trying this speedup

Author: lrvideckis

library/graphs/strongly_connected_components/offline_incremental_scc.hpp

@@ -15,7 +15,7 @@ vi offline_incremental_scc(vector<array<int, 2>> eds,
   int m = sz(eds);
   vi ids(n, -1), joins(m, m), idx(m), vs(n), scc_id;
   iota(all(idx), 0);
-  vector<vi> adj;
+  vector<basic_string<int>> adj;
   auto divide_and_conquer = [&](auto&& self, auto el,
                                 auto er, int tl, int tr) {
     adj.clear();

library/graphs/strongly_connected_components/scc.hpp

@@ -7,10 +7,10 @@
 //! for each edge u -> v: scc_id[u] >= scc_id[v]
 //! @time O(n + m)
 //! @space O(n)
-struct sccs {
+template <class G> struct sccs {
   int num_sccs = 0;
   vi scc_id;
-  sccs(const vector<vi>& adj): scc_id(sz(adj), -1) {
+  sccs(const G& adj) : scc_id(sz(adj), -1) {
     int n = sz(adj), timer = 1;
     vi tin(n), st;
     auto dfs = [&](auto&& self, int v) -> int {