| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 110455 | ioilolcom | 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 pnode, int dep, pair <int, int> &ret){
vis[node] = 1;
if(dep > ret.second)
ret = make_pair(node, dep);
for(auto &i : v[node])
if(i.first != pnode)
dfs(i.first, node, dep + i.second, ret);
}
bool fn(int s,int e,int p,vector<int> &path){
if(s==e) {
return true;
}
for(auto v:adj[s]) {
if(v.x==p) continue;
if(fn(v.x,e,s,path)) {
path.push_back(v.x);
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;
}
int d=0;
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;
fn(s.x,e.x,0,path);
int sz=(int)path.size();
int rad=diameter;
int cur=diameter;
d=max(d,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();
if(szz==1) return d;
sort(radius.rbegin(),radius.rend());
if(szz==2) {
// lol=max(lol,radius[0]+radius[1]+l);
return max(d,radius[0]+radius[1]+l);
}
return max(d,max(radius[0]+radius[1]+l,radius[1]+radius[2]+2*l));
}