#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
int n, m, k;
vector<pair<int, int> > link[100002];
int DP[100002], DP2[100002];
bool visited[100002];
int ans;
int minVal;
vector<int> vec;
void dfs(int x){
visited[x] = 1;
for(auto y: link[x]){
if(visited[y.first]) continue;
dfs(y.first);
int tmp1 = DP[y.first] + y.second;
int tmp2 = DP2[y.first] + y.second;
if(DP2[x] < tmp1) DP2[x] = tmp1;
if(DP2[x] > DP[x]) swap(DP[x], DP2[x]);
if(DP2[x] < tmp2) DP2[x] = tmp2;
}
if(DP[x] < 0) DP[x] = 0;
ans = max(ans, DP[x] + DP2[x]);
visited[x] = 0;
}
void dfs2(int x, int fromUp){
visited[x] = 1;
minVal = min(minVal, max(fromUp, DP[x]));
for(auto y: link[x]){
if(visited[y.first]) continue;
dfs2(y.first, max(fromUp, (DP[x] == DP[y.first] + y.second) ? DP2[x] : DP[x]) + y.second);
}
}
int travelTime(int _n, int _m, int _k, int x[], int y[], int z[]){
n = _n, m = _m, k = _k;
for(int i=0; i<n; i++) DP[i] = DP2[i] = -1e9;
for(int i=0; i<m; i++){
link[x[i]].push_back(make_pair(y[i], z[i]));
link[y[i]].push_back(make_pair(x[i], z[i]));
}
for(int i=0; i<n; i++){
if(!visited[i]){
minVal = INT_MAX;
dfs(i);
dfs2(i, 0);
vec.push_back(minVal);
}
}
sort(vec.rbegin(), vec.rend());
if(vec.size() >= 2) ans = max(ans, vec[0] + k + vec[1]);
if(vec.size() >= 3) ans = max(ans, vec[1] + k + k + vec[2]);
return ans;
}
Compilation message
/tmp/ccV8i3gd.o: In function `main':
grader.c:(.text.startup+0xc9): undefined reference to `travelTime'
collect2: error: ld returned 1 exit status
