| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 110258 | icandoit | Dreaming (IOI13_dreaming) | C++14 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include "dreaming.h"
#include <bits/stdc++.h>
#define y second
#define x first
#define ll long long int
#define pb push_back
#define pii pair<int,int>
using namespace std;
const int N=1e5+7;
vector<pair<int,int> > adj[N];
bool vis[N];
void dfs(int node,int p,int length,pii &ans){
vis[node]=1;
for(auto vertice:adj[node]){
if(vertice.x==p){
continue;
}
dfs(vertice.x,node,length+vertice.y,ans);
}
if(length>ans.y){
ans.x=node;
ans.y=length;
}
}
bool find(int s,int e,int p,vector<int> &path){
if(s==e){
return true;
}
for(int v:adj[s]){
if(v==p)continue;
if(find(v,e,u,path)){
path.push_back(v);
return true;
}
}
return false;
}
int travelTime(int N, int M, int L, int A[], int B[], int T[]) {
int n=N;
int m=M;
int l=L;
vector<int> radius;
map<pair<int,int>,int> cost;
for(int i=0; i<M; i++) {
int u=A[i];
int v=B[i];
int w=T[i];
adj[u].pb({v,w});
adj[v].pb({u,w});
cost[{u,v}]=cost[{v,u}]=w;
}
for(int i=0;i<n;i++){
if(vis[i]) continue;
pii s={-1,-1};
dfs(i,-1,0,s);
pii e={-1,-1};
dfs(s.first,-1,0,e);
int diameter=e.y;
vector<int> path;
find(s.x,e.x,path);
int sz=(int)path.size();
int rad=diameter;
int cur=diameter;
for(int j=1;j<sz;j++){
cur-=cost[{path[j],path[j-1]}];
rad=min(rad,max(diameter-cur,cur));
}
radius.push_back(rad);
}
int szz=(int)radius.size();
sort(radius.rbegin(),radius.rend());
int lol=radius[0];
if(szz>=2){
lol=max(lol,radius[0]+radius[1]+l);
}
if(szz>=3){
lol=max(lol,radius[1]+radius[2]+2*l);
}
return lol;
}