#include <bits/stdc++.h>
using namespace std;
int ds[2][(int)1e5];
unordered_map<int,int> adj[(int)1e5];
int vis[(int)1e5];
int ind = 0;
unordered_set<int> sets[(int)1e5];
int cp[(int)1e5];
void dfs(int i , int p, int len, int x){
sets[ind].insert(i);
vis[i] = 1;
ds[x][i] = len;
for (auto const &pair: adj[i]){
int c = pair.first; int w= pair.second;
if (c==p) continue;
dfs(c,i, len+w,x);
}
}
int travelTime(int N, int M, int L, int A[], int B[], int T[]){
for (int i=0; i<M; i++){
int a = A[i]; int b = B[i];
adj[a][b] = T[i]; adj[b][a] = T[i];
}
for (int i=0; i<N; i++){
if (vis[i]) continue;
dfs(i,i,0,0);
int a1 = i;
for (auto c: sets[ind]){
if (ds[0][c]>ds[0][a1]) a1 = c;
}
dfs(a1,a1,0,0);
int a2 = a1;
for (auto c: sets[ind]){
if (ds[0][c]>ds[0][a2]) a2 = c;
}
dfs(a2,a2,0,1);
int ans = 1e7;
for (auto c: sets[ind]){
ans = min(ans, max(ds[0][c], ds[1][c]));
}
cp[ind] = ans;
ind++;
}
if (ind == 1){
int s = 0;
for (int c=0; c<N; c++){
if (ds[0][c]>ds[0][s]) s = c;
}
return ds[0][s];
}
sort(cp, cp+ind);
return L + cp[ind-1] + cp[ind-2];
}
// int main(){
// int n = 12; int m = 8 ;
// int l = 2;
// int a[] = {0, 8, 2, 5, 5, 1, 1, 10};
// int b[] = {8, 2, 7, 11, 1, 3, 9, 6};
// int t[] = {4, 2, 4, 3, 7, 1, 5, 3};
// cout<<travelTime(n,m,l,a,b,t);
// }
Compilation message
/usr/bin/ld: /tmp/ccpkNFOo.o: in function `main':
grader.c:(.text.startup+0xd1): undefined reference to `travelTime'
collect2: error: ld returned 1 exit status
