nits

Author: lrvideckis

library/data_structures_[l,r)/uncommon/priority_queue_of_updates.hpp

@@ -3,24 +3,28 @@
 //! @code
 //!   RollbackUF uf(n);
 //!   vector<int> hist;
-//!   pq_updates pq([&](auto upd) {
+//!   pq_updates pq([&](H& upd) {
 //!     hist.push_back(uf.time());
 //!     uf.join(upd.first, upd.second);
 //!   }, [&]() {
 //!     uf.rollback(hist.back());
 //!     hist.pop_back();
-//!   }, pair<int, int>{});
+//!   });
 //!   pq.push(pri, {u, v});
 //! @endcode
 //! @time O(n log n)
 //! @space O(n)
-template<class F, class G, class H> struct pq_updates {
-  F update;
+using H = pii;
+template<class F, class G> struct pq_updates {
+  F upd;
   G undo;
   vector<pair<multimap<int, int>::iterator, H>> st, buf;
   multimap<int, int> mp;
-  pq_updates(F update, G undo, H):
-    update(update), undo(undo) {}
+  pq_updates(F upd, G undo): upd(upd), undo(undo) {}
+  void push(int pri, H upd_params) {
+    upd(upd_params);
+    st.emplace_back(mp.emplace(pri, sz(st)), upd_params);
+  }
   void pop() {
     buf.clear();
     int t = sz(st) - 1;
@@ -37,12 +41,8 @@ template<class F, class G, class H> struct pq_updates {
     st.pop_back();
     mp.erase(buf[0].first);
     rep(i, t, sz(st)) {
-      update(st[i].second);
+      upd(st[i].second);
       st[i].first->second = i;
     }
   }
-  void push(int pri, H upd_params) {
-    update(upd_params);
-    st.emplace_back(mp.emplace(pri, sz(st)), upd_params);
-  }
 };

tests/library_checker_aizu_tests/data_structures/pq_ds_undo_sliding_window.test.cpp

@@ -20,19 +20,14 @@ int main() {
   cin >> n >> l;
   vi arr(n);
   rep(i, 0, n) cin >> arr[i];
-  vector<int> updates;
   stack_with_get_max stm;
-  pq_updates pq([&](int id) { stm.join(updates[id]); },
-    [&]() { stm.undo(); }, int{});
+  pq_updates pq([&](pii id) { stm.join(id.first); },
+    [&]() { stm.undo(); });
   int pri = (n - l) / 2;
-  rep(i, 0, l) {
-    updates.push_back(arr[i]);
-    pq.push(pri--, size(updates) - 1);
-  }
+  rep(i, 0, l) { pq.push(pri--, {arr[i], arr[i]}); }
   cout << stm.get_max();
   rep(i, l, n) {
-    updates.push_back(arr[i]);
-    pq.push(pri--, size(updates) - 1);
+    pq.push(pri--, {arr[i], arr[i]});
     pq.pop();
     cout << " " << stm.get_max();
   }

tests/library_checker_aizu_tests/handmade_tests/pq_updates.test.cpp

@@ -7,12 +7,12 @@ int main() {
   for (int max_capacity = 1; max_capacity <= 50;
     max_capacity++) {
     rep(pattern, 0, 5) {
-      vi ds_history;
-      auto update = [&](int id) {
+      vector<pii> ds_history;
+      auto update = [&](pii id) {
         ds_history.push_back(id);
       };
       auto undo = [&]() { ds_history.pop_back(); };
-      pq_updates solver(update, undo, int{});
+      pq_updates solver(update, undo);
       map<pair<int, int>, int> naive_mp;
       int upd_id_counter = 0;
       rep(op, 0, 200) {
@@ -28,19 +28,19 @@ int main() {
           else if (pattern == 3)
             pri = (op % 2 == 0) ? 1 : 2;
           else pri = rnd(1, 100);
-          solver.push(pri, upd_id);
+          solver.push(pri, {upd_id, upd_id});
           naive_mp[{pri, upd_id}] = upd_id;
         } else {
           solver.pop();
           auto max_it = prev(end(naive_mp));
           naive_mp.erase(max_it);
         }
-        vi active_ds = ds_history;
+        vector<pii> active_ds = ds_history;
         sort(all(active_ds));
-        vi active_naive(sz(naive_mp));
+        vector<pii> active_naive(sz(naive_mp));
         int i = 0;
         for (auto [key, id] : naive_mp)
-          active_naive[i++] = id;
+          active_naive[i++] = {id, id};
         sort(all(active_naive));
         assert(active_ds == active_naive);
       }