ten second time limit

.github/workflows/programming_team_code_ci.yml

@@ -27,7 +27,7 @@ jobs:
     - name: Run tests
       env:
         GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-      run: oj-verify all --tle 35 --timeout 21600
+      run: oj-verify all --tle 10 --timeout 21600
 
   check_format_lint:
     runs-on: ubuntu-latest

.verify-helper/timestamps.remote.json

@@ -6,7 +6,7 @@
 "tests/library_checker_aizu_tests/data_structures/binary_trie.test.cpp": "2024-11-17 14:04:03 -0600",
 "tests/library_checker_aizu_tests/data_structures/bit.test.cpp": "2024-12-14 19:50:29 -0600",
 "tests/library_checker_aizu_tests/data_structures/bit_inc.test.cpp": "2024-11-18 09:44:22 -0600",
-"tests/library_checker_aizu_tests/data_structures/bit_ordered_set.test.cpp": "2024-11-18 09:44:22 -0600",
+"tests/library_checker_aizu_tests/data_structures/bit_ordered_set.test.cpp": "2024-12-10 11:52:04 -0600",
 "tests/library_checker_aizu_tests/data_structures/bit_rupq.test.cpp": "2024-12-05 10:41:42 -0600",
 "tests/library_checker_aizu_tests/data_structures/bit_rurq.test.cpp": "2024-12-05 10:41:42 -0600",
 "tests/library_checker_aizu_tests/data_structures/bit_walk.test.cpp": "2024-12-14 19:50:29 -0600",
@@ -21,7 +21,7 @@
 "tests/library_checker_aizu_tests/data_structures/dsu_bipartite.test.cpp": "2024-12-14 19:50:29 -0600",
 "tests/library_checker_aizu_tests/data_structures/dsu_restorable.test.cpp": "2024-11-17 14:04:03 -0600",
 "tests/library_checker_aizu_tests/data_structures/dsu_segtree_undo_trick.test.cpp": "2024-12-14 19:50:29 -0600",
-"tests/library_checker_aizu_tests/data_structures/implicit_seg_tree.test.cpp": "2024-11-17 14:04:03 -0600",
+"tests/library_checker_aizu_tests/data_structures/implicit_seg_tree.test.cpp": "2024-12-15 09:29:23 -0600",
 "tests/library_checker_aizu_tests/data_structures/kruskal_tree_aizu.test.cpp": "2024-11-17 14:04:03 -0600",
 "tests/library_checker_aizu_tests/data_structures/kth_smallest_pst.test.cpp": "2024-12-05 10:41:42 -0600",
 "tests/library_checker_aizu_tests/data_structures/kth_smallest_wavelet_matrix.test.cpp": "2024-11-19 08:31:51 -0600",
@@ -38,40 +38,41 @@
 "tests/library_checker_aizu_tests/data_structures/persistent_seg_tree.test.cpp": "2024-12-05 10:41:42 -0600",
 "tests/library_checker_aizu_tests/data_structures/pq_ds_undo_sliding_window.test.cpp": "2024-12-05 10:41:42 -0600",
 "tests/library_checker_aizu_tests/data_structures/pq_ds_undo_with_dsu.test.cpp": "2024-12-05 10:41:42 -0600",
-"tests/library_checker_aizu_tests/data_structures/range_parallel_dsu.test.cpp": "2024-12-14 19:50:29 -0600",
-"tests/library_checker_aizu_tests/data_structures/rmq_all_methods.test.cpp": "2024-12-14 19:50:29 -0600",
-"tests/library_checker_aizu_tests/data_structures/rmq_inc.test.cpp": "2024-12-14 15:47:13 -0600",
+"tests/library_checker_aizu_tests/data_structures/range_parallel_dsu.test.cpp": "2024-12-15 12:37:34 -0600",
+"tests/library_checker_aizu_tests/data_structures/rmq_disjoint_sparse_table.test.cpp": "2024-12-15 09:26:21 -0600",
+"tests/library_checker_aizu_tests/data_structures/rmq_linear.test.cpp": "2024-12-15 12:37:34 -0600",
+"tests/library_checker_aizu_tests/data_structures/rmq_sparse_table.test.cpp": "2024-12-15 12:37:34 -0600",
+"tests/library_checker_aizu_tests/data_structures/rmq_sparse_table_inc.test.cpp": "2024-12-15 09:26:21 -0600",
 "tests/library_checker_aizu_tests/data_structures/simple_tree.test.cpp": "2024-12-14 15:47:13 -0600",
 "tests/library_checker_aizu_tests/data_structures/simple_tree_inc.test.cpp": "2024-12-14 15:47:13 -0600",
 "tests/library_checker_aizu_tests/data_structures/simple_tree_inc_line.test.cpp": "2024-12-14 15:47:13 -0600",
 "tests/library_checker_aizu_tests/data_structures/simple_tree_line.test.cpp": "2024-12-14 15:47:13 -0600",
 "tests/library_checker_aizu_tests/flow/dinic_aizu.test.cpp": "2024-11-17 14:04:03 -0600",
-"tests/library_checker_aizu_tests/flow/dinic_lib_checker.test.cpp": "2024-11-17 14:04:03 -0600",
 "tests/library_checker_aizu_tests/flow/hungarian.test.cpp": "2024-11-17 14:04:03 -0600",
 "tests/library_checker_aizu_tests/flow/min_cost_max_flow.test.cpp": "2024-12-05 10:41:42 -0600",
 "tests/library_checker_aizu_tests/graphs/biconnected_components.test.cpp": "2024-12-15 09:01:54 -0600",
 "tests/library_checker_aizu_tests/graphs/connected_components_of_complement_graph.test.cpp": "2024-12-14 19:50:29 -0600",
 "tests/library_checker_aizu_tests/graphs/dijkstra_aizu.test.cpp": "2024-12-14 19:50:29 -0600",
 "tests/library_checker_aizu_tests/graphs/dijkstra_lib_checker.test.cpp": "2024-12-14 19:50:29 -0600",
-"tests/library_checker_aizu_tests/graphs/directed_cycle.test.cpp": "2024-12-15 09:01:54 -0600",
+"tests/library_checker_aizu_tests/graphs/directed_cycle.test.cpp": "2024-12-15 12:40:15 -0600",
 "tests/library_checker_aizu_tests/graphs/enumerate_triangles.test.cpp": "2024-12-14 19:50:29 -0600",
 "tests/library_checker_aizu_tests/graphs/hopcroft_karp_aizu.test.cpp": "2024-12-14 19:50:29 -0600",
 "tests/library_checker_aizu_tests/graphs/hopcroft_karp_lib_checker.test.cpp": "2024-12-14 19:50:29 -0600",
 "tests/library_checker_aizu_tests/graphs/mst.test.cpp": "2024-11-17 14:04:03 -0600",
-"tests/library_checker_aizu_tests/graphs/offline_incremental_scc.test.cpp": "2024-12-15 09:01:54 -0600",
-"tests/library_checker_aizu_tests/graphs/strongly_connected_components_aizu.test.cpp": "2024-12-15 09:01:54 -0600",
-"tests/library_checker_aizu_tests/graphs/strongly_connected_components_lib_checker.test.cpp": "2024-12-15 09:01:54 -0600",
+"tests/library_checker_aizu_tests/graphs/offline_incremental_scc.test.cpp": "2024-12-15 12:40:15 -0600",
+"tests/library_checker_aizu_tests/graphs/strongly_connected_components_aizu.test.cpp": "2024-12-15 12:40:15 -0600",
+"tests/library_checker_aizu_tests/graphs/strongly_connected_components_lib_checker.test.cpp": "2024-12-15 12:40:15 -0600",
 "tests/library_checker_aizu_tests/graphs/two_edge_components.test.cpp": "2024-12-15 09:01:54 -0600",
-"tests/library_checker_aizu_tests/handmade_tests/count_paths_forest.test.cpp": "2024-12-14 19:50:29 -0600",
+"tests/library_checker_aizu_tests/handmade_tests/count_paths_forest.test.cpp": "2024-12-15 12:37:34 -0600",
 "tests/library_checker_aizu_tests/handmade_tests/dsu_size.test.cpp": "2024-12-14 19:50:29 -0600",
 "tests/library_checker_aizu_tests/handmade_tests/dynamic_bitset.test.cpp": "2024-11-22 10:47:44 -0600",
-"tests/library_checker_aizu_tests/handmade_tests/edge_cd_small_trees.test.cpp": "2024-12-14 18:43:21 -0600",
+"tests/library_checker_aizu_tests/handmade_tests/edge_cd_small_trees.test.cpp": "2024-12-15 12:37:34 -0600",
 "tests/library_checker_aizu_tests/handmade_tests/fib_matrix_expo.test.cpp": "2024-12-14 19:50:29 -0600",
-"tests/library_checker_aizu_tests/handmade_tests/functional_graph.test.cpp": "2024-12-14 19:50:29 -0600",
+"tests/library_checker_aizu_tests/handmade_tests/functional_graph.test.cpp": "2024-12-15 12:37:34 -0600",
 "tests/library_checker_aizu_tests/handmade_tests/lca_ladder_forest.test.cpp": "2024-12-14 19:50:29 -0600",
 "tests/library_checker_aizu_tests/handmade_tests/manacher.test.cpp": "2024-12-14 19:50:29 -0600",
 "tests/library_checker_aizu_tests/handmade_tests/merge_st_and_wavelet.test.cpp": "2024-12-14 19:50:29 -0600",
-"tests/library_checker_aizu_tests/handmade_tests/mobius.test.cpp": "2024-11-17 14:04:03 -0600",
+"tests/library_checker_aizu_tests/handmade_tests/mobius.test.cpp": "2024-12-10 12:31:07 -0600",
 "tests/library_checker_aizu_tests/handmade_tests/mod_int.test.cpp": "2024-12-14 19:50:29 -0600",
 "tests/library_checker_aizu_tests/handmade_tests/n_choose_k.test.cpp": "2024-12-14 19:50:29 -0600",
 "tests/library_checker_aizu_tests/handmade_tests/permutation_tree_small.test.cpp": "2024-12-14 15:47:13 -0600",
@@ -85,7 +86,7 @@
 "tests/library_checker_aizu_tests/loops/supermasks.test.cpp": "2024-11-17 14:04:03 -0600",
 "tests/library_checker_aizu_tests/math/binary_exponentiation_mod.test.cpp": "2024-11-17 14:04:03 -0600",
 "tests/library_checker_aizu_tests/math/binary_matrix_mult.test.cpp": "2024-11-17 14:04:03 -0600",
-"tests/library_checker_aizu_tests/math/count_paths.test.cpp": "2024-11-17 14:04:03 -0600",
+"tests/library_checker_aizu_tests/math/count_paths.test.cpp": "2024-12-15 12:37:34 -0600",
 "tests/library_checker_aizu_tests/math/derangement.test.cpp": "2024-11-17 14:04:03 -0600",
 "tests/library_checker_aizu_tests/math/matrix_determinant.test.cpp": "2024-12-14 15:47:13 -0600",
 "tests/library_checker_aizu_tests/math/matrix_mult.test.cpp": "2024-11-17 14:04:03 -0600",
@@ -100,40 +101,38 @@
 "tests/library_checker_aizu_tests/math/solve_linear_mod.test.cpp": "2024-12-14 15:47:13 -0600",
 "tests/library_checker_aizu_tests/math/tetration.test.cpp": "2024-11-17 14:04:03 -0600",
 "tests/library_checker_aizu_tests/math/totient.test.cpp": "2024-11-17 14:04:03 -0600",
-"tests/library_checker_aizu_tests/math/xor_basis.test.cpp": "2024-12-14 15:47:13 -0600",
-"tests/library_checker_aizu_tests/math/xor_basis_intersection.test.cpp": "2024-12-14 15:47:13 -0600",
+"tests/library_checker_aizu_tests/math/xor_basis.test.cpp": "2024-12-15 13:39:10 -0600",
+"tests/library_checker_aizu_tests/math/xor_basis_intersection.test.cpp": "2024-12-15 13:39:10 -0600",
 "tests/library_checker_aizu_tests/monotonic_stack_related/cartesian_binary_tree.test.cpp": "2024-12-14 19:50:29 -0600",
-"tests/library_checker_aizu_tests/monotonic_stack_related/cartesian_k_ary_tree.test.cpp": "2024-12-14 19:50:29 -0600",
-"tests/library_checker_aizu_tests/monotonic_stack_related/count_rectangles.test.cpp": "2024-12-14 19:50:29 -0600",
-"tests/library_checker_aizu_tests/monotonic_stack_related/max_rect_histogram.test.cpp": "2024-12-14 19:50:29 -0600",
+"tests/library_checker_aizu_tests/monotonic_stack_related/cartesian_k_ary_tree.test.cpp": "2024-12-15 12:37:34 -0600",
+"tests/library_checker_aizu_tests/monotonic_stack_related/count_rectangles.test.cpp": "2024-12-15 12:37:34 -0600",
+"tests/library_checker_aizu_tests/monotonic_stack_related/max_rect_histogram.test.cpp": "2024-12-15 12:37:34 -0600",
 "tests/library_checker_aizu_tests/strings/kmp.test.cpp": "2024-12-14 19:50:29 -0600",
 "tests/library_checker_aizu_tests/strings/lcp_array.test.cpp": "2024-12-14 19:50:29 -0600",
 "tests/library_checker_aizu_tests/strings/lcp_query_palindrome.test.cpp": "2024-12-14 19:50:29 -0600",
 "tests/library_checker_aizu_tests/strings/lcp_query_zfunc.test.cpp": "2024-12-14 19:50:29 -0600",
 "tests/library_checker_aizu_tests/strings/lcs_dp.test.cpp": "2024-12-05 10:41:42 -0600",
 "tests/library_checker_aizu_tests/strings/lcs_queries.test.cpp": "2024-12-14 19:50:29 -0600",
 "tests/library_checker_aizu_tests/strings/lcs_queries_merge_sort_tree.test.cpp": "2024-12-05 10:41:42 -0600",
-"tests/library_checker_aizu_tests/strings/longest_common_substring.test.cpp": "2024-12-14 19:50:29 -0600",
 "tests/library_checker_aizu_tests/strings/manacher.test.cpp": "2024-12-14 19:50:29 -0600",
 "tests/library_checker_aizu_tests/strings/multi_matching_bs.test.cpp": "2024-12-14 19:50:29 -0600",
 "tests/library_checker_aizu_tests/strings/prefix_function.test.cpp": "2024-12-14 19:50:29 -0600",
 "tests/library_checker_aizu_tests/strings/sa_cmp.test.cpp": "2024-12-14 19:50:29 -0600",
 "tests/library_checker_aizu_tests/strings/sa_sort_pairs.test.cpp": "2024-12-14 19:50:29 -0600",
 "tests/library_checker_aizu_tests/strings/single_matching_bs.test.cpp": "2024-12-14 19:50:29 -0600",
-"tests/library_checker_aizu_tests/strings/suffix_array.test.cpp": "2024-12-14 19:50:29 -0600",
+"tests/library_checker_aizu_tests/strings/suffix_array.test.cpp": "2024-12-15 12:37:34 -0600",
 "tests/library_checker_aizu_tests/strings/suffix_array_short.test.cpp": "2024-12-14 19:50:29 -0600",
 "tests/library_checker_aizu_tests/strings/trie.test.cpp": "2024-12-05 10:41:42 -0600",
 "tests/library_checker_aizu_tests/strings/wildcard_pattern_matching.test.cpp": "2024-12-14 19:50:29 -0600",
-"tests/library_checker_aizu_tests/trees/cd_jump_on_tree.test.cpp": "2024-12-14 18:43:21 -0600",
-"tests/library_checker_aizu_tests/trees/cd_lca.test.cpp": "2024-12-14 18:43:21 -0600",
-"tests/library_checker_aizu_tests/trees/count_paths_per_length.test.cpp": "2024-12-14 19:50:29 -0600",
+"tests/library_checker_aizu_tests/trees/count_paths_per_length.test.cpp": "2024-12-15 12:37:34 -0600",
 "tests/library_checker_aizu_tests/trees/edge_cd_contour_range_query.test.cpp": "2024-12-14 18:43:21 -0600",
 "tests/library_checker_aizu_tests/trees/edge_cd_contour_range_update.test.cpp": "2024-12-14 18:43:21 -0600",
 "tests/library_checker_aizu_tests/trees/edge_cd_count_paths_per_length.test.cpp": "2024-12-14 18:43:21 -0600",
 "tests/library_checker_aizu_tests/trees/edge_cd_reroot_dp.test.cpp": "2024-12-14 18:43:21 -0600",
-"tests/library_checker_aizu_tests/trees/kth_node_on_path.test.cpp": "2024-12-14 19:50:29 -0600",
-"tests/library_checker_aizu_tests/trees/ladder_decomposition.test.cpp": "2024-12-14 19:50:29 -0600",
+"tests/library_checker_aizu_tests/trees/kth_path_ladder.test.cpp": "2024-12-15 09:26:21 -0600",
+"tests/library_checker_aizu_tests/trees/kth_path_linear.test.cpp": "2024-12-15 09:26:21 -0600",
+"tests/library_checker_aizu_tests/trees/kth_path_tree_lift.test.cpp": "2024-12-15 12:37:34 -0600",
 "tests/library_checker_aizu_tests/trees/lca_all_methods_aizu.test.cpp": "2024-12-14 19:50:29 -0600",
 "tests/library_checker_aizu_tests/trees/lca_all_methods_lib_checker.test.cpp": "2024-12-14 19:50:29 -0600",
-"tests/library_checker_aizu_tests/trees/subtree_isomorphism.test.cpp": "2024-12-14 19:50:29 -0600"
+"tests/library_checker_aizu_tests/trees/subtree_isomorphism.test.cpp": "2024-12-15 12:37:34 -0600"
 }

library/graphs/strongly_connected_components/offline_incremental_scc.hpp → library/graphs/scc/offline_incremental_scc.hpp

@@ -13,26 +13,26 @@
 vi offline_incremental_scc(vector<array<int, 2>> eds,
   int n) {
   int m = sz(eds);
-  vi ids(n, -1), joins(m, m), idx(m);
+  vi ids(n, -1), joins(m, m), idx(m), vs(n), scc_id;
   iota(all(idx), 0);
+  vector<basic_string<int>> adj;
   auto divide_and_conquer = [&](auto&& self, auto el,
                               auto er, int tl, int tr) {
-    int mid = tl + (tr - tl) / 2;
-    vi vs;
-    vector<vi> adj;
+    adj.clear();
+    int mid = midpoint(tl, tr);
     for (auto it = el; it != er; it++) {
       auto& [u, v] = eds[*it];
       for (int w : {u, v}) {
         if (ids[w] != -1) continue;
-        ids[w] = sz(vs);
-        vs.push_back(w);
+        ids[w] = sz(adj);
+        vs[sz(adj)] = w;
         adj.emplace_back();
       }
       u = ids[u], v = ids[v];
       if (*it <= mid) adj[u].push_back(v);
     }
-    for (int v : vs) ids[v] = -1;
-    auto scc_id = sccs(adj).second;
+    rep(i, 0, sz(adj)) ids[vs[i]] = -1;
+    scc_id = sccs(adj).second;
     auto split = partition(el, er, [&](int i) {
       return scc_id[eds[i][0]] == scc_id[eds[i][1]];
     });
@@ -42,10 +42,6 @@ vi offline_incremental_scc(vector<array<int, 2>> eds,
       auto& [u, v] = eds[*it];
       u = scc_id[u], v = scc_id[v];
     }
-    // deallocate to avoid O(m log m) memory
-    vi().swap(vs);
-    vector<vi>().swap(adj);
-    vi().swap(scc_id);
     self(self, el, split, tl, mid);
     self(self, split, er, mid, tr);
   };

library/math/count_paths/count_paths_triangle.hpp

@@ -6,7 +6,8 @@
 vl divide_and_conquer(vl h, vl bottom) {
   {
     int start =
-      find_if(all(h), [](ll x) { return x; }) - begin(h);
+      ranges::find_if(h, [](ll x) { return x; }) -
+      begin(h);
     h.erase(begin(h), begin(h) + start);
     bottom.erase(begin(bottom), begin(bottom) + start);
   }

library/math/matrix_related/xor_basis_unordered.hpp

@@ -4,15 +4,14 @@
 //! @code
 //!   basis<int> b1;
 //!   basis<ll> b2;
-//!   basis<dynamic_bitset<>> b3;
 //! @endcode
 //! b.shrink(v) == b.shrink(b.shrink(v))
 //! for x in b.b: (bit_floor(x)&b.shrink(v))==0
 //! for 0<=i<j<sz(b.b): (bit_floor(b[i])&b[j])==0
 //! @time O(32) or O(64)
 //! @space O(32) or O(64)
 template<class T> struct basis {
-  vector<T> b;
+  basic_string<T> b;
   T shrink(T v) {
     for (T x : b) v = min(v, v ^ x);
     return v;

library/math/matrix_related/xor_basis_unordered_intersection.hpp

@@ -6,8 +6,8 @@
 template<class T>
 basis<T> intersection(const basis<T>& u,
   const basis<T>& v) {
-  vector<array<T, 2>> w(sz(u.b));
-  rep(i, 0, sz(w)) w[i] = {u.b[i], u.b[i]};
+  basic_string<array<T, 2>> w;
+  for (T e : u.b) w.push_back({e, e});
   basis<T> res;
   for (T e : v.b) {
     T s = 0;

library/math/prime_sieve/mobius.hpp

@@ -1,7 +1,7 @@
 #pragma once
 //! @time O(mx log mx)
 //! @space O(mx)
-vi mobius(1'000'005);
+vi mobius(100'005);
 mobius[1] = 1;
 rep(i, 1, sz(mobius)) for (int j = i + i; j < sz(mobius);
                            j += i) mobius[j] -= mobius[i];

library/trees/centroid_decomp_uncommon/count_paths_per_length.hpp

@@ -28,8 +28,8 @@ vector<ll> count_paths_per_length(const vector<vi>& adj) {
           swap(q, new_q);
         }
       }
-      ranges::sort(child_depths,
-        [&](auto& x, auto& y) { return sz(x) < sz(y); });
+      ranges::sort(child_depths, {},
+        [&](auto& x) { return sz(x); });
       vector total_depth(1, 1.0);
       for (auto& cnt_depth : child_depths) {
         auto prod = conv(total_depth, cnt_depth);

tests/.config/.cppcheck_suppression_list

@@ -10,7 +10,7 @@ unusedStructMember:../library/trees/ladder_decomposition/linear_kth_par.hpp:17
 unusedStructMember:../library/data_structures/dsu/dsu_bipartite.hpp:9
 unusedStructMember:../library/trees/linear_lca.hpp:15
 unusedScopedObject:../library/trees/centroid_decomp_uncommon/count_paths_per_length.hpp:12
-unusedScopedObject:library_checker_aizu_tests/cd_asserts.hpp:5
+unusedScopedObject:library_checker_aizu_tests/cd_asserts.hpp:6
 unusedScopedObject:../library/trees/centroid_decomp_uncommon/count_paths_per_node.hpp:14
 unusedScopedObject:library_checker_aizu_tests/trees/centroid_path_dist.test.cpp:29
 unusedScopedObject:../library/trees/edge_centroid_decomp_uncommon/count_paths_per_length.hpp:13
@@ -21,9 +21,10 @@ unusedScopedObject:library_checker_aizu_tests/trees/cd_jump_on_tree.test.cpp:58
 arrayIndexOutOfBoundsCond:library_checker_aizu_tests/math/linear_prime_sieve.test.cpp:17
 negativeContainerIndex:../library/strings/suffix_array/burrows_wheeler.hpp:50
 useStlAlgorithm:../kactl/content/numerical/FastFourierTransform.h:53
-useStlAlgorithm:../library/graphs/strongly_connected_components/add_edges_strongly_connected.hpp:58
+useStlAlgorithm:../library/graphs/scc/add_edges_strongly_connected.hpp:58
 useStlAlgorithm:../library/math/matrix_related/row_reduce.hpp:28
-useStlAlgorithm:../library/math/count_paths/count_paths_triangle.hpp:23
+useStlAlgorithm:../library/math/count_paths/count_paths_triangle.hpp:24
+useStlAlgorithm:../library/math/matrix_related/xor_basis_unordered_intersection.hpp:10
 shadowFunction:../kactl/content/graph/BinaryLifting.h:17
 unknownMacro:../kactl/content/graph/BinaryLifting.h:18
 constParameter:../kactl/content/graph/BinaryLifting.h:29

tests/library_checker_aizu_tests/cd_asserts.hpp

@@ -2,11 +2,14 @@
 #include "../../library/trees/centroid_decomp.hpp"
 void cd_asserts(const vector<vector<int>>& adj) {
   vector<int> decomp_size(sz(adj), -1);
+  vector<int> naive_par_decomp(sz(adj), -1);
   centroid(adj,
     [&](const vector<vector<int>>& cd_adj, int cent,
       int par_cent) -> void {
+      assert(naive_par_decomp[cent] == par_cent);
       assert(decomp_size[cent] == -1);
       auto dfs = [&](auto&& self, int u, int p) -> int {
+        naive_par_decomp[u] = cent;
         int sub_size = 1;
         for (int v : cd_adj[u])
           if (v != p) sub_size += self(self, v, u);