#include <bits/stdc++.h>
//#include "dreaming.h"
using namespace std;
using ll = long long;
const int N = 1e5 + 2;
vector<array<ll, 2>> g[N];
bool vis[N];
array<ll, 2> par[N];
vector<array<ll, 2>> cost;
array<ll, 2> dfs(ll v, ll p, ll d) {
vis[v] = true;
par[v] = {p, d};
array<ll, 2> ret = {d, v};
for(auto tx : g[v]) {
ll u = tx[0], w = tx[1];
if(u == p) continue;
ret = max(ret, dfs(u, v, d + w));
}
return ret;
}
int travelTime(int N, int M, int L, int A[], int B[], int T[]) {
for(ll i = 0; i < M; i++) {
g[A[i]].push_back({B[i], T[i]});
g[B[i]].push_back({A[i], T[i]});
}
for(ll i = 0; i < N; i++) {
if(vis[i]) continue;
array<ll, 2> x = dfs(i, -1, 0);
array<ll, 2> d = dfs(x[1], -1, 0);
array<ll, 2> v = {d[1], d[0]};
array<ll, 4> ans = {d[0], d[0], 0, d[1]};
while(v[0] != -1) {
array<ll, 2> x = {v[0], par[v[0]][1]};
ans = min(ans, {abs(d[0] - 2 * x[1]), d[0] - x[1], x[1], x[0]});
v = par[v[0]];
}
//cout << ans[1] << ' ' << ans[2] << ' ' << ans[3] << '\n';
cost.push_back({d[0], ans[3]});
}
sort(cost.rbegin(), cost.rend());
for(int i = 1; i < cost.size(); i++) {
g[cost[0][1]].push_back({cost[i][1], L});
g[cost[i][1]].push_back({cost[0][1], L});
}
array<ll, 2> x = dfs(1, -1, 0);
ll answer = dfs(x[1], -1, 0)[0];
return answer;
}
Compilation message
dreaming.cpp: In function 'int travelTime(int, int, int, int*, int*, int*)':
dreaming.cpp:43:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::array<long long int, 2> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
43 | for(int i = 1; i < cost.size(); i++) {
| ~~^~~~~~~~~~~~~
/tmp/cc1IfGRM.o: In function `main':
grader.c:(.text.startup+0xc9): undefined reference to `travelTime'
collect2: error: ld returned 1 exit status
