Submission #575015

#	Time	Username	Problem	Language	Result	Execution time	Memory
575015		ac2hu	Commuter Pass (JOI18_commuter_pass)	C++14	31 / 100	617 ms	43156 KiB

commuter_pass

#include <bits/stdc++.h>
#ifdef DEBUG
#include "../templates/debug.h"
#else 
#define deb(x...)
#endif
using namespace std;
#define int long long 
signed main() {
    iostream::sync_with_stdio(false);
    cin.tie(nullptr);cout.tie(nullptr);
    int n, m;cin >> n >> m;
    int s, t;cin >> s >> t; --s;--t;
    int u, v;cin >> u >> v; --u;--v;
    vector<array<int, 3>> fake_edg(m);
    vector<vector<pair<int, int>>> fake_adj(n);
    for(auto &[a, b, c] : fake_edg){
        cin >> a >> b >> c;
        --a;--b;
        fake_adj[a].push_back({b, c});
        fake_adj[b].push_back({a, c});
    }
    set<pair<int,int>> selected_edges;/*{{{*/
    priority_queue<pair<int,int>> pq;
    vector<int> fake_dist(n, 1e18);
    fake_dist[s] = 0;
    pq.push({-fake_dist[s], s});
    while(!pq.empty()){
        auto [dd, x] = pq.top();
        dd = -dd;
        pq.pop();
        if(fake_dist[x] != dd)continue;
        for(auto [e, w] : fake_adj[x]){
            if(fake_dist[e] > fake_dist[x] + w){
                fake_dist[e] = fake_dist[x] + w;
                pq.push({-fake_dist[e], e});
            }
        }
    }
    vector<vector<int>> temp_adj(n);
    vector<bool> visited(n, false);
    queue<int> q;
    q.push(s);
    visited[s] = true;
    while(!q.empty()){
        int x = q.front();
        q.pop();
        for(auto [e, w] : fake_adj[x]){
            if(fake_dist[e] == fake_dist[x] + w){
                temp_adj[e].push_back(x);
                if(!visited[e]){
                    visited[e] = true;
                    q.push(e);
                }
            }
        }
    }
    deb(temp_adj);
    fill(visited.begin(), visited.end(), false);
    q.push(t);
    visited[t] = true;
    while(!q.empty()){
        int x = q.front();
        q.pop();
        for(int e : temp_adj[x]){
            selected_edges.insert({min(e, x), max(e, x)});
            if(!visited[e]){
                visited[e]  = true;
                q.push(e);
            }
        }
    }
    deb(selected_edges);
    vector<vector<pair<int,int>>> adj(n);
    for(auto [a, b, c] : fake_edg){
        if(a > b)swap(a, b);
        if(selected_edges.find({a, b}) != selected_edges.end()){
            if(fake_dist[a] < fake_dist[b]){
                deb(a, b);
                adj[a].push_back({b, 0});
                adj[b].push_back({a, c});
            }
            else{
                deb(b, a);
                adj[b].push_back({a, 0});
                adj[a].push_back({b, c});
            }
        }
        else{
            adj[a].push_back({b, c});
            adj[b].push_back({a, c});
        }
    }
    deb(adj);
    vector<int> dist(n, 1e18);
    dist[u] = 0;
    pq.push({-dist[u], u});
    while(!pq.empty()){
        auto [dd, x] = pq.top();
        pq.pop();
        dd = -dd;
        if(dist[x] != dd)continue;
        for(auto [e, w] : adj[x]){
            if(dist[e] > dist[x] + w){
                dist[e] = dist[x] + w;
                pq.push({-dist[e], e});
            }
        }
    }
    int ans = dist[v];
    adj.clear();
    adj.resize(n);
    for(auto [a, b, c] : fake_edg){/*{{{*/
        if(a > b)swap(a, b);
        if(selected_edges.find({a, b}) != selected_edges.end()){
            if(fake_dist[a] > fake_dist[b]){
                deb(a, b);
                adj[a].push_back({b, 0});
                adj[b].push_back({a, c});
            }
            else{
                deb(b, a);
                adj[b].push_back({a, 0});
                adj[a].push_back({b, c});
            }
        }
        else{
            adj[a].push_back({b, c});
            adj[b].push_back({a, c});
        }
    }
    fill(dist.begin(), dist.end(), 1e18);
    dist[u] = 0;
    pq.push({-dist[u], u});
    while(!pq.empty()){
        auto [dd, x] = pq.top();
        pq.pop();
        dd = -dd;
        if(dist[x] != dd)continue;
        for(auto [e, w] : adj[x]){
            if(dist[e] > dist[x] + w){
                dist[e] = dist[x] + w;
                pq.push({-dist[e], e});
            }
        }
    }
    ans = min(ans, dist[v]);
    cout << ans << "\n";/*}}}*//*}}}*/
}

Compilation message (stderr)

commuter_pass.cpp: In function 'int main()':
commuter_pass.cpp:17:15: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   17 |     for(auto &[a, b, c] : fake_edg){
      |               ^
commuter_pass.cpp:29:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   29 |         auto [dd, x] = pq.top();
      |              ^
commuter_pass.cpp:33:18: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   33 |         for(auto [e, w] : fake_adj[x]){
      |                  ^
commuter_pass.cpp:48:18: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   48 |         for(auto [e, w] : fake_adj[x]){
      |                  ^
commuter_pass.cpp:75:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   75 |     for(auto [a, b, c] : fake_edg){
      |              ^
commuter_pass.cpp:99:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   99 |         auto [dd, x] = pq.top();
      |              ^
commuter_pass.cpp:103:18: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  103 |         for(auto [e, w] : adj[x]){
      |                  ^
commuter_pass.cpp:113:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  113 |     for(auto [a, b, c] : fake_edg){/*{{{*/
      |              ^
commuter_pass.cpp:136:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  136 |         auto [dd, x] = pq.top();
      |              ^
commuter_pass.cpp:140:18: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  140 |         for(auto [e, w] : adj[x]){
      |                  ^

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