Submission #684276

#	Time	Username	Problem	Language	Result	Execution time	Memory
684276		infertechno2	Evacuation plan (IZhO18_plan)	C++14	54 / 100	874 ms	43204 KiB

plan

#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long ll;
 
const ll Size=1e5+1;
 
vector<pair<ll,ll>> adj[Size];
ll safety[Size],dist[Size];
bool visited[Size];
queue<ll> to_process;
ll n,m;
 
void calc_danger(){
    set<pair<ll,ll>> to_process;
    for(ll i=1;i<=n;i++){
        to_process.insert({safety[i],i});
    }
    while(to_process.size()){
        pair<ll,ll> curr_node=*to_process.begin();
        to_process.erase(curr_node);
        while(to_process.size() and visited[curr_node.second]){
            curr_node=*to_process.begin();
            to_process.erase(curr_node);
        }
        visited[curr_node.second]=1;
        for(auto itr:adj[curr_node.second]){
            if(safety[itr.first]>safety[curr_node.second]+itr.second){
                to_process.erase({safety[itr.first],itr.first});
                safety[itr.first]=safety[curr_node.second]+itr.second;
                to_process.insert({safety[itr.first],itr.first});
            }
        }
    }
}
 
ll dijkstra(ll start_node,ll end_node){
    set<pair<ll,ll>> to_process;
    for(ll i=1;i<=n;i++){
        if(i!=start_node){
            dist[i]=0;
        }else{
            dist[i]=safety[i];
        }
        to_process.insert({dist[i],i});
        visited[i]=0;
    }
    while(to_process.size()){
        pair<ll,ll> curr_node=*to_process.rbegin();
        to_process.erase(curr_node);
        while(to_process.size() and visited[curr_node.second]){
            curr_node=*to_process.rbegin();
            to_process.erase(curr_node);
        }
        visited[curr_node.second]=1;
        for(auto itr:adj[curr_node.second]){
            if(dist[itr.first]<min(dist[curr_node.second],itr.second)){
                to_process.erase({dist[itr.first],itr.first});
                dist[itr.first]=min(dist[curr_node.second],itr.second);
                to_process.insert({dist[itr.first],itr.first});
            }
        }
    }
    return dist[end_node];
}
 
void solve(){
    cin>>n>>m;
    for(ll i=0;i<=n;i++){
        safety[i]=1e18;
    }
    for(ll i=0;i<m;i++){
        ll from,to,w;
        cin>>from>>to>>w;
        adj[from].push_back({to,w});
        adj[to].push_back({from,w});
    }
    ll k;
    cin>>k;
    for(ll i=0;i<k;i++){
        ll v;
        cin>>v;
        safety[v]=0;
    }
    calc_danger();
    for(ll i=1;i<=n;i++){
        for(ll j=0;j<adj[i].size();j++){
            adj[i][j]={adj[i][j].first,safety[adj[i][j].first]};
        }
    }
    ll q;
    cin>>q;
    if(q>1 and n>1e3){
        while(q--){
            ll from,to;
            cin>>from>>to;
            ll ans=min(safety[from],safety[to]);
            cout<<ans<<"\n";
        }
    }else{
        while(q--){
            ll from,to;
            cin>>from>>to;
            ll ans=dijkstra(from,to);
            cout<<ans<<"\n";
        }
    }
}
 
int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    ll t=1;
    while(t--){
        solve();
    }
    return 0;
}
/*
9 12
1 9 4
1 2 5
2 3 7
2 4 3
4 3 6
3 6 4
8 7 10
6 7 5
5 8 1
9 5 7
5 4 12
6 8 2
2
4 7
5
1 6
5 3
4 8
5 8
1 5
 
*/

Compilation message (stderr)

plan.cpp: In function 'void solve()':
plan.cpp:88:21: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   88 |         for(ll j=0;j<adj[i].size();j++){
      |                    ~^~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 13 / 13
• Subtask 3: 12 / 12
• Subtask 4: 19 / 19
• Subtask 5: 0 / 46