/*
- find a node x in each component such that the max distance from x to a leaf
is minimized
- connect the x's from all the components to the x in the biggest component
- ans = max(path in one component, biggest depth + 2nd biggest depth + L, 2nd biggest depth + 3rd biggest depth + 2*L
*/
#include "dreaming.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define For(i, a, b) for(int i=a; i<b; i++)
#define ffi For(i, 0, N)
#define ffj For(j, 0, M)
#define ffa ffi ffj
#define s <<" "<<
#define c <<" : "<<
#define w cout
#define e "\n"
#define pb push_back
#define mp make_pair
#define a first
#define b second
#define int ll
const int MAXN = 100000, INF = 1000000000000000000;
//500,000,000 operations
int farund[MAXN], far2[MAXN], out, sm;
pair<int, int> far1[MAXN]; /// (value, child)
vector<int> vals;
bool vis[MAXN];
vector<pair<int, int> > adj[MAXN];
void go1(int at) {
if (vis[at]) return;
vis[at] = true;
for (auto i: adj[at]) if (!vis[i.a]) {
go1(i.a);
farund[at] = max(farund[at], i.b+farund[i.a]);
}
}
void go2(int at, int p, int d) {
if (vis[at]) return;
vis[at] = true;
for (auto i: adj[at]) if (i.a != p) {
int len = farund[i.a] + i.b;
if (len > far1[at].a) {
far2[at] = far1[at].a;
far1[at] = mp(len, i.a);
}
else if (len > far2[at]) far2[at] = len;
}
if (at != p) {
int up;
if (far1[p].b == at) up = far2[p]+d;
else up = far1[p].a + d;
if (up > far1[at].a) {
far2[at] = far1[at].a;
far1[at] = mp(up, p);
}
else if (up > far2[at]) far2[at] = up;
//w<< "up" s at c up<<e;
}
for (auto i: adj[at]) if (i.a != p) go2(i.a, at, i.b);
}
void go3(int at) {
if (vis[at]) return;
vis[at] = true;
sm = min(sm, far1[at].a);
for (auto i: adj[at]) go3(i.a);
}
int travelTime(int N, int M, int L, int A[], int B[], int T[]) {
ffj {
int a = A[j], b = B[j], d = T[j];
adj[a].emplace_back(b, d);
adj[b].emplace_back(a, d);
}
ffi go1(i);
ffi vis[i] = false;
ffi go2(i, i, 0);
//ffi w<< i c far1[i].a<<e;
ffi out = max(out, far1[i].a);
ffi vis[i] = false;
ffi if (!vis[i]) {
sm = INF;
go3(i);
vals.pb(sm);
}
while (vals.size() < 3) vals.pb(0);
sort(vals.begin(), vals.end());
reverse(vals.begin(), vals.end());
out = max(out, max(vals[0]+vals[1]+L, vals[1]+vals[2]+2*L));
return out;
}
Compilation message
/tmp/ccOYmn0N.o: In function `main':
grader.c:(.text.startup+0xa2): undefined reference to `travelTime'
collect2: error: ld returned 1 exit status
