#include "simurgh.h"
#include <bits/stdc++.h>
using namespace std;
static int status[300005];
static vector<pair<int, int>> adj[505];
static int depth[505], parent_node[505], parent_edge[505];
static bool visited[505];
static vector<int> tree_edges;
struct DSU {
vector<int> p;
DSU(int n) { p.resize(n); iota(p.begin(), p.end(), 0); }
int find(int i) { return (p[i] == i) ? i : (p[i] = find(p[i])); }
bool unite(int i, int j) {
int root_i = find(i), root_j = find(j);
if (root_i != root_j) { p[root_i] = root_j; return true; }
return false;
}
};
void dfs(int u, int p, int d) {
visited[u] = true;
depth[u] = d;
for (auto &edge : adj[u]) {
int v = edge.first, id = edge.second;
if (v == p) continue;
if (!visited[v]) {
parent_node[v] = u;
parent_edge[v] = id;
tree_edges.push_back(id);
dfs(v, u, d + 1);
}
}
}
void identify_initial_tree(int n, const vector<int>& u, const vector<int>& v) {
for (int i = 0; i < u.size(); i++) {
if (status[i] != -1) continue;
bool is_in_tree = false;
for (int te : tree_edges) if (te == i) is_in_tree = true;
if (is_in_tree) continue;
vector<int> cycle;
int x = u[i], y = v[i];
if (depth[x] < depth[y]) swap(x, y);
while (depth[x] > depth[y]) {
cycle.push_back(parent_edge[x]);
x = parent_node[x];
}
while (x != y) {
cycle.push_back(parent_edge[x]);
cycle.push_back(parent_edge[y]);
x = parent_node[x]; y = parent_node[y];
}
cycle.push_back(i);
int known_edge = -1;
for (int ce : cycle) if (status[ce] != -1) known_edge = ce;
int st = 0;
if (known_edge != -1) st = status[known_edge];
vector<int> query_results(cycle.size());
int max_val = -1, min_val = 1e9;
for (int j = 0; j < cycle.size(); j++) {
if (known_edge != -1 && status[cycle[j]] != -1 && cycle[j] != known_edge) {
query_results[j] = -2; continue;
}
vector<int> q;
for (int te : tree_edges) {
bool in_cycle = false;
for (int ce : cycle) if (ce == te) in_cycle = true;
if (!in_cycle) q.push_back(te);
}
for (int k = 0; k < cycle.size(); k++) if (k != j) q.push_back(cycle[k]);
query_results[j] = count_common_roads(q);
max_val = max(max_val, query_results[j]);
min_val = min(min_val, query_results[j]);
}
for (int j = 0; j < cycle.size(); j++) {
if (query_results[j] == -2) continue;
if (max_val == min_val) status[cycle[j]] = st;
else status[cycle[j]] = (query_results[j] == min_val ? 1 : 0);
}
}
for (int te : tree_edges) if (status[te] == -1) status[te] = 1;
}
vector<int> find_roads(int n, vector<int> u, vector<int> v) {
int m = u.size();
for (int i = 0; i < m; i++) {
adj[u[i]].push_back({v[i], i});
adj[v[i]].push_back({u[i], i});
status[i] = -1;
}
dfs(0, -1, 0);
identify_initial_tree(n, u, v);
for (int i = 0; i < n; i++) {
vector<int> candidates;
for (auto &edge : adj[i]) {
int id = edge.second;
if (i < (u[id] == i ? v[id] : u[id]) && status[id] == -1) {
candidates.push_back(id);
}
}
auto solve = [&](auto self, vector<int> cur_candidates) -> void {
if (cur_candidates.empty()) return;
DSU dsu(n);
vector<int> base_q;
for (int id : cur_candidates) dsu.unite(u[id], v[id]);
int royal_in_tree = 0;
for (int te : tree_edges) {
if (dsu.unite(u[te], v[te])) {
base_q.push_back(te);
if (status[te] == 1) royal_in_tree++;
}
}
vector<int> final_q = base_q;
for (int id : cur_candidates) final_q.push_back(id);
int total_royal = count_common_roads(final_q);
int royal_in_candidates = total_royal - royal_in_tree;
if (royal_in_candidates == 0) {
for (int id : cur_candidates) status[id] = 0;
} else if (cur_candidates.size() == royal_in_candidates) {
for (int id : cur_candidates) status[id] = 1;
} else {
int mid = cur_candidates.size() / 2;
vector<int> left(cur_candidates.begin(), cur_candidates.begin() + mid);
vector<int> right(cur_candidates.begin() + mid, cur_candidates.end());
self(self, left);
self(self, right);
}
};
solve(solve, candidates);
}
vector<int> res;
for (int i = 0; i < m; i++) if (status[i] == 1) res.push_back(i);
return res;
}
