Submission #418145

#TimeUsernameProblemLanguageResultExecution timeMemory
418145usachevd0Sky Walking (IOI19_walk)C++17
Compilation error
0 ms0 KiB
#include <bits/stdc++.h> #ifndef LOCAL #include "walk.h" #endif using namespace std; #define fi first #define se second #define mp make_pair #define pb push_back #define all(a) (a).begin(), (a).end() #define Time (clock() * 1.0 / CLOCKS_PER_SEC) using ll = long long; using ull = unsigned long long; using pii = pair<int, int>; using pil = pair<int, ll>; using pli = pair<ll, int>; using pll = pair<ll, ll>; using ld = long double; template<typename T1, typename T2> bool chkmin(T1& x, T2 y) { return y < x ? (x = y, true) : false; } template<typename T1, typename T2> bool chkmax(T1& x, T2 y) { return y > x ? (x = y, true) : false; } void debug_out() { cerr << endl; } template<typename T1, typename... T2> void debug_out(T1 A, T2... B) { cerr << ' ' << A; debug_out(B...); } template<typename T> void mdebug_out(T* a, int n) { for (int i = 0; i < n; ++i) cerr << a[i] << ' '; cerr << endl; } #ifdef LOCAL #define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__) #define mdebug(a, n) cerr << #a << ": ", mdebug_out(a, n) #else #define debug(...) 1337 #define mdebug(a, n) 1337 #endif template<typename T> ostream& operator << (ostream& stream, const vector<T>& v) { for (auto& x : v) stream << x << ' '; return stream; } template<typename T1, typename T2> ostream& operator << (ostream& stream, const pair<T1, T2>& p) { return stream << p.first << ' ' << p.second; } const ll INF64 = 1e18; const int maxN = 100005; int n, m; vector<int> bg[maxN], en[maxN]; ll V[maxN]; namespace dsu { int q[maxN]; void init() { memset(q, 255, sizeof q); } int gt(int x) { return q[x] < 0 ? x : q[x] = gt(q[x]); } bool join(int x, int y) { // y is the parent of x x = gt(x), y = gt(y); if (x == y) return false; //if (-q[x] > -q[y]) swap(x, y); q[y] += q[x]; q[x] = y; return true; } } ll min_distance(vector<int> X, vector<int> H, vector<int> L, vector<int> R, vector<int> Y, int SI, int TI) { n = X.size(), m = L.size(); assert(SI == 0 && TI == n - 1); for (int j = 0; j < m; ++j) { int l = L[j], r = R[j]; bg[l].push_back(j); en[r].push_back(j); } dsu::init(); fill(V, V + m, INF64); auto gv = [&](int j) -> ll { int r = dsu::gt(j); return V[r] + Y[r] - Y[j]; }; set<pii> a; for (int j : bg[0]) { int y = Y[j]; a.insert({y, j}); V[j] = y; } set<pii> needUp; for (int i = 1; i < n; ++i) { if (a.empty()) return -1; while (!needUp.empty()) { int y = -needUp.begin()->fi; if (y > H[i]) break; int j = needUp.begin()->se; needUp.erase(needUp.begin()); auto it = a.upper_bound({Y[j], j}); if (it != a.end() && it->fi <= H[i]) { ll fv = it->fi - Y[j] + gv(it->se); if (fv <= V[j]) { V[j] = fv; dsu::join(j, it->se); } } } for (int j : bg[i]) { auto it = a.lower_bound({y, -1}); if (it != a.begin()) { auto pit = prev(it); chkmin(V[j], Y[j] - it->fi + gv(it->se)); } if (it != a.end() && it->fi <= H[i]) { ll fv = it->fi - Y[j] + gv(it->se); if (fv <= V[j]) { V[j] = fv; dsu::join(j, it->se); } } else if (it != a.end()) needUp.insert({-it->fi, j}); a.insert({y, j}); } if (i == n - 1) break; for (int j : en[i]) { int y = Y[j]; a.erase({y, j}); } // debug(i); // for (auto el : a) cerr << el << ' ' << gv(el.se) << " "; cerr << endl; } ll ans = INF64; for (auto& [y, j] : a) { chkmin(ans, X[n - 1] - X[0] + y + gv(j)); } return ans; } #ifdef LOCAL int32_t main() { #ifdef LOCAL freopen("in", "r", stdin); #endif ios::sync_with_stdio(0); cin.tie(0); int n, m; assert(2 == scanf("%d%d", &n, &m)); vector<int> x(n), h(n); for (int i = 0; i < n; i++) assert(2 == scanf("%d%d", &x[i], &h[i])); vector<int> l(m), r(m), y(m); for (int i = 0; i < m; i++) assert(3 == scanf("%d%d%d", &l[i], &r[i], &y[i])); int s, g; assert(2 == scanf("%d%d", &s, &g)); fclose(stdin); long long result = min_distance(x, h, l, r, y, s, g); printf("%lld\n", result); fclose(stdout); return 0; } #endif

Compilation message (stderr)

walk.cpp: In function 'll min_distance(std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>, int, int)':
walk.cpp:126:38: error: 'y' was not declared in this scope
  126 |             auto it = a.lower_bound({y, -1});
      |                                      ^
walk.cpp:126:44: error: no matching function for call to 'std::set<std::pair<int, int> >::lower_bound(<brace-enclosed initializer list>)'
  126 |             auto it = a.lower_bound({y, -1});
      |                                            ^
In file included from /usr/include/c++/10/set:61,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:87,
                 from walk.cpp:1:
/usr/include/c++/10/bits/stl_set.h:829:7: note: candidate: 'std::set<_Key, _Compare, _Alloc>::iterator std::set<_Key, _Compare, _Alloc>::lower_bound(const key_type&) [with _Key = std::pair<int, int>; _Compare = std::less<std::pair<int, int> >; _Alloc = std::allocator<std::pair<int, int> >; std::set<_Key, _Compare, _Alloc>::iterator = std::_Rb_tree<std::pair<int, int>, std::pair<int, int>, std::_Identity<std::pair<int, int> >, std::less<std::pair<int, int> >, std::allocator<std::pair<int, int> > >::const_iterator; std::set<_Key, _Compare, _Alloc>::key_type = std::pair<int, int>]'
  829 |       lower_bound(const key_type& __x)
      |       ^~~~~~~~~~~
/usr/include/c++/10/bits/stl_set.h:829:35: note:   no known conversion for argument 1 from '<brace-enclosed initializer list>' to 'const key_type&' {aka 'const std::pair<int, int>&'}
  829 |       lower_bound(const key_type& __x)
      |                   ~~~~~~~~~~~~~~~~^~~
/usr/include/c++/10/bits/stl_set.h:833:7: note: candidate: 'std::set<_Key, _Compare, _Alloc>::const_iterator std::set<_Key, _Compare, _Alloc>::lower_bound(const key_type&) const [with _Key = std::pair<int, int>; _Compare = std::less<std::pair<int, int> >; _Alloc = std::allocator<std::pair<int, int> >; std::set<_Key, _Compare, _Alloc>::const_iterator = std::_Rb_tree<std::pair<int, int>, std::pair<int, int>, std::_Identity<std::pair<int, int> >, std::less<std::pair<int, int> >, std::allocator<std::pair<int, int> > >::const_iterator; std::set<_Key, _Compare, _Alloc>::key_type = std::pair<int, int>]'
  833 |       lower_bound(const key_type& __x) const
      |       ^~~~~~~~~~~
/usr/include/c++/10/bits/stl_set.h:833:35: note:   no known conversion for argument 1 from '<brace-enclosed initializer list>' to 'const key_type&' {aka 'const std::pair<int, int>&'}
  833 |       lower_bound(const key_type& __x) const
      |                   ~~~~~~~~~~~~~~~~^~~
/usr/include/c++/10/bits/stl_set.h:839:2: note: candidate: 'template<class _Kt> decltype ((std::set<_Key, _Compare, _Alloc>::iterator)(((std::set<_Key, _Compare, _Alloc>*)this)->std::set<_Key, _Compare, _Alloc>::_M_t._M_lower_bound_tr(__x))) std::set<_Key, _Compare, _Alloc>::lower_bound(const _Kt&) [with _Kt = _Kt; _Key = std::pair<int, int>; _Compare = std::less<std::pair<int, int> >; _Alloc = std::allocator<std::pair<int, int> >]'
  839 |  lower_bound(const _Kt& __x)
      |  ^~~~~~~~~~~
/usr/include/c++/10/bits/stl_set.h:839:2: note:   template argument deduction/substitution failed:
walk.cpp:126:44: note:   couldn't deduce template parameter '_Kt'
  126 |             auto it = a.lower_bound({y, -1});
      |                                            ^
In file included from /usr/include/c++/10/set:61,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:87,
                 from walk.cpp:1:
/usr/include/c++/10/bits/stl_set.h:845:2: note: candidate: 'template<class _Kt> decltype ((std::set<_Key, _Compare, _Alloc>::const_iterator)(((const std::set<_Key, _Compare, _Alloc>*)this)->std::set<_Key, _Compare, _Alloc>::_M_t._M_lower_bound_tr(__x))) std::set<_Key, _Compare, _Alloc>::lower_bound(const _Kt&) const [with _Kt = _Kt; _Key = std::pair<int, int>; _Compare = std::less<std::pair<int, int> >; _Alloc = std::allocator<std::pair<int, int> >]'
  845 |  lower_bound(const _Kt& __x) const
      |  ^~~~~~~~~~~
/usr/include/c++/10/bits/stl_set.h:845:2: note:   template argument deduction/substitution failed:
walk.cpp:126:44: note:   couldn't deduce template parameter '_Kt'
  126 |             auto it = a.lower_bound({y, -1});
      |                                            ^
walk.cpp:139:43: error: no matching function for call to 'std::set<std::pair<int, int> >::insert(<brace-enclosed initializer list>)'
  139 |                 needUp.insert({-it->fi, j});
      |                                           ^
In file included from /usr/include/c++/10/set:61,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:87,
                 from walk.cpp:1:
/usr/include/c++/10/bits/stl_set.h:509:7: note: candidate: 'std::pair<typename std::_Rb_tree<_Key, _Key, std::_Identity<_Tp>, _Compare, typename __gnu_cxx::__alloc_traits<_Alloc>::rebind<_Key>::other>::const_iterator, bool> std::set<_Key, _Compare, _Alloc>::insert(const value_type&) [with _Key = std::pair<int, int>; _Compare = std::less<std::pair<int, int> >; _Alloc = std::allocator<std::pair<int, int> >; typename std::_Rb_tree<_Key, _Key, std::_Identity<_Tp>, _Compare, typename __gnu_cxx::__alloc_traits<_Alloc>::rebind<_Key>::other>::const_iterator = std::_Rb_tree<std::pair<int, int>, std::pair<int, int>, std::_Identity<std::pair<int, int> >, std::less<std::pair<int, int> >, std::allocator<std::pair<int, int> > >::const_iterator; std::set<_Key, _Compare, _Alloc>::value_type = std::pair<int, int>]'
  509 |       insert(const value_type& __x)
      |       ^~~~~~
/usr/include/c++/10/bits/stl_set.h:509:32: note:   no known conversion for argument 1 from '<brace-enclosed initializer list>' to 'const value_type&' {aka 'const std::pair<int, int>&'}
  509 |       insert(const value_type& __x)
      |              ~~~~~~~~~~~~~~~~~~^~~
/usr/include/c++/10/bits/stl_set.h:518:7: note: candidate: 'std::pair<typename std::_Rb_tree<_Key, _Key, std::_Identity<_Tp>, _Compare, typename __gnu_cxx::__alloc_traits<_Alloc>::rebind<_Key>::other>::const_iterator, bool> std::set<_Key, _Compare, _Alloc>::insert(std::set<_Key, _Compare, _Alloc>::value_type&&) [with _Key = std::pair<int, int>; _Compare = std::less<std::pair<int, int> >; _Alloc = std::allocator<std::pair<int, int> >; typename std::_Rb_tree<_Key, _Key, std::_Identity<_Tp>, _Compare, typename __gnu_cxx::__alloc_traits<_Alloc>::rebind<_Key>::other>::const_iterator = std::_Rb_tree<std::pair<int, int>, std::pair<int, int>, std::_Identity<std::pair<int, int> >, std::less<std::pair<int, int> >, std::allocator<std::pair<int, int> > >::const_iterator; std::set<_Key, _Compare, _Alloc>::value_type = std::pair<int, int>]'
  518 |       insert(value_type&& __x)
      |       ^~~~~~
/usr/include/c++/10/bits/stl_set.h:518:27: note:   no known conversion for argument 1 from '<brace-enclosed initializer list>' to 'std::set<std::pair<int, int> >::value_type&&' {aka 'std::pair<int, int>&&'}
  518 |       insert(value_type&& __x)
      |              ~~~~~~~~~~~~~^~~
/usr/include/c++/10/bits/stl_set.h:546:7: note: candidate: 'std::set<_Key, _Compare, _Alloc>::iterator std::set<_Key, _Compare, _Alloc>::insert(std::set<_Key, _Compare, _Alloc>::const_iterator, const value_type&) [with _Key = std::pair<int, int>; _Compare = std::less<std::pair<int, int> >; _Alloc = std::allocator<std::pair<int, int> >; std::set<_Key, _Compare, _Alloc>::iterator = std::_Rb_tree<std::pair<int, int>, std::pair<int, int>, std::_Identity<std::pair<int, int> >, std::less<std::pair<int, int> >, std::allocator<std::pair<int, int> > >::const_iterator; std::set<_Key, _Compare, _Alloc>::const_iterator = std::_Rb_tree<std::pair<int, int>, std::pair<int, int>, std::_Identity<std::pair<int, int> >, std::less<std::pair<int, int> >, std::allocator<std::pair<int, int> > >::const_iterator; std::set<_Key, _Compare, _Alloc>::value_type = std::pair<int, int>]'
  546 |       insert(const_iterator __position, const value_type& __x)
      |       ^~~~~~
/usr/include/c++/10/bits/stl_set.h:546:7: note:   candidate expects 2 arguments, 1 provided
/usr/include/c++/10/bits/stl_set.h:551:7: note: candidate: 'std::set<_Key, _Compare, _Alloc>::iterator std::set<_Key, _Compare, _Alloc>::insert(std::set<_Key, _Compare, _Alloc>::const_iterator, std::set<_Key, _Compare, _Alloc>::value_type&&) [with _Key = std::pair<int, int>; _Compare = std::less<std::pair<int, int> >; _Alloc = std::allocator<std::pair<int, int> >; std::set<_Key, _Compare, _Alloc>::iterator = std::_Rb_tree<std::pair<int, int>, std::pair<int, int>, std::_Identity<std::pair<int, int> >, std::less<std::pair<int, int> >, std::allocator<std::pair<int, int> > >::const_iterator; std::set<_Key, _Compare, _Alloc>::const_iterator = std::_Rb_tree<std::pair<int, int>, std::pair<int, int>, std::_Identity<std::pair<int, int> >, std::less<std::pair<int, int> >, std::allocator<std::pair<int, int> > >::const_iterator; std::set<_Key, _Compare, _Alloc>::value_type = std::pair<int, int>]'
  551 |       insert(const_iterator __position, value_type&& __x)
      |       ^~~~~~
/usr/include/c++/10/bits/stl_set.h:551:7: note:   candidate expects 2 arguments, 1 provided
/usr/include/c++/10/bits/stl_set.h:566:2: note: candidate: 'template<class _InputIterator> void std::set<_Key, _Compare, _Alloc>::insert(_InputIterator, _InputIterator) [with _InputIterator = _InputIterator; _Key = std::pair<int, int>; _Compare = std::less<std::pair<int, int> >; _Alloc = std::allocator<std::pair<int, int> >]'
  566 |  insert(_InputIterator __first, _InputIterator __last)
      |  ^~~~~~
/usr/include/c++/10/bits/stl_set.h:566:2: note:   template argument deduction/substitution failed:
walk.cpp:139:43: note:   candidate expects 2 arguments, 1 provided
  139 |                 needUp.insert({-it->fi, j});
      |                                           ^
In file included from /usr/include/c++/10/set:61,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:87,
                 from walk.cpp:1:
/usr/include/c++/10/bits/stl_set.h:578:7: note: candidate: 'void std::set<_Key, _Compare, _Alloc>::insert(std::initializer_list<_Tp>) [with _Key = std::pair<int, int>; _Compare = std::less<std::pair<int, int> >; _Alloc = std::allocator<std::pair<int, int> >]'
  578 |       insert(initializer_list<value_type> __l)
      |       ^~~~~~
/usr/include/c++/10/bits/stl_set.h:578:43: note:   no known conversion for argument 1 from '<brace-enclosed initializer list>' to 'std::initializer_list<std::pair<int, int> >'
  578 |       insert(initializer_list<value_type> __l)
      |              ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~
/usr/include/c++/10/bits/stl_set.h:598:7: note: candidate: 'std::set<_Key, _Compare, _Alloc>::insert_return_type std::set<_Key, _Compare, _Alloc>::insert(std::set<_Key, _Compare, _Alloc>::node_type&&) [with _Key = std::pair<int, int>; _Compare = std::less<std::pair<int, int> >; _Alloc = std::allocator<std::pair<int, int> >; std::set<_Key, _Compare, _Alloc>::insert_return_type = std::_Rb_tree<std::pair<int, int>, std::pair<int, int>, std::_Identity<std::pair<int, int> >, std::less<std::pair<int, int> >, std::allocator<std::pair<int, int> > >::insert_return_type; std::set<_Key, _Compare, _Alloc>::node_type = std::_Rb_tree<std::pair<int, int>, std::pair<int, int>, std::_Identity<std::pair<int, int> >, std::less<std::pair<int, int> >, std::allocator<std::pair<int, int> > >::node_type]'
  598 |       insert(node_type&& __nh)
      |       ^~~~~~
/usr/include/c++/10/bits/stl_set.h:598:26: note:   no known conversion for argument 1 from '<brace-enclosed initializer list>' to 'std::set<std::pair<int, int> >::node_type&&' {aka 'std::_Rb_tree<std::pair<int, int>, std::pair<int, int>, std::_Identity<std::pair<int, int> >, std::less<std::pair<int, int> >, std::allocator<std::pair<int, int> > >::node_type&&'}
  598 |       insert(node_type&& __nh)
      |              ~~~~~~~~~~~~^~~~
/usr/include/c++/10/bits/stl_set.h:603:7: note: candidate: 'std::set<_Key, _Compare, _Alloc>::iterator std::set<_Key, _Compare, _Alloc>::insert(std::set<_Key, _Compare, _Alloc>::const_iterator, std::set<_Key, _Compare, _Alloc>::node_type&&) [with _Key = std::pair<int, int>; _Compare = std::less<std::pair<int, int> >; _Alloc = std::allocator<std::pair<int, int> >; std::set<_Key, _Compare, _Alloc>::iterator = std::_Rb_tree<std::pair<int, int>, std::pair<int, int>, std::_Identity<std::pair<int, int> >, std::less<std::pair<int, int> >, std::allocator<std::pair<int, int> > >::const_iterator; std::set<_Key, _Compare, _Alloc>::const_iterator = std::_Rb_tree<std::pair<int, int>, std::pair<int, int>, std::_Identity<std::pair<int, int> >, std::less<std::pair<int, int> >, std::allocator<std::pair<int, int> > >::const_iterator; std::set<_Key, _Compare, _Alloc>::node_type = std::_Rb_tree<std::pair<int, int>, std::pair<int, int>, std::_Identity<std::pair<int, int> >, std::less<std::pair<int, int> >, std::allocator<std::pair<int, int> > >::node_type]'
  603 |       insert(const_iterator __hint, node_type&& __nh)
      |       ^~~~~~
/usr/include/c++/10/bits/stl_set.h:603:7: note:   candidate expects 2 arguments, 1 provided
walk.cpp:140:28: error: no matching function for call to 'std::set<std::pair<int, int> >::insert(<brace-enclosed initializer list>)'
  140 |             a.insert({y, j});
      |                            ^
In file included from /usr/include/c++/10/set:61,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:87,
                 from walk.cpp:1:
/usr/include/c++/10/bits/stl_set.h:509:7: note: candidate: 'std::pair<typename std::_Rb_tree<_Key, _Key, std::_Identity<_Tp>, _Compare, typename __gnu_cxx::__alloc_traits<_Alloc>::rebind<_Key>::other>::const_iterator, bool> std::set<_Key, _Compare, _Alloc>::insert(const value_type&) [with _Key = std::pair<int, int>; _Compare = std::less<std::pair<int, int> >; _Alloc = std::allocator<std::pair<int, int> >; typename std::_Rb_tree<_Key, _Key, std::_Identity<_Tp>, _Compare, typename __gnu_cxx::__alloc_traits<_Alloc>::rebind<_Key>::other>::const_iterator = std::_Rb_tree<std::pair<int, int>, std::pair<int, int>, std::_Identity<std::pair<int, int> >, std::less<std::pair<int, int> >, std::allocator<std::pair<int, int> > >::const_iterator; std::set<_Key, _Compare, _Alloc>::value_type = std::pair<int, int>]'
  509 |       insert(const value_type& __x)
      |       ^~~~~~
/usr/include/c++/10/bits/stl_set.h:509:32: note:   no known conversion for argument 1 from '<brace-enclosed initializer list>' to 'const value_type&' {aka 'const std::pair<int, int>&'}
  509 |       insert(const value_type& __x)
      |              ~~~~~~~~~~~~~~~~~~^~~
/usr/include/c++/10/bits/stl_set.h:518:7: note: candidate: 'std::pair<typename std::_Rb_tree<_Key, _Key, std::_Identity<_Tp>, _Compare, typename __gnu_cxx::__alloc_traits<_Alloc>::rebind<_Key>::other>::const_iterator, bool> std::set<_Key, _Compare, _Alloc>::insert(std::set<_Key, _Compare, _Alloc>::value_type&&) [with _Key = std::pair<int, int>; _Compare = std::less<std::pair<int, int> >; _Alloc = std::allocator<std::pair<int, int> >; typename std::_Rb_tree<_Key, _Key, std::_Identity<_Tp>, _Compare, typename __gnu_cxx::__alloc_traits<_Alloc>::rebind<_Key>::other>::const_iterator = std::_Rb_tree<std::pair<int, int>, std::pair<int, int>, std::_Identity<std::pair<int, int> >, std::less<std::pair<int, int> >, std::allocator<std::pair<int, int> > >::const_iterator; std::set<_Key, _Compare, _Alloc>::value_type = std::pair<int, int>]'
  518 |       insert(value_type&& __x)
      |       ^~~~~~
/usr/include/c++/10/bits/stl_set.h:518:27: note:   no known conversion for argument 1 from '<brace-enclosed initializer list>' to 'std::set<std::pair<int, int> >::value_type&&' {aka 'std::pair<int, int>&&'}
  518 |       insert(value_type&& __x)
      |              ~~~~~~~~~~~~~^~~
/usr/include/c++/10/bits/stl_set.h:546:7: note: candidate: 'std::set<_Key, _Compare, _Alloc>::iterator std::set<_Key, _Compare, _Alloc>::insert(std::set<_Key, _Compare, _Alloc>::const_iterator, const value_type&) [with _Key = std::pair<int, int>; _Compare = std::less<std::pair<int, int> >; _Alloc = std::allocator<std::pair<int, int> >; std::set<_Key, _Compare, _Alloc>::iterator = std::_Rb_tree<std::pair<int, int>, std::pair<int, int>, std::_Identity<std::pair<int, int> >, std::less<std::pair<int, int> >, std::allocator<std::pair<int, int> > >::const_iterator; std::set<_Key, _Compare, _Alloc>::const_iterator = std::_Rb_tree<std::pair<int, int>, std::pair<int, int>, std::_Identity<std::pair<int, int> >, std::less<std::pair<int, int> >, std::allocator<std::pair<int, int> > >::const_iterator; std::set<_Key, _Compare, _Alloc>::value_type = std::pair<int, int>]'
  546 |       insert(const_iterator __position, const value_type& __x)
      |       ^~~~~~
/usr/include/c++/10/bits/stl_set.h:546:7: note:   candidate expects 2 arguments, 1 provided
/usr/include/c++/10/bits/stl_set.h:551:7: note: candidate: 'std::set<_Key, _Compare, _Alloc>::iterator std::set<_Key, _Compare, _Alloc>::insert(std::set<_Key, _Compare, _Alloc>::const_iterator, std::set<_Key, _Compare, _Alloc>::value_type&&) [with _Key = std::pair<int, int>; _Compare = std::less<std::pair<int, int> >; _Alloc = std::allocator<std::pair<int, int> >; std::set<_Key, _Compare, _Alloc>::iterator = std::_Rb_tree<std::pair<int, int>, std::pair<int, int>, std::_Identity<std::pair<int, int> >, std::less<std::pair<int, int> >, std::allocator<std::pair<int, int> > >::const_iterator; std::set<_Key, _Compare, _Alloc>::const_iterator = std::_Rb_tree<std::pair<int, int>, std::pair<int, int>, std::_Identity<std::pair<int, int> >, std::less<std::pair<int, int> >, std::allocator<std::pair<int, int> > >::const_iterator; std::set<_Key, _Compare, _Alloc>::value_type = std::pair<int, int>]'
  551 |       insert(const_iterator __position, value_type&& __x)
      |       ^~~~~~
/usr/include/c++/10/bits/stl_set.h:551:7: note:   candidate expects 2 arguments, 1 provided
/usr/include/c++/10/bits/stl_set.h:566:2: note: candidate: 'template<class _InputIterator> void std::set<_Key, _Compare, _Alloc>::insert(_InputIterator, _InputIterator) [with _InputIterator = _InputIterator; _Key = std::pair<int, int>; _Compare = std::less<std::pair<int, int> >; _Alloc = std::allocator<std::pair<int, int> >]'
  566 |  insert(_InputIterator __first, _InputIterator __last)
      |  ^~~~~~
/usr/include/c++/10/bits/stl_set.h:566:2: note:   template argument deduction/substitution failed:
walk.cpp:140:28: note:   candidate expects 2 arguments, 1 provided
  140 |             a.insert({y, j});
      |                            ^
In file included from /usr/include/c++/10/set:61,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:87,
                 from walk.cpp:1:
/usr/include/c++/10/bits/stl_set.h:578:7: note: candidate: 'void std::set<_Key, _Compare, _Alloc>::insert(std::initializer_list<_Tp>) [with _Key = std::pair<int, int>; _Compare = std::less<std::pair<int, int> >; _Alloc = std::allocator<std::pair<int, int> >]'
  578 |       insert(initializer_list<value_type> __l)
      |       ^~~~~~
/usr/include/c++/10/bits/stl_set.h:578:43: note:   no known conversion for argument 1 from '<brace-enclosed initializer list>' to 'std::initializer_list<std::pair<int, int> >'
  578 |       insert(initializer_list<value_type> __l)
      |              ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~
/usr/include/c++/10/bits/stl_set.h:598:7: note: candidate: 'std::set<_Key, _Compare, _Alloc>::i