remove cd asserts

Author: lrvideckis

library/graphs/strongly_connected_components/offline_incremental_scc.hpp

@@ -13,26 +13,25 @@
 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);
   auto divide_and_conquer = [&](auto&& self, auto el,
                                 auto er, int tl, int tr) {
-    int mid = midpoint(tl, tr);
-    vi vs;
+    int mid = midpoint(tl, tr), p = 0;
     vector<vi> adj;
     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] = p;
+        vs[p++] = 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).scc_id;
+    rep(i, 0, p) ids[vs[i]] = -1;
+    scc_id = sccs(adj).scc_id;
     auto split = partition(el, er, [&](int i) {
       return scc_id[eds[i][0]] == scc_id[eds[i][1]];
     });
@@ -43,9 +42,7 @@ vi offline_incremental_scc(vector<array<int, 2>> eds,
       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/trees/centroid_decomp_uncommon/count_paths_per_length.hpp

@@ -10,35 +10,33 @@
 vector<ll> count_paths_per_length(const vector<vi>& adj) {
   vector<ll> num_paths(sz(adj));
   centroid(adj,
-    [&](const vector<vi>& cd_adj, int cent, int) {
-      vector<vector<double>> child_depths;
-      for (int v : cd_adj[cent]) {
-        child_depths.emplace_back(1, 0.0);
-        for (queue<pii> q({{v, cent}}); !empty(q);) {
-          child_depths.back().push_back(sz(q));
-          queue<pii> new_q;
-          while (!empty(q)) {
-            auto [u, p] = q.front();
-            q.pop();
-            for (int w : cd_adj[u]) {
-              if (w == p) continue;
-              new_q.emplace(w, u);
-            }
-          }
-          swap(q, new_q);
-        }
-      }
-      ranges::sort(child_depths,
-        [&](auto& x, auto& y) { return sz(x) < sz(y); });
-      vector total_depth(1, 1.0);
-      for (auto& cnt_depth : child_depths) {
-        auto prod = conv(total_depth, cnt_depth);
-        rep(i, 1, sz(prod)) num_paths[i] +=
-          llround(prod[i]);
-        total_depth.resize(sz(cnt_depth));
-        rep(i, 1, sz(cnt_depth)) total_depth[i] +=
-          cnt_depth[i];
-      }
-    });
+           [&](const vector<vi>& cd_adj, int cent, int) {
+             vector<vector<double>> child_depths;
+             for (int v : cd_adj[cent]) {
+               child_depths.emplace_back(1, 0.0);
+               for (queue<pii> q({{v, cent}}); !empty(q);) {
+                 child_depths.back().push_back(sz(q));
+                 queue<pii> new_q;
+                 while (!empty(q)) {
+                   auto [u, p] = q.front();
+                   q.pop();
+                   for (int w : cd_adj[u]) {
+                     if (w == p) continue;
+                     new_q.emplace(w, u);
+                   }
+                 }
+                 swap(q, new_q);
+               }
+             }
+             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);
+               rep(i, 1, sz(prod)) num_paths[i] += llround(prod[i]);
+               total_depth.resize(sz(cnt_depth));
+               rep(i, 1, sz(cnt_depth)) total_depth[i] +=
+                   cnt_depth[i];
+             }
+           });
   return num_paths;
 }

tests/library_checker_aizu_tests/trees/count_paths_per_length.test.cpp

@@ -1,7 +1,6 @@
 #define PROBLEM \
   "https://judge.yosupo.jp/problem/frequency_table_of_tree_distance"
 #include "../template.hpp"
-#include "../cd_asserts.hpp"
 #include "../../../library/trees/centroid_decomp_uncommon/count_paths_per_length.hpp"
 int main() {
   cin.tie(0)->sync_with_stdio(0);
@@ -14,7 +13,6 @@ int main() {
     adj[u].push_back(v);
     adj[v].push_back(u);
   }
-  cd_asserts(adj);
   vector<ll> cnt_len = count_paths_per_length(adj);
   for (int i = 1; i < n; i++) cout << cnt_len[i] << " ";
   cout << '\n';

tests/library_checker_aizu_tests/trees/edge_cd_count_paths_per_length.test.cpp

@@ -3,8 +3,6 @@
 #include "../template.hpp"
 #include "../edge_cd_asserts.hpp"
 #include "../../../library/trees/edge_centroid_decomp_uncommon/count_paths_per_length.hpp"
-#include "../../../library/contest/random.hpp"
-#include "../../../library/trees/centroid_decomp_uncommon/count_paths_per_node.hpp"
 int main() {
   cin.tie(0)->sync_with_stdio(0);
   int n;
@@ -18,13 +16,6 @@ int main() {
   }
   { edge_cd(adj, edge_cd_asserts); }
   vector<ll> cnt_len = count_paths_per_length(adj);
-  if (n >= 2) {
-    int k = rnd(1, n - 1);
-    vector<ll> count_paths = count_paths_per_node(adj, k);
-    ll sum = accumulate(begin(count_paths), end(count_paths), 0LL);
-    assert(sum % (k + 1) == 0);
-    assert(sum / (k + 1) == cnt_len[k]);
-  }
   for (int i = 1; i < n; i++) cout << cnt_len[i] << " ";
   cout << '\n';
   return 0;