Submission #574893

#	Time	Username	Problem	Language	Result	Execution time	Memory
574893		ac2hu	Commuter Pass (JOI18_commuter_pass)	C++14	0 / 100	440 ms	262144 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});
            }
        }
    }
    pq.push({-fake_dist[s], s});
    vector<vector<pair<int,int>>> temp_adj(n);
    while(!pq.empty()){
        auto [dd, x] = pq.top();
        dd = -dd;
        pq.pop();
        for(auto [e, w] : fake_adj[x]){
            if(fake_dist[e] == fake_dist[x] + w){
                temp_adj[e].push_back({x, w});
                pq.push({-fake_dist[e], e});
            }
        }
    }
    fill(fake_dist.begin(), fake_dist.end(), 1e18);
    fake_dist[t] = 0;
    pq.push({-fake_dist[t], t});
    while(!pq.empty()){
        auto [dd, x] = pq.top();
        dd = -dd;
        pq.pop();
        if(fake_dist[x] != dd)continue;
        for(auto [e, w] : temp_adj[x]){
            if(fake_dist[e] > fake_dist[x] + w){
                fake_dist[e] = fake_dist[x] + w;
                pq.push({-fake_dist[e], e});
            }
        }
    }
    vector<int> lev(n, -1);
    pq.push({-fake_dist[t], t});
    lev[t] = 0;
    while(!pq.empty()){
        auto [dd, x] = pq.top();
        dd = -dd;
        pq.pop();
        for(auto [e, w] : temp_adj[x]){
            if(fake_dist[e] == fake_dist[x] + w){
                selected_edges.insert({min(e, x), max(e, x)});
                lev[e] = lev[x] + 1;
                pq.push({-fake_dist[e], e});
            }
        }
    }/*}}}*//*}}}*/
//    deb(selected_edges);{{{
//    deb(lev);
//    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(lev[a] < lev[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});
//        }
//    }
//    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];
//    cout << ans << "\n";
//    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(lev[a] > lev[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:43:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   43 |         auto [dd, x] = pq.top();
      |              ^
commuter_pass.cpp:46:18: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   46 |         for(auto [e, w] : fake_adj[x]){
      |                  ^
commuter_pass.cpp:57:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   57 |         auto [dd, x] = pq.top();
      |              ^
commuter_pass.cpp:61:18: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   61 |         for(auto [e, w] : temp_adj[x]){
      |                  ^
commuter_pass.cpp:72:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   72 |         auto [dd, x] = pq.top();
      |              ^
commuter_pass.cpp:75:18: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   75 |         for(auto [e, w] : temp_adj[x]){
      |                  ^

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