reorg of trees folder (#154)

* initial reorg

* [auto-verifier] verify commit 63c5a61

* move include so it works on main branch

* compile fixes

* format now

* fix

* more fixes

* remove include

* fix cpp check

---------

Co-authored-by: GitHub <[email protected]>

Author: lrvideckis

.verify-helper/timestamps.remote.json

@@ -67,7 +67,6 @@
 "tests/library_checker_aizu_tests/graphs/strongly_connected_components_aizu.test.cpp": "2025-08-04 17:01:28 -0600",
 "tests/library_checker_aizu_tests/graphs/strongly_connected_components_lib_checker.test.cpp": "2025-08-04 17:01:28 -0600",
 "tests/library_checker_aizu_tests/graphs/two_edge_components.test.cpp": "2025-08-04 17:01:28 -0600",
-"tests/library_checker_aizu_tests/handmade_tests/count_paths.test.cpp": "2025-08-05 15:52:46 -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/edge_cd_small_trees.test.cpp": "2025-04-27 21:47:37 -0600",
 "tests/library_checker_aizu_tests/handmade_tests/fib_matrix_expo.test.cpp": "2024-12-14 19:50:29 -0600",
@@ -126,15 +125,4 @@
 "tests/library_checker_aizu_tests/strings/suffix_array_short.test.cpp": "2025-08-05 19:19:23 -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": "2025-08-05 19:19:23 -0600",
-"tests/library_checker_aizu_tests/trees/count_paths_per_length.test.cpp": "2025-08-05 15:52:46 -0600",
-"tests/library_checker_aizu_tests/trees/edge_cd_contour_range_query.test.cpp": "2025-04-27 21:47:37 -0600",
-"tests/library_checker_aizu_tests/trees/edge_cd_contour_range_update.test.cpp": "2025-04-27 21:47:37 -0600",
-"tests/library_checker_aizu_tests/trees/edge_cd_count_paths_per_length.test.cpp": "2025-04-27 21:47:37 -0600",
-"tests/library_checker_aizu_tests/trees/edge_cd_reroot_dp.test.cpp": "2025-04-27 21:47:37 -0600",
-"tests/library_checker_aizu_tests/trees/kth_path_ladder.test.cpp": "2025-08-06 11:58:12 -0600",
-"tests/library_checker_aizu_tests/trees/kth_path_linear.test.cpp": "2025-08-06 11:58:12 -0600",
-"tests/library_checker_aizu_tests/trees/kth_path_tree_lift.test.cpp": "2025-08-05 15:52:46 -0600",
-"tests/library_checker_aizu_tests/trees/lca_all_methods_aizu.test.cpp": "2025-08-06 09:59:41 -0600",
-"tests/library_checker_aizu_tests/trees/lca_all_methods_lib_checker.test.cpp": "2025-08-06 09:59:41 -0600",
-"tests/library_checker_aizu_tests/trees/subtree_isomorphism.test.cpp": "2025-08-05 18:22:08 -0600"
 }

library/trees/centroid_decomp_uncommon/count_paths_per_length.hpp

@@ -1,4 +1,4 @@
 //! returns 1 if v is in u's subtree
 bool in_subtree(int u, int v) {
-  return in[u] <= in[v] && in[v] < in[u] + siz[u];
+  return tin[u] <= tin[v] && tin[v] < tin[u] + siz[u];
 }

library/trees/extra_members/dist_edges.hpp renamed to library/trees/extra_members/dist.hpp

@@ -5,6 +5,7 @@
 //! @space O(1)
 int next_on_path(int u, int v) {
   assert(u != v);
-  return in_subtree(u, v) ? rmq.query(in[u] + 1, in[v] + 1)
-                          : p[u];
+  return in_subtree(u, v)
+    ? rmq.query(tin[u] + 1, tin[v] + 1)
+    : p[u];
 }

library/trees/extra_members/in_subtree.hpp

@@ -1,4 +1,3 @@
-#include "../../monotonic_stack/monotonic_stack.hpp"
 //! https://github.com/kth-competitive-programming/kactl/blob/main/content/graph/CompressTree.h
 //! @code
 //!   vector<vi> adj(n);
@@ -11,7 +10,7 @@
 //! @time O(|subset| log |subset|)
 //! @space O(|subset|)
 array<vi, 2> compress_tree(vi subset) {
-  auto proj = [&](int v) { return in[v]; };
+  auto proj = [&](int v) { return tin[v]; };
   ranges::sort(subset, {}, proj);
   int len = sz(subset);
   rep(i, 1, len)

library/trees/lca_rmq/next_on_path.hpp renamed to library/trees/extra_members/next_on_path.hpp

@@ -1,5 +1,6 @@
 #pragma once
-#include "../../data_structures/rmq.hpp"
+#include "../monotonic_stack/monotonic_stack.hpp"
+#include "../data_structures/rmq.hpp"
 //! https://github.com/kth-competitive-programming/kactl/blob/main/content/graph/LCA.h
 //! @code
 //!   {
@@ -14,13 +15,13 @@
 // NOLINTNEXTLINE(readability-identifier-naming)
 struct LCA {
   int n;
-  vi in, siz, d, p;
+  vi tin, siz, d, p;
   RMQ<int, function<int(int, int)>> rmq = {{}, NULL};
   LCA(const auto& adj):
-    n(sz(adj)), in(n), siz(n, 1), d(n), p(n) {
+    n(sz(adj)), tin(n), siz(n, 1), d(n), p(n) {
     vi order;
     auto dfs = [&](auto&& self, int v) -> void {
-      in[v] = sz(order), order.push_back(v);
+      tin[v] = sz(order), order.push_back(v);
       for (int u : adj[v])
         if (u != p[v])
           d[u] = d[p[u] = v] + 1, self(self, u),
@@ -32,12 +33,12 @@ struct LCA {
   }
   int lca(int u, int v) {
     if (u == v) return u;
-    auto [x, y] = minmax(in[u], in[v]);
+    auto [x, y] = minmax(tin[u], tin[v]);
     return p[rmq.query(x + 1, y + 1)];
   }
-#include "../extra_members/dist_edges.hpp"
-#include "../extra_members/in_subtree.hpp"
-#include "../extra_members/on_path.hpp"
-#include "next_on_path.hpp"
-#include "../extra_members/compress_tree.hpp"
+#include "extra_members/dist.hpp"
+#include "extra_members/in_subtree.hpp"
+#include "extra_members/on_path.hpp"
+#include "extra_members/next_on_path.hpp"
+#include "extra_members/virtual_tree.hpp"
 };

library/trees/extra_members/compress_tree.hpp renamed to library/trees/extra_members/virtual_tree.hpp

@@ -41,5 +41,5 @@ struct linear_lca {
     }
     return d[u] < d[v] ? u : v;
   }
-#include "extra_members/dist_edges.hpp"
+#include "extra_members/dist.hpp"
 };

library/trees/lca_rmq/lca_rmq.hpp renamed to library/trees/lca_rmq.hpp

@@ -37,5 +37,5 @@ struct tree_lift {
       else u = p[u], v = p[v];
     return u;
   }
-#include "../extra_members/dist_edges.hpp"
+#include "extra_members/dist.hpp"
 };