| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 585394 | MrDeboo | Race (IOI11_race) | 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 "race.h"
#include <bits/stdc++.h>
using namespace std;
vector<pair<int,int>>vct[500000];
pair<pair<long long,long long>,map<long long,long long>>pr[500000];
long long ans=LONG_LONG_MAX,k;
vector<int>viss(500000);
int cnt=0;
void dfs(int in){
cnt++;
assert(!viss[in]);
viss[in]=1;
if(vct[in].empty()){
pr[in].second[0]=0;
return;
}
for(auto &i:vct[in])dfs(i.first);
int f=0,g=0;
for(int i=0;i<vct[in].size();i++){
if(pr[vct[in][i].first].second.size()>f){
f=pr[vct[in][i].first].second.size();
g=i;
}
}
swap(pr[in],pr[vct[in][g].first]);
pr[in].first.first+=vct[in][g].second;
pr[in].first.second++;
if(!pr[in].second.count(-pr[in].first.first))pr[in].second[-pr[in].first.first]=-pr[in].first.second;
else pr[in].second[-pr[in].first.first]=min(pr[in].second[-pr[in].first.first],-pr[in].first.second);
if(pr[in].second.count(k-pr[in].first.first)){
ans=min(ans,(long long)pr[in].second[k-pr[in].first.first]+pr[in].first.second);
}
for(int i=0;i<vct[in].size();i++){
if(i==g)continue;
vector<pair<int,int>>V;
for(auto &w:pr[vct[in][i].first].second){
long long a=w.first+pr[vct[in][i].first].first.first+vct[in][i].second,b=w.second+pr[vct[in][i].first].first.second+1;
long long G=k-a-pr[in].first.first;
if(pr[in].second.count(G)){
ans=min(ans,(long long)pr[in].second[G]+pr[in].first.second+b);
}
a-=pr[in].first.first,b-=pr[in].first.second;
V.push_back({a,b});
}
for(auto &w:V){
if(!pr[in].second.count(w.first))pr[in].second[w.first]=w.second;
else pr[in].second[w.first]=min(pr[in].second[w.first],w.second);
}
}
}
int best_path(int n, int K, int h[][2], int l[]){
k=K;
vector<pair<int,int>>vec[n];
for(int i=0;i<n-1;i++){
vec[h[i][0]].push_back({h[i][1],l[i]});
vec[h[i][1]].push_back({h[i][0],l[i]});
}
deque<int>dq={0};
vector<bool>vis(n);
vis[0]=1;
int c=0;
while(dq.size()){
c++;
int a=dq.front();
dq.pop_front();
for(auto &i:vec[a]){
if(!vis[i.first]){
vis[i.first]=1;
vct[a].push_back(i);
dq.push_back(i.first);
}
}
}
assert(c==n);
dfs(0);
return (ans==LONG_LONG_MAX?-1:ans);
}