Submission #683493

#	Time	Username	Problem	Language	Result	Execution time	Memory
683493		yogesh_sane	Commuter Pass (JOI18_commuter_pass)	C++17	16 / 100	250 ms	19264 KiB

commuter_pass

#include <iostream>
#include <vector>
#include <queue>
#include <stack>
#include <climits>
using namespace std;
void dfs(int s, vector<vector<int>> &adj, vector<bool> &on_sp, vector<bool> &visited){
    if(visited[s])
        return;
    visited[s] = true;
    on_sp[s] = true;
    for(auto u : adj[s])
        dfs(u,adj,on_sp,visited);
}
int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    //freopen("in.txt","r",stdin);
    int n, m, s, t, u, v;
    cin >> n >> m >> s >> t >> u >> v;
    vector<vector<pair<int, int>>> adj(n+1);
    for(int i = 0; i < m; i++){
        int a, b, c;
        cin >> a >> b >> c;
        adj[a].push_back({b,c});
        adj[b].push_back({a,c});
    }
    priority_queue<pair<long long, int>> q;
    vector<long long>dist(n+1,LONG_LONG_MAX);
    vector<bool> visited(n+1);
    vector<vector<int>>parents(n+1);
    vector<bool> on_sp(n+1);
    q.push({0,s});
    dist[s] = 0;
    while(!q.empty()){
        int node = q.top().second;
        long long dist_node = -q.top().first;
        q.pop();
        if(visited[node])
            continue;
        visited[node] = true;
        for(auto edge : adj[node]){
            int next = edge.first;
            int weight = edge.second;
            if(dist[node] + weight < dist[next]){
                dist[next] = dist[node] + weight;
                parents[next].clear();
                parents[next].push_back(node);
                q.push({-dist[next],next});
            }else if(dist[node] + weight == dist[next]){
                parents[next].push_back(node);
            }
        }
    }
    fill(visited.begin(), visited.end(), false);
    dfs(t,parents,on_sp,visited);

    fill(visited.begin(), visited.end(), false);
    vector<long long> distV(n+1, LONG_LONG_MAX);
    q.push({0,v});
    distV[v] = 0;
    while(!q.empty()){
        int node = q.top().second;
        long long dist_node = -q.top().first;
        q.pop();
        if(visited[node])
            continue;
        visited[node] = true;
        for(auto edge : adj[node]){
            int next = edge.first;
            int weight = edge.second;
            if(distV[node] + weight < distV[next]){
                distV[next] = distV[node] + weight;
                q.push({-distV[next],next});
            }
        }
    }
    long long ans = LONG_LONG_MAX;
    for(int i = 1; i <= n; i++)
        if(on_sp[i])
            ans = min(ans, distV[i]);

    cout << ans << '\n';
    return 0;
}

Compilation message (stderr)

commuter_pass.cpp: In function 'int main()':
commuter_pass.cpp:37:19: warning: unused variable 'dist_node' [-Wunused-variable]
   37 |         long long dist_node = -q.top().first;
      |                   ^~~~~~~~~
commuter_pass.cpp:64:19: warning: unused variable 'dist_node' [-Wunused-variable]
   64 |         long long dist_node = -q.top().first;
      |                   ^~~~~~~~~

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