      |                  ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/ostream:125:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(__ios_type& (*)(__ios_type&)) [with _CharT = char; _Traits = std::char_traits<char>; __ostream_type = std::basic_ostream<char>; __ios_type = std::basic_ios<char>]'
  125 |       operator<<(__ios_type& (*__pf)(__ios_type&))
      |       ^~~~~~~~
/usr/include/c++/14/ostream:125:32: note:   no known conversion for argument 1 from '__gnu_cxx::__alloc_traits<std::allocator<std::pair<long int, long int> >, std::pair<long int, long int> >::value_type' {aka 'std::pair<long int, long int>'} to 'std::basic_ostream<char>::__ios_type& (*)(std::basic_ostream<char>::__ios_type&)' {aka 'std::basic_ios<char>& (*)(std::basic_ios<char>&)'}
  125 |       operator<<(__ios_type& (*__pf)(__ios_type&))
      |                  ~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~
/usr/include/c++/14/ostream:135:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(std::ios_base& (*)(std::ios_base&)) [with _CharT = char; _Traits = std::char_traits<char>; __ostream_type = std::basic_ostream<char>]'
  135 |       operator<<(ios_base& (*__pf) (ios_base&))
      |       ^~~~~~~~
/usr/include/c++/14/ostream:135:30: note:   no known conversion for argument 1 from '__gnu_cxx::__alloc_traits<std::allocator<std::pair<long int, long int> >, std::pair<long int, long int> >::value_type' {aka 'std::pair<long int, long int>'} to 'std::ios_base& (*)(std::ios_base&)'
  135 |       operator<<(ios_base& (*__pf) (ios_base&))
      |                  ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~
/usr/include/c++/14/ostream:174:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(long int) [with _CharT = char; _Traits = std::char_traits<char>; __ostream_type = std::basic_ostream<char>]'
  174 |       operator<<(long __n)
      |       ^~~~~~~~
/usr/include/c++/14/ostream:174:23: note:   no known conversion for argument 1 from '__gnu_cxx::__alloc_traits<std::allocator<std::pair<long int, long int> >, std::pair<long int, long int> >::value_type' {aka 'std::pair<long int, long int>'} to 'long int'
  174 |       operator<<(long __n)
      |                  ~~~~~^~~
/usr/include/c++/14/ostream:178:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(long unsigned int) [with _CharT = char; _Traits = std::char_traits<char>; __ostream_type = std::basic_ostream<char>]'
  178 |       operator<<(unsigned long __n)
      |       ^~~~~~~~
/usr/include/c++/14/ostream:178:32: note:   no known conversion for argument 1 from '__gnu_cxx::__alloc_traits<std::allocator<std::pair<long int, long int> >, std::pair<long int, long int> >::value_type' {aka 'std::pair<long int, long int>'} to 'long unsigned int'
  178 |       operator<<(unsigned long __n)
      |                  ~~~~~~~~~~~~~~^~~
/usr/include/c++/14/ostream:182:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(bool) [with _CharT = char; _Traits = std::char_traits<char>; __ostream_type = std::basic_ostream<char>]'
  182 |       operator<<(bool __n)
      |       ^~~~~~~~
/usr/include/c++/14/ostream:182:23: note:   no known conversion for argument 1 from '__gnu_cxx::__alloc_traits<std::allocator<std::pair<long int, long int> >, std::pair<long int, long int> >::value_type' {aka 'std::pair<long int, long int>'} to 'bool'
  182 |       operator<<(bool __n)
      |                  ~~~~~^~~
In file included from /usr/include/c++/14/ostream:1022:
/usr/include/c++/14/bits/ostream.tcc:96:5: note: candidate: 'std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(short int) [with _CharT = char; _Traits = std::char_traits<char>]'
   96 |     basic_ostream<_CharT, _Traits>::
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/ostream.tcc:97:22: note:   no known conversion for argument 1 from '__gnu_cxx::__alloc_traits<std::allocator<std::pair<long int, long int> >, std::pair<long int, long int> >::value_type' {aka 'std::pair<long int, long int>'} to 'short int'
   97 |     operator<<(short __n)
      |                ~~~~~~^~~
/usr/include/c++/14/ostream:189:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(short unsigned int) [with _CharT = char; _Traits = std::char_traits<char>; __ostream_type = std::basic_ostream<char>]'
  189 |       operator<<(unsigned short __n)
      |       ^~~~~~~~
/usr/include/c++/14/ostream:189:33: note:   no known conversion for argument 1 from '__gnu_cxx::__alloc_traits<std::allocator<std::pair<long int, long int> >, std::pair<long int, long int> >::value_type' {aka 'std::pair<long int, long int>'} to 'short unsigned int'
  189 |       operator<<(unsigned short __n)
      |                  ~~~~~~~~~~~~~~~^~~
/usr/include/c++/14/bits/ostream.tcc:110:5: note: candidate: 'std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(int) [with _CharT = char; _Traits = std::char_traits<char>]'
  110 |     basic_ostream<_CharT, _Traits>::
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/ostream.tcc:111:20: note:   no known conversion for argument 1 from '__gnu_cxx::__alloc_traits<std::allocator<std::pair<long int, long int> >, std::pair<long int, long int> >::value_type' {aka 'std::pair<long int, long int>'} to 'int'
  111 |     operator<<(int __n)
      |                ~~~~^~~
/usr/include/c++/14/ostream:200:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(unsigned int) [with _CharT = char; _Traits = std::char_traits<char>; __ostream_type = std::basic_ostream<char>]'
  200 |       operator<<(unsigned int __n)
      |       ^~~~~~~~
/usr/include/c++/14/ostream:200:31: note:   no known conversion for argument 1 from '__gnu_cxx::__alloc_traits<std::allocator<std::pair<long int, long int> >, std::pair<long int, long int> >::value_type' {aka 'std::pair<long int, long int>'} to 'unsigned int'
  200 |       operator<<(unsigned int __n)
      |                  ~~~~~~~~~~~~~^~~
/usr/include/c++/14/ostream:211:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(long long int) [with _CharT = char; _Traits = std::char_traits<char>; __ostream_type = std::basic_ostream<char>]'
  211 |       operator<<(long long __n)
      |       ^~~~~~~~
/usr/include/c++/14/ostream:211:28: note:   no known conversion for argument 1 from '__gnu_cxx::__alloc_traits<std::allocator<std::pair<long int, long int> >, std::pair<long int, long int> >::value_type' {aka 'std::pair<long int, long int>'} to 'long long int'
  211 |       operator<<(long long __n)
      |                  ~~~~~~~~~~^~~
/usr/include/c++/14/ostream:215:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(long long unsigned int) [with _CharT = char; _Traits = std::char_traits<char>; __ostream_type = std::basic_ostream<char>]'
  215 |       operator<<(unsigned long long __n)
      |       ^~~~~~~~
/usr/include/c++/14/ostream:215:37: note:   no known conversion for argument 1 from '__gnu_cxx::__alloc_traits<std::allocator<std::pair<long int, long int> >, std::pair<long int, long int> >::value_type' {aka 'std::pair<long int, long int>'} to 'long long unsigned int'
  215 |       operator<<(unsigned long long __n)
      |                  ~~~~~~~~~~~~~~~~~~~^~~
/usr/include/c++/14/ostream:231:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(double) [with _CharT = char; _Traits = std::char_traits<char>; __ostream_type = std::basic_ostream<char>]'
  231 |       operator<<(double __f)
      |       ^~~~~~~~
/usr/include/c++/14/ostream:231:25: note:   no known conversion for argument 1 from '__gnu_cxx::__alloc_traits<std::allocator<std::pair<long int, long int> >, std::pair<long int, long int> >::value_type' {aka 'std::pair<long int, long int>'} to 'double'
  231 |       operator<<(double __f)
      |                  ~~~~~~~^~~
/usr/include/c++/14/ostream:235:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type