#pragma once
#include <iostream>
#include <vector>
using namespace std;
const int N=1e5+200;
vector<pair<int,int>> ma[N];
bool vis[N];
int dp_down[N][2];
int dp_up[N];
int mxx[N];
int n,m,l;
void dfs_down(int x,int p=-1)
{
vis[x]=1;
dp_down[x][0]=dp_down[x][1]=0;
for(auto [w,y]:ma[x])
{
if(y!=p)
{
dfs_down(y,x);
int cur=dp_down[y][0]+w;
if(dp_down[x][0]<cur)
{
dp_down[x][1]=dp_down[x][0];
dp_down[x][0]=cur;
}
else if(dp_down[x][1]<cur)
{
dp_down[x][1]=cur;
}
}
}
}
int vertex=-1;
int dist=2e9;
int cp=-1;
void dfs_up(int x,int p=-1)
{
mxx[x]=max(dp_up[x],dp_down[x][0]);
cp=max(cp,mxx[x]);
if(mxx[x]<dist)
{
dist=mxx[x];
vertex=x;
}
for(auto [w,y]:ma[x])
{
if(y!=p)
{
dp_up[y]=max(dp_up[y],dp_up[x]+w);
if(dp_down[x][0]==(dp_down[y][0]+w))
dp_up[y]=max(dp_up[y],dp_down[x][1]+w);
else
dp_up[y]=max(dp_up[y],dp_down[x][0]+w);
dfs_up(y,x);
}
}
}
int travelTime(int N, int M, int L, int a[], int b[], int t[])
{
n=N;
m=M;
l=L;
for(int i=0;i<m;i++)
{
ma[a[i]].push_back({t[i],b[i]});
ma[b[i]].push_back({t[i],a[i]});
}
for(int i=0;i<n;i++)
{
if(!vis[i]){
int bv=vertex;
int bd=dist;
vertex=-1;
dist=2e9;
dfs_down(i);
dfs_up(i);
if(bv!=-1)
{
ma[bv].push_back({l,vertex});
ma[vertex].push_back({l,bv});
if(dist<=bd)
{
vertex=bv;
dist=bd;
}
}
}
}
cp=-1;
dfs_down(0);
dfs_up(0);
return cp;
}
Compilation message
dreaming.cpp:1:9: warning: #pragma once in main file
1 | #pragma once
| ^~~~
/usr/bin/ld: /tmp/ccimNR5C.o: in function `main':
grader.c:(.text.startup+0xd1): undefined reference to `travelTime'
collect2: error: ld returned 1 exit status
