Submission #762251

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
762251	2023-06-21T07:03:32 Z	resting	Parking (CEOI22_parking)	C++17	Compilation error	0 ms	0 KB

Main

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

#define int long long

const int mx = 1e5 + 5;
void solve() {
    int n, m; cin >> n >> m;
    vector<vector<int>> v(m, vector<int>(2, 0));
    vector<vector<int>> pos(n);
    vector<int> empty;
    vector<pair<int, int>> res;
    for (int i = 0; i < m; i++) {
        auto& x = v[i];
        cin >> x[0] >> x[1]; x[0]--; x[1]--;
        if (x[0] + 1) pos[x[0]].push_back(i);
        if (x[1] + 1) pos[x[1]].push_back(i);
    }

    vector<int> vis(n, 0);

    auto mov = [&](int x, int y) -> void {
        res.push_back({ x, y });
        if (v[x][1] + 1) {
            if (v[y][0] + 1) swap(v[x][1], v[y][1]);
            else swap(v[x][1], v[y][0]);
        } else {
            if (v[y][0] + 1) swap(v[x][0], v[y][1]);
            else swap(v[x][0], v[y][0]);
        }
    };



    //case 1: trivial case
    auto good = [&](int x) -> bool {
        for (int i = 0; i < 2; i++) {
            if (v[pos[x][0]][1] == -1 && (v[pos[x][1]][1] == x || v[pos[x][1]][1] == -1)) {
                return true;
            }
            swap(pos[x][0], pos[x][1]);
        }
        return false;
    };


    vector<int> q;
    for (int i = 0; i < n; i++) {
        if (pos[i][0] == pos[i][1]) {
            vis[i] = 1;
            continue;
        }
        if (good(i)) {
            q.push_back(i); vis[i] = 1;
        }
    }

    while (!q.empty()) {
        auto x = q.back();
        q.pop_back();
        // cout << "good: " << x << endl;
        mov(pos[x][1], pos[x][0]);
        auto t = v[pos[x][1]][0];
        if (t != -1 && good(t)) { vis[t] = 1; q.push_back(t); }
    }
    for (int i = 0; i < m; i++) {
        auto &x = v;
        if (x[0] + x[1] == -2) empty.push_back(i);
    }
        vector<int> todo;

    bool bad = 0;

    auto clear = [&](int t) {
        if (t == -1) return;
        for (int j = 0; j < 2; j++) {
            // cout << t << "," << pos[t][0] << "," << v[pos[t][0]][1] << endl;
            if (v[pos[t][0]][1] == -1) {
                while (true) {
                    //cout << "t: " << t << endl;
                    if (t != -1) vis[t] = 1;
                    if (t == -1) {
                        //process
                        reverse(todo.begin(), todo.end());
                        empty.push_back(pos[todo.back()][0]);
                        for (auto& x : todo) {
                            mov(pos[x][0], pos[x][1]);
                        }
                        todo.clear();
                        return;
                    } else if (v[pos[t][1]][1] == t) {
                        if (v[pos[t][0]][1] == t) {
                            if (!empty.size()) { cout << -1 << endl;bad = 1;  return; }
                            mov(pos[t][0], empty.back());
                            mov(pos[t][1], empty.back());
                            empty.pop_back();

                            //process
                            reverse(todo.begin(), todo.end());
                            empty.push_back(pos[todo.back()][0]);
                            for (auto& x : todo) {
                                mov(pos[x][0], pos[x][1]);
                            }
                            todo.clear();
                        } else {
                            mov(pos[t][1], pos[t][0]);
                        }
                        t = v[pos[t][1]][0];
                        if (v[pos[t][0]][1] != -1) swap(pos[t][0], pos[t][1]);
                    } else {
                        todo.push_back(t); vis[t] = 1;
                        int p = t;
                        t = v[pos[t][1]][1];
                        if (t != -1 && v[pos[t][0]][0] != p) swap(pos[t][0], pos[t][1]);
                    }
                }
            }
            swap(pos[t][0], pos[t][1]);
        }
    };

    //cout << "case2" << endl;
    //case 2 - strip
    for (int i = 0; i < n; i++) {
        if (vis[i]) continue;
        int t = i;
        clear(t);
        if (bad) return;
    }

    //cout << "case3" << endl;
    //case 3 - circle
    for (int i = 0; i < n; i++) {
        if (vis[i]) continue;
        int t = i;
        if (v[pos[t][0]][1] == t && v[pos[t][1]][1] == t) {
            vis[t] = 1;
            if (!empty.size()) { cout << -1 << endl;return; }
            mov(pos[t][0], empty.back());
            mov(pos[t][1], empty.back());
            empty.pop_back();
            t = v[pos[t][0]][0];
            clear(t); if (bad) return;
        }
    }
    // cout << "case4" << endl;
     //case 4 - finish them
    for (int i = 0; i < n; i++) {
        if (vis[i]) continue;
        int t = i; vis[t] = 1;
        if (v[pos[t][0]][1] != t) swap(pos[t][0], pos[t][1]);
        if (!empty.size()) { cout << -1 << endl;return; }
        int bk = empty.back();
        mov(pos[t][0], bk); pos[t][0] = bk;
        t = v[pos[t][0]][0];

        clear(t);
        if (bad) return;
    }



    cout << res.size() << endl;
    for (auto& x : res) cout << x.first + 1 << " " << x.second + 1 << endl;

    //cout << "result: " << endl;
    //for (auto& x : v) cout << x[0] + 1 << " " << x[1] + 1 << endl;


}

int32_t main() {
    int t = 1;
    //cin >> t;
    while (t--)
        solve();
}

Compilation message

Main.cpp: In function 'void solve()':
Main.cpp:68:18: error: no match for 'operator+' (operand types are '__gnu_cxx::__alloc_traits<std::allocator<std::vector<long long int> >, std::vector<long long int> >::value_type' {aka 'std::vector<long long int>'} and '__gnu_cxx::__alloc_traits<std::allocator<std::vector<long long int> >, std::vector<long long int> >::value_type' {aka 'std::vector<long long int>'})
   68 |         if (x[0] + x[1] == -2) empty.push_back(i);
In file included from /usr/include/c++/10/bits/stl_algobase.h:67,
                 from /usr/include/c++/10/bits/specfun.h:45,
                 from /usr/include/c++/10/cmath:1927,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:41,
                 from Main.cpp:1:
/usr/include/c++/10/bits/stl_iterator.h:508:5: note: candidate: 'template<class _Iterator> constexpr std::reverse_iterator<_Iterator> std::operator+(typename std::reverse_iterator<_Iterator>::difference_type, const std::reverse_iterator<_Iterator>&)'
  508 |     operator+(typename reverse_iterator<_Iterator>::difference_type __n,
      |     ^~~~~~~~
/usr/include/c++/10/bits/stl_iterator.h:508:5: note:   template argument deduction/substitution failed:
Main.cpp:68:23: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::vector<long long int> >, std::vector<long long int> >::value_type' {aka 'std::vector<long long int>'} is not derived from 'const std::reverse_iterator<_Iterator>'
   68 |         if (x[0] + x[1] == -2) empty.push_back(i);
      |                       ^
In file included from /usr/include/c++/10/bits/stl_algobase.h:67,
                 from /usr/include/c++/10/bits/specfun.h:45,
                 from /usr/include/c++/10/cmath:1927,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:41,
                 from Main.cpp:1:
/usr/include/c++/10/bits/stl_iterator.h:1540:5: note: candidate: 'template<class _Iterator> constexpr std::move_iterator<_IteratorL> std::operator+(typename std::move_iterator<_IteratorL>::difference_type, const std::move_iterator<_IteratorL>&)'
 1540 |     operator+(typename move_iterator<_Iterator>::difference_type __n,
      |     ^~~~~~~~
/usr/include/c++/10/bits/stl_iterator.h:1540:5: note:   template argument deduction/substitution failed:
Main.cpp:68:23: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::vector<long long int> >, std::vector<long long int> >::value_type' {aka 'std::vector<long long int>'} is not derived from 'const std::move_iterator<_IteratorL>'
   68 |         if (x[0] + x[1] == -2) empty.push_back(i);
      |                       ^
In file included from /usr/include/c++/10/string:55,
                 from /usr/include/c++/10/bits/locale_classes.h:40,
                 from /usr/include/c++/10/bits/ios_base.h:41,
                 from /usr/include/c++/10/ios:42,
                 from /usr/include/c++/10/istream:38,
                 from /usr/include/c++/10/sstream:38,
                 from /usr/include/c++/10/complex:45,
                 from /usr/include/c++/10/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:54,
                 from Main.cpp:1:
/usr/include/c++/10/bits/basic_string.h:6022:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>&, const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 6022 |     operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/10/bits/basic_string.h:6022:5: note:   template argument deduction/substitution failed:
Main.cpp:68:23: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::vector<long long int> >, std::vector<long long int> >::value_type' {aka 'std::vector<long long int>'} is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   68 |         if (x[0] + x[1] == -2) empty.push_back(i);
      |                       ^
In file included from /usr/include/c++/10/string:56,
                 from /usr/include/c++/10/bits/locale_classes.h:40,
                 from /usr/include/c++/10/bits/ios_base.h:41,
                 from /usr/include/c++/10/ios:42,
                 from /usr/include/c++/10/istream:38,
                 from /usr/include/c++/10/sstream:38,
                 from /usr/include/c++/10/complex:45,
                 from /usr/include/c++/10/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:54,
                 from Main.cpp:1:
/usr/include/c++/10/bits/basic_string.tcc:1160:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const _CharT*, const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 1160 |     operator+(const _CharT* __lhs,
      |     ^~~~~~~~
/usr/include/c++/10/bits/basic_string.tcc:1160:5: note:   template argument deduction/substitution failed:
Main.cpp:68:23: note:   mismatched types 'const _CharT*' and 'std::vector<long long int>'
   68 |         if (x[0] + x[1] == -2) empty.push_back(i);
      |                       ^
In file included from /usr/include/c++/10/string:56,
                 from /usr/include/c++/10/bits/locale_classes.h:40,
                 from /usr/include/c++/10/bits/ios_base.h:41,
                 from /usr/include/c++/10/ios:42,
                 from /usr/include/c++/10/istream:38,
                 from /usr/include/c++/10/sstream:38,
                 from /usr/include/c++/10/complex:45,
                 from /usr/include/c++/10/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:54,
                 from Main.cpp:1:
/usr/include/c++/10/bits/basic_string.tcc:1180:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(_CharT, const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 1180 |     operator+(_CharT __lhs, const basic_string<_CharT, _Traits, _Alloc>& __rhs)
      |     ^~~~~~~~
/usr/include/c++/10/bits/basic_string.tcc:1180:5: note:   template argument deduction/substitution failed:
Main.cpp:68:23: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::vector<long long int> >, std::vector<long long int> >::value_type' {aka 'std::vector<long long int>'} is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   68 |         if (x[0] + x[1] == -2) empty.push_back(i);
      |                       ^
In file included from /usr/include/c++/10/string:55,
                 from /usr/include/c++/10/bits/locale_classes.h:40,
                 from /usr/include/c++/10/bits/ios_base.h:41,
                 from /usr/include/c++/10/ios:42,
                 from /usr/include/c++/10/istream:38,
                 from /usr/include/c++/10/sstream:38,
                 from /usr/include/c++/10/complex:45,
                 from /usr/include/c++/10/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:54,
                 from Main.cpp:1:
/usr/include/c++/10/bits/basic_string.h:6059:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>&, const _CharT*)'
 6059 |     operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/10/bits/basic_string.h:6059:5: note:   template argument deduction/substitution failed:
Main.cpp:68:23: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::vector<long long int> >, std::vector<long long int> >::value_type' {aka 'std::vector<long long int>'} is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   68 |         if (x[0] + x[1] == -2) empty.push_back(i);
      |                       ^
In file included from /usr/include/c++/10/string:55,
                 from /usr/include/c++/10/bits/locale_classes.h:40,
                 from /usr/include/c++/10/bits/ios_base.h:41,
                 from /usr/include/c++/10/ios:42,
                 from /usr/include/c++/10/istream:38,
                 from /usr/include/c++/10/sstream:38,
                 from /usr/include/c++/10/complex:45,
                 from /usr/include/c++/10/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:54,
                 from Main.cpp:1:
/usr/include/c++/10/bits/basic_string.h:6075:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>&, _CharT)'
 6075 |     operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs, _CharT __rhs)
      |     ^~~~~~~~
/usr/include/c++/10/bits/basic_string.h:6075:5: note:   template argument deduction/substitution failed:
Main.cpp:68:23: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::vector<long long int> >, std::vector<long long int> >::value_type' {aka 'std::vector<long long int>'} is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   68 |         if (x[0] + x[1] == -2) empty.push_back(i);
      |                       ^
In file included from /usr/include/c++/10/string:55,
                 from /usr/include/c++/10/bits/locale_classes.h:40,
                 from /usr/include/c++/10/bits/ios_base.h:41,
                 from /usr/include/c++/10/ios:42,
                 from /usr/include/c++/10/istream:38,
                 from /usr/include/c++/10/sstream:38,
                 from /usr/include/c++/10/complex:45,
                 from /usr/include/c++/10/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:54,
                 from Main.cpp:1:
/usr/include/c++/10/bits/basic_string.h:6087:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(std::__cxx11::basic_string<_CharT, _Traits, _Allocator>&&, const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 6087 |     operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
      |     ^~~~~~~~
/usr/include/c++/10/bits/basic_string.h:6087:5: note:   template argument deduction/substitution failed:
Main.cpp:68:23: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::vector<long long int> >, std::vector<long long int> >::value_type' {aka 'std::vector<long long int>'} is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   68 |         if (x[0] + x[1] == -2) empty.push_back(i);
      |                       ^
In file included from /usr/include/c++/10/string:55,
                 from /usr/include/c++/10/bits/locale_classes.h:40,
                 from /usr/include/c++/10/bits/ios_base.h:41,
                 from /usr/include/c++/10/ios:42,
                 from /usr/include/c++/10/istream:38,
                 from /usr/include/c++/10/sstream:38,
                 from /usr/include/c++/10/complex:45,
                 from /usr/include/c++/10/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:54,
                 from Main.cpp:1:
/usr/include/c++/10/bits/basic_string.h:6093:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>&, std::__cxx11::basic_string<_CharT, _Traits, _Allocator>&&)'
 6093 |     operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/10/bits/basic_string.h:6093:5: note:   template argument deduction/substitution failed:
Main.cpp:68:23: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::vector<long long int> >, std::vector<long long int> >::value_type' {aka 'std::vector<long long int>'} is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   68 |         if (x[0] + x[1] == -2) empty.push_back(i);
      |                       ^
In file included from /usr/include/c++/10/string:55,
                 from /usr/include/c++/10/bits/locale_classes.h:40,
                 from /usr/include/c++/10/bits/ios_base.h:41,
                 from /usr/include/c++/10/ios:42,
                 from /usr/include/c++/10/istream:38,
                 from /usr/include/c++/10/sstream:38,
                 from /usr/include/c++/10/complex:45,
                 from /usr/include/c++/10/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:54,
                 from Main.cpp:1:
/usr/include/c++/10/bits/basic_string.h:6099:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(std::__cxx11::basic_string<_CharT, _Traits, _Allocator>&&, std::__cxx11::basic_string<_CharT, _Traits, _Allocator>&&)'
 6099 |     operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
      |     ^~~~~~~~
/usr/include/c++/10/bits/basic_string.h:6099:5: note:   template argument deduction/substitution failed:
Main.cpp:68:23: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::vector<long long int> >, std::vector<long long int> >::value_type' {aka 'std::vector<long long int>'} is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   68 |         if (x[0] + x[1] == -2) empty.push_back(i);
      |                       ^
In file included from /usr/include/c++/10/string:55,
                 from /usr/include/c++/10/bits/locale_classes.h:40,
                 from /usr/include/c++/10/bits/ios_base.h:41,
                 from /usr/include/c++/10/ios:42,
                 from /usr/include/c++/10/istream:38,
                 from /usr/include/c++/10/sstream:38,
                 from /usr/include/c++/10/complex:45,
                 from /usr/include/c++/10/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:54,
                 from Main.cpp:1:
/usr/include/c++/10/bits/basic_string.h:6121:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const _CharT*, std::__cxx11::basic_string<_CharT, _Traits, _Allocator>&&)'
 6121 |     operator+(const _CharT* __lhs,
      |     ^~~~~~~~
/usr/include/c++/10/bits/basic_string.h:6121:5: note:   template argument deduction/substitution failed:
Main.cpp:68:23: note:   mismatched types 'const _CharT*' and 'std::vector<long long int>'
   68 |         if (x[0] + x[1] == -2) empty.push_back(i);
      |                       ^
In file included from /usr/include/c++/10/string:55,
                 from /usr/include/c++/10/bits/locale_classes.h:40,
                 from /usr/include/c++/10/bits/ios_base.h:41,
                 from /usr/include/c++/10/ios:42,
                 from /usr/include/c++/10/istream:38,
                 from /usr/include/c++/10/sstream:38,
                 from /usr/include/c++/10/complex:45,
                 from /usr/include/c++/10/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:54,
                 from Main.cpp:1:
/usr/include/c++/10/bits/basic_string.h:6127:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(_CharT, std::__cxx11::basic_string<_CharT, _Traits, _Allocator>&&)'
 6127 |     operator+(_CharT __lhs,
      |     ^~~~~~~~
/usr/include/c++/10/bits/basic_string.h:6127:5: note:   template argument deduction/substitution failed:
Main.cpp:68:23: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::vector<long long int> >, std::vector<long long int> >::value_type' {aka 'std::vector<long long int>'} is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   68 |         if (x[0] + x[1] == -2) empty.push_back(i);
      |                       ^
In file included from /usr/include/c++/10/string:55,
                 from /usr/include/c++/10/bits/locale_classes.h:40,
                 from /usr/include/c++/10/bits/ios_base.h:41,
                 from /usr/include/c++/10/ios:42,
                 from /usr/include/c++/10/istream:38,
                 from /usr/include/c++/10/sstream:38,
                 from /usr/include/c++/10/complex:45,
                 from /usr/include/c++/10/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:54,
                 from Main.cpp:1:
/usr/include/c++/10/bits/basic_string.h:6133:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(std::__cxx11::basic_string<_CharT, _Traits, _Allocator>&&, const _CharT*)'
 6133 |     operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
      |     ^~~~~~~~
/usr/include/c++/10/bits/basic_string.h:6133:5: note:   template argument deduction/substitution failed:
Main.cpp:68:23: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::vector<long long int> >, std::vector<long long int> >::value_type' {aka 'std::vector<long long int>'} is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   68 |         if (x[0] + x[1] == -2) empty.push_back(i);
      |                       ^
In file included from /usr/include/c++/10/string:55,
                 from /usr/include/c++/10/bits/locale_classes.h:40,
                 from /usr/include/c++/10/bits/ios_base.h:41,
                 from /usr/include/c++/10/ios:42,
                 from /usr/include/c++/10/istream:38,
                 from /usr/include/c++/10/sstream:38,
                 from /usr/include/c++/10/complex:45,
                 from /usr/include/c++/10/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:54,
                 from Main.cpp:1:
/usr/include/c++/10/bits/basic_string.h:6139:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(std::__cxx11::basic_string<_CharT, _Traits, _Allocator>&&, _CharT)'
 6139 |     operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
      |     ^~~~~~~~
/usr/include/c++/10/bits/basic_string.h:6139:5: note:   template argument deduction/substitution failed:
Main.cpp:68:23: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::vector<long long int> >, std::vector<long long int> >::value_type' {aka 'std::vector<long long int>'} is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   68 |         if (x[0] + x[1] == -2) empty.push_back(i);
      |                       ^
In file included from /usr/include/c++/10/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:54,
                 from Main.cpp:1:
/usr/include/c++/10/