Submission #851750

#	Time	Username	Problem	Language	Result	Execution time	Memory
851750		future	Evacuation plan (IZhO18_plan)	C++14	23 / 100	958 ms	58144 KiB

plan

#include <bits/stdc++.h>
using namespace std;
int n,q;
int m;
vector<pair<int,int>>g[100005];
long long d[100005];
long long dd[100005];
int trc[100005];
map<pair<int,int>,bool>ok;
int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    cin>>n>>m;
    while(m--) {
        int u,v,c;
        cin>>u>>v>>c;
        g[u].push_back({v,c});
        g[v].push_back({u,c});
        ok[{u,v}]=1;
    }
    int k;
    cin>>k;
    for(int i=1; i<=n; i++)d[i]=1e18;
    priority_queue<pair<long long,int>,vector<pair<long long,int>>,greater<pair<long long,int>>>pq;
    while(k--) {
        int u;
        cin>>u;
        d[u]=0;
        pq.push({0,u});
    }
    while(pq.size()) {
        auto[_,u]=pq.top();
        pq.pop();
        for(auto v:g[u])if(d[v.first]>d[u]+v.second) {
                d[v.first]=d[u]+v.second;
                pq.push({d[v.first],v.first});
            }
    }
    int q;
    cin>>q;
    while(q--) {
        int s,t;
        cin>>s>>t;
        if(ok[{s,t}]||ok[{t,s}]){cout<<min(d[s],d[t])<<'\n';continue;}
        for(int i=1; i<=n; i++)dd[i]=1e18;
    priority_queue<pair<long long,int>,vector<pair<long long,int>>,greater<pair<long long,int>>>pq;
    dd[s]=0;
    pq.push({0,s});
      while(pq.size()) {
        auto[_,u]=pq.top();
        pq.pop();
        for(auto v:g[u])if(dd[v.first]>dd[u]+v.second) {
                dd[v.first]=dd[u]+v.second;
                trc[v.first]=u;
                pq.push({dd[v.first],v.first});
            }
    }
    long long ans=1e18;
    while(t!=s)
    {
        //cout<<t<<'\n';
        ans=min(ans,d[t]);
        t=trc[t];
    }
    ans=min(ans,d[s]);
    cout<<ans<<'\n';
    }
    return 0;
}

Compilation message (stderr)

plan.cpp: In function 'int main()':
plan.cpp:33:13: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   33 |         auto[_,u]=pq.top();
      |             ^
plan.cpp:51:13: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   51 |         auto[_,u]=pq.top();
      |             ^

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