Submission #114587

#	Time	Username	Problem	Language	Result	Execution time	Memory
114587		mosquir	Evacuation plan (IZhO18_plan)	C++14	100 / 100	1241 ms	37224 KiB

plan

/*
Hasan
*/
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
const int MX=1e5+9;
const ll inf=(1ll<<61);
int n,m,k,q,a[MX],par[MX],sz[MX];
ll ans[MX];
ll dis[MX];
bool vis[MX];
vector<pii>v[MX];
set<int>s[MX];
int get(int x){
    if(x==par[x])return x;
    return par[x]=get(par[x]);
}
void mrg(int x,int y,ll cost){
    x=get(x);y=get(y);
    if(x==y)return;
    if(sz[x]>sz[y])swap(x,y);
    sz[x]+=sz[y];
    par[y]=x;
    if(s[x].size()<s[y].size())swap(s[x],s[y]);
    for(auto pp:s[y]){
        if(s[x].find(pp)!=s[x].end()){
            ans[pp]=min(ans[pp],cost);
            s[x].erase(pp);
            continue;
        }
        s[x].insert(pp);
    }
    s[y].clear();
}
priority_queue<pair<ll,int> >pq;
void dij(){
    for(int i=1;i<=n;i++)dis[i]=inf,vis[i]=0;
    for(int i=1;i<=k;i++){
        dis[a[i]]=0;
        pq.push({0,a[i]});
    }
    while(!pq.empty()){
        int x=pq.top().second;
        ll c=-pq.top().first;pq.pop();
        if(vis[x])continue;
        vis[x]=1;
        for(auto pp:v[x]){
            if(dis[pp.first]>c+pp.second){
                dis[pp.first]=c+pp.second;
                pq.push({-dis[pp.first],pp.first});
            }
        }
    }
}
        vector<pair<ll,int> >edge;
int x,y,z;
int main(){
        cin>>n>>m;
        for(int i=1;i<=n;i++)sz[i]=1,par[i]=i,v[i].clear(),ans[i]=0,s[i].clear();
        for(int i=1;i<=m;i++){
            scanf("%d%d%d",&x,&y,&z);
            v[x].push_back({y,z});
            v[y].push_back({x,z});
        }
        cin>>k;
        for(int i=1;i<=k;i++)scanf("%d",&a[i]);
        dij();
        cin>>q;
        for(int i=1;i<=q;i++){
            scanf("%d%d",&x,&y);
            if(!dis[x]||!dis[y])continue;
            ans[i]=min(dis[x],dis[y]);
            s[x].insert(i);
            s[y].insert(i);
        }
        for(int i=1;i<=n;i++)edge.push_back({-dis[i],i});
        sort(edge.begin(),edge.end());
        for(auto pp:edge){
            for(auto pp1:v[pp.second]){
                if(dis[pp1.first]>=-pp.first){
                    mrg(pp.second,pp1.first,-pp.first);
                }
            }
        }
        edge.clear();
        for(int i=1;i<=q;i++)cout<<ans[i]<<endl;
}
/*
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 'int main()':
plan.cpp:63:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
             scanf("%d%d%d",&x,&y,&z);
             ~~~~~^~~~~~~~~~~~~~~~~~~
plan.cpp:68:35: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         for(int i=1;i<=k;i++)scanf("%d",&a[i]);
                              ~~~~~^~~~~~~~~~~~
plan.cpp:72:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
             scanf("%d%d",&x,&y);
             ~~~~~^~~~~~~~~~~~~~

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