Inline adjacency_list iteration, don't use bump alloc in stack_union

Author: adamant-pwn

cp-algo/data_structures/stack_union.hpp

@@ -1,6 +1,5 @@
 #ifndef CP_ALGO_DATA_STRUCTURES_STACK_UNION_HPP
 #define CP_ALGO_DATA_STRUCTURES_STACK_UNION_HPP
-#include "../bump_alloc.hpp"
 #include <cstddef>
 #include <vector>
 namespace cp_algo::data_structures {

cp-algo/graph/base.hpp

@@ -25,13 +25,6 @@ namespace cp_algo::graph {
                 add_edge(u, v);
             }
         }
-        auto adjacent_generator(int v) const {
-            return [&adj = adj, v = adj.head[v]]() mutable {
-                int e = v ? adj.data[v] : -1;
-                v = adj.next[v];
-                return e;
-            };
-        }
         auto nodes_view() const {
             return std::views::iota(0, n);
         }

cp-algo/graph/cycle.hpp

@@ -9,8 +9,8 @@ namespace cp_algo::graph {
         std::vector<int> cycle;
         auto dfs = [&](auto &&self, int v, int pe) -> bool {
             state[v] = 1;
-            auto gen = g.adjacent_generator(v);
-            for(int e = gen(); ~e; e = gen()) {
+            for(int sv = g.adj.head[v]; sv; sv = g.adj.next[sv]) {
+                int e = g.adj.data[sv];
                 if(e / 2 != pe / 2) {
                     auto u = g.to[e];
                     if(state[u] == 0) {