# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
110465 | 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 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 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;
}
map<pair<int,int> ,int>cost;
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++) {
adj[A[i]].push_back(make_pair(B[i], T[i]));
adj[B[i]].push_back(make_pair(A[i], T[i]));
cost[make_pair(A[i], B[i])] = cost[make_pair(B[i], A[i])] = T[i];
}
int ans = 0;
vector <int> a;
for(int i = 0; i < N; i++) {
if(vis[i]) continue;
pair <int, int> f = make_pair(-1, -1);
dfs(i, -1, 0, f);
pair <int, int> s = make_pair(-1, -1);
dfs(f.first, -1, 0, s);
ans = max(ans, s.second);
//path.clear();
vector<int> path;
fn(f.first, s.first,-1,path);
path.push_back(f.first);
int c = s.second;
int cur = s.second;
for(int j = 1; j < path.size(); j++) {
cur -= cost[make_pair(path[j], path[j - 1])];
c = min(c, max(cur, s.second - cur));
}
a.push_back(c);
}
sort(a.rbegin(), a.rend());
if(a.size() > 1)
ans = max(ans, a[0] + a[1] + L);
if(a.size() > 2)
ans = max(ans, a[1] + a[2] + 2 * L);
return ans;
}