#include <bits/stdc++.h>
#include "dreaming.h"
using namespace std;
vector<int> a, b, w;
vector<vector<int> > adj;
map<pair<int,int>,int> myMap;
vector<bool> hasVisited;
vector<int> parent;
int find_farthest_node (int x, bool undo) {
queue<pair<int,int> > q;
q.push(make_pair(x, 0));
hasVisited[x] = true;
parent[x] = -1;
vector<int> nodes;
vector<pair<int,int> > vec;
while (!q.empty()) {
pair<int,int> p = q.front();
nodes.push_back(p.first);
vec.push_back(make_pair(p.second, p.first));
q.pop();
for (int j: adj[p.first]) {
if (!hasVisited[j]) {
q.push(make_pair(j, p.second + myMap[make_pair(j, p.first)]));
parent[j] = p.first;
hasVisited[j] = true;
}
}
}
sort(vec.begin(), vec.end());
reverse(vec.begin(), vec.end());
if (undo) {
for (int j: nodes) {
hasVisited[j] = false;
}
}
return vec[0].second;
}
int travelTime (int N, int M, int L, int A[], int B[], int W[]) {
a.resize(M), b.resize(M), w.resize(M), adj.resize(N), parent.resize(N);
for (int i = 0; i < M; i++) {
a[i] = A[i] - 1, b[i] = B[i] - 1, w[i] = W[i];
myMap[make_pair(a[i], b[i])] = w[i];
myMap[make_pair(b[i], a[i])] = w[i];
adj[a[i]].push_back(b[i]), adj[b[i]].push_back(a[i]);
}
return 0;
hasVisited.assign(N, false);
vector<int> paths;
for (int i = 0; i < N; i++) {
if (!hasVisited[i]) {
int x = find_farthest_node(i, true);
int y = find_farthest_node(x, false);
//x and y are endpoints of the diameter
vector<int> nodes;
int val = y;
while (val != -1) {
nodes.push_back(val);
val = parent[val];
}
int sum = 0;
for (int j = 1; j < (int) nodes.size(); j++) {
sum += myMap[make_pair(nodes[j], nodes[j - 1])];
}
int a = 0;
int myMin = INT_MAX;
for (int j = 1; j < (int)nodes.size(); j++) {
a += myMap[make_pair(nodes[j], nodes[j - 1])];
myMin = min(myMin, max(a, sum - a));
}
paths.push_back(myMin);
}
}
sort(paths.begin(), paths.end());
if (paths.size() == 1) {
return paths[0];
} else {
return paths.back() + paths[paths.size() - 2];
}
}
