# |
Submission time |
Handle |
Problem |
Language |
Result |
Execution time |
Memory |
1083238 |
2024-09-02T19:05:35 Z |
Rawlat_vanak |
Race (IOI11_race) |
C++17 |
|
0 ms |
0 KB |
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define speedIO ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define mod 1000000007
#define ff first
#define ss second
#define pii pair<ll,ll>
#define pb push_back
vector<vector<pii>> graph;
vector<ll> sz,dist,rep,depth;
vector<bool> removed;
ll n,k,final;
void subtreesize(ll u, ll p){
sz[u]=1;
for(pii v:graph[u]){
if(v.ff==p) continue;
subtreesize(v.ff,u);
sz[u]+=sz[v.ff];
}
}
ll findcentroid(ll u, ll p){
for(pii v:graph[u]){
if(removed[v.ff]) continue;
if(v.ff==p) continue;
if(2*sz[v.ff]>n){
return findcentroid(v.ff,u);
}
}
return u;
}
ll dfs(ll u, ll p){
for(pii x:graph[u]){
ll v=x.ff,w=x.ss;
if(v==p) continue;
if(removed[v]) continue;
rep[v]=rep[u];
depth[v]=depth[u]+1;
dfs(v,u);
dist[v]=dist[u]+w;
}
}
void centroid_decomp(ll u, ll p){
ll ctrd=findcentroid(u,p);
//cout<<"hi "<<u<<' '<<p<<' '<<ctrd<<'\n';
dist.clear();
dist.resize(n,0);
rep.clear();
rep.resize(n);
depth.clear();
depth.resize(n,0);
for(pii v:graph[ctrd]){
if(removed[v.ff]) continue;
rep[v.ff]=v.ff;
}
dfs(ctrd,-1);
vector<ll> values(k+1,1e7);
for(ll i=0;i<n;i++){
if(removed[i]) continue;
if(dist[i]==0 or depth[i]==0 or dist[i]>k) continue;
values[dist[i]]=min(values[dist[i]],depth[i]);
}
ll ans=1e7;
values[0]=0;
for(ll i=0;i<=k;i++){
if(values[i]==1e7) continue;
if(values[k-i]!=1e7){
ans=min(ans,values[i]+values[k-i]);
}
}
final=min(final,ans);
removed[ctrd]=true;
for(pii v:graph[ctrd]){
if(removed[v.ff]) continue;
centroid_decomp(v.ff,ctrd);
}
}
int best_path(int N, int K, vector<vector<int>> h, vector<int> l){
n=N,k=K;
graph.clear();
graph.resize(n);
sz.clear();
sz.resize(n);
removed.clear();
removed.resize(n);
dist.clear();
dist.resize(n);
for(ll i=0;i<n-1;i++){
graph[h[i][0]].pb({h[i][1],l[i]});
graph[h[i][1]].pb({h[i][0],l[i]});
}
final=1e7;
subtreesize(0,-1);
centroid_decomp(0,-1);
if(final==1e7){
return -1;
}else{
return final;
}
}
Compilation message
race.cpp: In function 'long long int dfs(long long int, long long int)':
race.cpp:48:1: warning: no return statement in function returning non-void [-Wreturn-type]
48 | }
| ^
/usr/bin/ld: /tmp/cc4ToUJs.o: in function `main':
grader.cpp:(.text.startup+0x28): undefined reference to `best_path(int, int, int (*) [2], int*)'
collect2: error: ld returned 1 exit status