#include <bits/stdc++.h>
#define pii pair<int, int>
#define f first
#define s second
#define up(i, a, b) for (int i = (a); i <= (b); i++)
#define pb push_back
#define int long long
using namespace std;
const int oo = 2*100000000000000000;
const int maxn = 100001;
int n, m, L;
vector<pii> a[maxn];
void in(){
cin >> n >> m >> L;
int u,v,w;
up(i, 1, m){
cin >> u >> v >> w;
u++;
v++;
a[u].pb({v, w});
a[v].pb({u, w});
}
}
int cost[maxn];
bool dd[maxn];
int dx[maxn];
int dy[maxn];
vector<int> luu;
int maxx;
void DFS(int u, int parent, int d[]){
dd[u] = 1;
luu.emplace_back(u);
for (pii x : a[u]){
int v = x.f;
int w = x.s;
if (v == parent) continue;
d[v] = d[u] + w;
DFS(v, u, d);
}
}
vector<int> R;
int minn = oo;
void find_center(int root){
DFS(root, -1, cost);
int X = max_element(cost+1, cost+n+1) - cost;
DFS(X, -1, dx);
int Y = max_element(dx+1, dx+n+1) - dx;
DFS(Y, -1, dy);
minn = oo;
for (auto x : luu){
minn = min(minn, max(dx[x], dy[x]));
}
R.push_back(minn);
for (auto x : luu){
cost[x] = dx[x] = dy[x] = 0;
}
luu.clear();
}
signed main(){
if (fopen("A.inp", "r")){
freopen ("A.inp", "r", stdin);
freopen ("A.out", "w", stdout);
}
in();
up(root, 1, n){
if (!dd[root]){
find_center(root);
}
}
int tplt = R.size();
if (tplt == 1){
cout << minn;
}
sort(R.begin(), R.end(), greater<int>());
int maxx = -oo;
if (tplt > 1){
maxx = max(maxx, R[0] + R[1] + L);
}
if (tplt > 2){
maxx = max(maxx, R[1] + R[2] + 2*L);
}
cout << maxx;
}
Compilation message
dreaming.cpp: In function 'int main()':
dreaming.cpp:71:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
71 | freopen ("A.inp", "r", stdin);
| ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~
dreaming.cpp:72:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
72 | freopen ("A.out", "w", stdout);
| ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
/usr/bin/ld: /tmp/ccXOdE01.o: in function `main':
dreaming.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/ccoYoLb1.o:grader.c:(.text.startup+0x0): first defined here
/usr/bin/ld: /tmp/ccoYoLb1.o: in function `main':
grader.c:(.text.startup+0xd1): undefined reference to `travelTime'
collect2: error: ld returned 1 exit status
