#include "dreaming.h"
#include <vector>
#include <algorithm>
#include <queue>
using namespace std;
const int INF = 2e9;
vector<pair<int, int>> adj[100005];
bool visited[100005];
vector<int> nodes;
void dfs_find_nodes(int u) {
visited[u] = true;
nodes.push_back(u);
for (auto& edge : adj[u]) {
if (!visited[edge.first]) dfs_find_nodes(edge.first);
}
}
// Eng uzoq masofani topish uchun yordamchi BFS
pair<int, int> bfs(int start, int n_limit, vector<int>& d_out) {
for (int node : nodes) d_out[node] = -1;
queue<int> q;
q.push(start);
d_out[start] = 0;
int farthest_node = start;
while (!q.empty()) {
int u = q.front(); q.pop();
if (d_out[u] > d_out[farthest_node]) farthest_node = u;
for (auto& edge : adj[u]) {
if (d_out[edge.first] == -1) {
d_out[edge.first] = d_out[u] + edge.second;
q.push(edge.first);
}
}
}
return {farthest_node, d_out[farthest_node]};
}
int travelTime(int N, int M, int L, int A[], int B[], int T[]) {
for (int i = 0; i < M; i++) {
adj[A[i]].push_back({B[i], T[i]});
adj[B[i]].push_back({A[i], T[i]});
}
vector<int> radii;
int max_diameter = 0;
vector<int> dist1(N), dist2(N);
for (int i = 0; i < N; i++) {
if (!visited[i]) {
nodes.clear();
dfs_find_nodes(i);
// Diametrni topish: 1-BFS eng chekka uchi u ni topadi
pair<int, int> u = bfs(i, N, dist1);
// 2-BFS u dan eng chekka v ni topadi
pair<int, int> v = bfs(u.first, N, dist1);
// 3-BFS v dan qaytib distlarni hisoblaydi
bfs(v.first, N, dist2);
max_diameter = max(max_diameter, v.second);
// Shu daraxtning radiusini (minimal maksimal masofa) topamiz
int min_max_dist = INF;
for (int node : nodes) {
min_max_dist = min(min_max_dist, max(dist1[node], dist2[node]));
}
radii.push_back(min_max_dist);
}
}
sort(radii.rbegin(), radii.rend());
if (radii.size() >= 2) {
max_diameter = max(max_diameter, radii[0] + L + radii[1]);
}
if (radii.size() >= 3) {
max_diameter = max(max_diameter, radii[1] + 2 * L + radii[2]);
}
return max_diameter;
}
