| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 997192 | codefox | 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 <bits/stdc++.h>
#include "dreaming.h"
using namespace std;
#define pii pair<int, int>
vector<int> depth;
vector<vector<pii>> graph;
vector<int> vis;
vector<int> vis2;
vector<int> nums;
void dfs(int i, int d)
{
if(vis[i]) return;
vis[i] = 1;
nums.push_back(i);
depth[i] = d;
for (pii ele:graph[i]) dfs(ele.second, ele.first+d);
}
int travelTime(int N, int M, int L, int A[], int B[], int T[])
{
depth.assign(N, 1e9);
graph.assign(N, vector<pii>());
vis.assign(N, 0);
vis2.assign(N, 0);
vector<int> ind(N, 0);
for (int i = 0; i < M; i++)
{
graph[A[i]].push_back({B[i], T[i]});
graph[B[i]].push_back({A[i], T[i]});
ind[A[i]]++;
ind[B[i]]++;
}
int sol = 0;
vector<int> nodes;
vector<int> md(N, 0);
for (int i = 0; i < N; i++)
{
if (vis[i]) continue;
nums.clear();
dfs(i, 0);
int mx = 0;
priority_queue<pii, vector<pii>, greater<pii>> pq;
for (int ele:nums) if (ind[ele]==1) pq.push({0, ele});
while(pq.size())
{
int j, d;
tie(d, j) = pq.top();
pq.pop();
mx = max(mx, d);
if (vis2[j]) continue;
vis2[j] = 1;
for (pii ele:graph[j])
{
md[ele.first] = max(md[ele.first], ele.second+d);
ind[ele.first]--;
if (ind[ele.first]==1) pq.push({md[ele], ele.first});
}
}
int mmx = 0;
int emx = 0;
for (int ele:nums)
{
if (depth[ele]>mmx)
{
mmx = depth[ele];
emx = ele;
}
vis[ele] = 0;
}
nums.clear();
dfs(emx, 0);
for (int ele:nums)
{
mmx = max(mmx, depth[ele]);
}
nodes.push_back(mx);
sol = max(sol, mmx);
}
sort(nodes.begin(), nodes.end());
if (nodes.size()==2) sol = max(sol, nodes[0]+nodes[1]+L);
else if (nodes.size()>2) sol = max(sol, max(nodes[nodes.size()-2]+nodes[nodes.size()-3]+2*L, nodes[nodes.size()-2]+nodes.back()+L));
return sol;
}