// V T AN
#include <bits/stdc++.h>
#define Task "dreaming"
#define F first
#define S second
#define pb push_back
using namespace std;
const int maxn = 100005;
int n, m, l;
vector<pair<int, int> > ke[maxn];
int dd[maxn], tr[maxn], cnt;
vector<int> tplt[maxn];
long long ans[maxn], d[maxn], Max = -1, pos = -1, Spe;
void DFS_tplt(int u) {
for(auto p : ke[u]) {
int v = p.F, w = p.S;
if(dd[v]) continue;
dd[v] = 1;
tplt[cnt].pb(v);
d[v] = max(d[v], d[u] + w);
DFS_tplt(v);
}
}
void DFS(int u, int par) {
for(auto p : ke[u]) {
int v = p.F, w = p.S;
if(v == par) continue;
d[v] = max(d[v], d[u] + w);
tr[v] = u;
DFS(v, u);
}
}
void Center_node(int s) {
int mx = -1, be = -1;
tplt[++cnt].pb(s);
dd[s] = 1;
DFS_tplt(s);
if(tplt[cnt].size() == 1) {
ans[cnt] = 0;
return;
}
for(auto i : tplt[cnt]) {
if(d[i] > mx) mx = d[i], be = i;
}
for(auto x : tplt[cnt]) d[x] = 0;
DFS(be, be);
int mx2 = -1, en = -1;
for(auto i : tplt[cnt]) {
if(d[i] > mx2) mx2 = d[i], en = i;
}
ans[cnt] = 1e18;
int u = en;
Spe = max(Spe, d[en]);
while(u != be) {
ans[cnt] = min(ans[cnt], max(d[u], d[en] - d[u]));
u = tr[u];
}
}
int main(){
ios_base::sync_with_stdio(0);
cout.tie(0); cin.tie(0);
if(fopen(Task".inp", "r")){
freopen(Task".inp", "r", stdin);
freopen(Task".out", "w", stdout);
}
cin >> n >> m >> l;
for(int i = 1; i <= m; ++ i) {
int u, v, w;
cin >> u >> v >> w;
++ u, ++ v;
ke[u].pb({v, w});
ke[v].pb({u, w});
}
for(int i = 1; i <= n; ++ i) if(!dd[i]){
Center_node(i);
}
long long res = Spe;
sort(ans + 1, ans + cnt + 1, greater<int> ());
for(int i = 2; i <= n; ++ i) {
res = max(res, ans[i] + ans[1] + l);
if(i < cnt) res = max(res, ans[i] + ans[i + 1] + l * 2);
}
cout << res;
}
// CHY_AKAV
Compilation message
dreaming.cpp: In function 'int main()':
dreaming.cpp:70:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
70 | freopen(Task".inp", "r", stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
dreaming.cpp:71:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
71 | freopen(Task".out", "w", stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
/tmp/cczn80pt.o: In function `main':
dreaming.cpp:(.text.startup+0x0): multiple definition of `main'
/tmp/cc5B0ymm.o:grader.c:(.text.startup+0x0): first defined here
/tmp/cc5B0ymm.o: In function `main':
grader.c:(.text.startup+0xc9): undefined reference to `travelTime'
collect2: error: ld returned 1 exit status
