| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 878604 | nikd | Dreaming (IOI13_dreaming) | C++17 | 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>
#define MAXN 100001
using namespace std;
int maxpar1[MAXN];
int node1[MAXN];
int maxpar2[MAXN];
int maxlength[MAXN];
bool vis[MAXN];
int tree[MAXN];
int cont;
vector<int> mintree;
vector<pair<int, int>> adj[MAXN];
void dfs1(int v, int p){
tree[v]=cont;
vis[v]=true;
if(adj[v].size()==1){
maxpar1[v]=0;
maxpar2[v]=0;
}
else{
for (auto u : adj[v]) {
if (u.first != p){
dfs1(u.first, v);
if(maxpar1[v]<maxpar1[u.first]+u.second){
maxpar1[v]=maxpar1[u.first]+u.second;
node1[v]=u.first;
}
if(maxpar2[v]<maxpar2[u.first]+u.second){
maxpar2[v]=maxpar2[u.first]+u.second;
}
}
}
}
maxlength[v]=maxpar1[v];
}
void dfs2(int v, int p, int d){
vis[v]=true;
if(v!=p){
if(node1[p]!=v){
maxlength[v]=max(maxlength[v], maxpar1[p]+d);
}
else{
maxlength[v]=max(maxlength[v], maxpar2[p]+d);
}
}
for (auto u : adj[v]) {
if (u.first != p){
dfs2(u.first, v, u.second);
}
}
}
int travelTime(int N, int M, int L, int A[], int B[], int T[]){
for(int i = 0; i<M; i++){
adj[A[i]].push_back({B[i], T[i]});
adj[B[i]].push_back({A[i], T[i]});
}
for(int i = 0; i<N; i++){
maxpar1[i]=-1;
maxpar2[i]=-1;
maxlength[i]=-1;
vis[i]=false;
}
cont =0;
for(int i =0; i<N; i++){
if(!vis[i]){
mintree.push_back(INT_MAX);
dfs1(i,i);
cont++;
}
}
for(int i =0; i<N; i++){
dfs2(i, i, 0);
}
int maxbest1=-1;
int maxbest2=-1;
int maxbest3=-1;
for(int i =0; i<N; i++){
if(maxlength[i]<mintree[tree[i]]){
mintree[tree[i]]=maxlength[i];
if(mintree[tree[i]]>maxbest1){
maxbest1=mintree[tree[i]];
}
else if(mintree[tree[i]]>maxbest2){
maxbest2=mintree[tree[i]];
}
else if(mintree[tree[i]]>maxbest3){
maxbest3=mintree[tree[i]];
}
}
}
int sol =max(maxbest1+L+maxbest2, maxbest2+maxbest3+2*L);
return sol;
}