Submission #1069720

#	Time	Username	Problem	Language	Result	Execution time	Memory
1069720		Hugo1729	Commuter Pass (JOI18_commuter_pass)	C++17	16 / 100	490 ms	28248 KiB

commuter_pass

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

int n,m,a,b,c,d;

vector<pair<ll,int>> adj[100001];

vector<ll> dijkstra(int v){
    vector<ll> dist(n+1,-1);

    priority_queue<pair<ll,int>,vector<pair<ll,int>>, greater<pair<ll,int>>> pq;
    pq.push({0,v});


    while(!pq.empty()){
        auto [cost,w] = pq.top();
        pq.pop();

        if(dist[w]!=-1)continue;

        dist[w]=cost;

        for(auto [dist,e] : adj[w]){
            pq.push({dist+cost,e});
        }
    }

    return dist;
}

int main(){
    // cin.tie(0)->sync_with_stdio(0);



    cin >> n >> m >> a >> b >> c >> d;

    for(int i=0;i<m;i++){
        int x,y,cost; cin >> x >> y >> cost;
        adj[x].push_back({cost,y});
        adj[y].push_back({cost,x});
    }

    vector<ll> path1 = dijkstra(a),path2 = dijkstra(b),sus1=dijkstra(c),sus2=dijkstra(d);

    vector<ll> dp(n+1,LLONG_MAX/4),dp1(n+1,LLONG_MAX/4),dp2(n+1,LLONG_MAX/4);
    // vector<pair<ll,ll>> dp1(n+1,{LLONG_MAX,LLONG_MAX}),dp2(n+1,{LLONG_MAX,LLONG_MAX});

    vector<pair<ll,int>> jan;

    for(int i=1;i<=n;i++){
        if(path1[i]+path2[i]==path1[b])jan.push_back({path1[i],i});
    }

    dp[a]=sus1[a]+sus2[a];
    dp1[a]=sus1[a];
    dp2[a]=sus2[a];

    sort(jan.begin(),jan.end());

    for(int i=0;i<jan.size();i++){
        int v = jan[i].second;
        for(auto [cost, w] : adj[v]){
            if(path1[v]+path2[v]==path1[b]&&path1[w]<path1[v]){
                dp1[v]=min(dp1[w],sus1[v]);
                dp2[v]=min(dp2[w],sus2[v]);
                dp[v]=min(dp[v],dp[w]);
                dp[v]=min(min(sus1[v]+sus2[v],dp[v]),min(dp1[v]+sus2[v],sus1[v]+dp2[v]));
            }
        }
        // cout << v << ": " << dp[v] << ' ' << dp1[v] << ' ' << dp2[v] << '\n';
    }

    cout << min(dp[b],sus1[d]);

    // cout << '\n';

    // for(int i = 0;i<jan.size();i++)cout << jan[i].first << ' ' << jan[i].second << '\n';


    // cout << '\n';

    return 0;
}

Compilation message (stderr)

commuter_pass.cpp: In function 'int main()':
commuter_pass.cpp:62:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   62 |     for(int i=0;i<jan.size();i++){
      |                 ~^~~~~~~~~~~

• Subtask 1: 16 / 16
• Subtask 2: 0 / 15
• Subtask 3: 0 / 24
• Subtask 4: 0 / 45