#include <bits/stdc++.h>
#include "dreaming.h"
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pi;
typedef pair<ll, ll> pl;
typedef vector<int> vi;
typedef vector<ld> vd;
typedef vector<ll> vl;
#define pb push_back
#define f first
#define s second
namespace debug {
const int DEBUG = true;
template<class T1, class T2>
void pr(const pair<T1, T2> &x);
template<class T, size_t SZ>
void pr(const array<T, SZ> &x);
template<class T>
void pr(const vector<T> &x);
template<class T>
void pr(const set<T> &x);
template<class T1, class T2>
void pr(const map<T1, T2> &x);
template<class T>
void pr(const T &x) { if (DEBUG) cout << x; }
template<class T, class... Ts>
void pr(const T &first, const Ts &... rest) { pr(first), pr(rest...); }
template<class T1, class T2>
void pr(const pair<T1, T2> &x) { pr("{", x.f, ", ", x.s, "}"); }
template<class T>
void prIn(const T &x) {
pr("{");
bool fst = 1;
for (auto &a : x) {
pr(fst ? "" : ", ", a), fst = 0;
}
pr("}");
}
template<class T, size_t SZ>
void pr(const array<T, SZ> &x) { prIn(x); }
template<class T>
void pr(const vector<T> &x) { prIn(x); }
template<class T>
void pr(const set<T> &x) { prIn(x); }
template<class T1, class T2>
void pr(const map<T1, T2> &x) { prIn(x); }
void ps() { pr("\n"), cout << flush; }
template<class Arg, class... Args>
void ps(const Arg &first, const Args &... rest) {
pr(first, " ");
ps(rest...);
}
}
using namespace debug;
vector<pi> aL[101000];
vi visTime;
vi dist0, distD1, distD2;
bool fComp;
vi cComp;
int cTime = 0;
int intDist = 0;
void fDist(int cV, int cD, vi &dists) {
if (visTime[cV] == cTime) {
return;
}
visTime[cV] = cTime;
dists[cV] = cD;
if (fComp) {
cComp.pb(cV);
}
for (pi aE : aL[cV]) {
fDist(aE.f, cD + aE.s, dists);
}
}
int fFurthest(int cM) {
cComp.clear();
fComp = true;
cTime++;
fDist(cM, 0, dist0);
int d1 = cM;
for (int i : cComp) {
if (dist0[i] > dist0[d1]) {
d1 = i;
}
}
fComp = false;
cTime++;
fDist(d1, 0, distD1);
int d2 = cM;
for (int i : cComp) {
if (distD1[i] > distD1[d2]) {
d2 = i;
}
}
cTime++;
fDist(d2, 0, distD2);
intDist = max(intDist, distD1[d2]);
int minD = 1e9;
for (int i : cComp) {
int cFur = max(distD1[i], distD2[i]);
minD = min(minD, cFur);
}
return minD;
}
int travelTime(int N, int M, int L, int A[], int B[], int T[]) {
for (int i = 0; i < M; i++) {
aL[A[i]].pb({B[i], T[i]});
aL[B[i]].pb({A[i], T[i]});
}
visTime.resize(N);
fill(visTime.begin(), visTime.end(), -1);
visTime.resize(N);
fill(visTime.begin(), visTime.end(), -1);
dist0.resize(N);
distD1.resize(N);
distD2.resize(N);
vi furthests;
for (int i = 0; i < N; i++) {
if (visTime[i] == -1) {
furthests.pb(fFurthest(i));
}
}
sort(furthests.begin(), furthests.end());
reverse(furthests.begin(), furthests.end());
int ans = intDist;
if (furthests.size() >= 2) {
ans = max(ans, L + furthests[0] + furthests[1]);
}
if (furthests.size() >= 3) {
ans = max(ans, 2 * L + furthests[1] + furthests[2]);
}
return ans;
}
