Submission #546774

#	Time	Username	Problem	Language	Result	Execution time	Memory
546774		erto	Commuter Pass (JOI18_commuter_pass)	C++17	15 / 100	2095 ms	262144 KiB

commuter_pass

#include <bits/stdc++.h>
typedef long long int ll;
#define INF ll(1e18 + 7)
#define N (ll)1e5 + 5
using namespace std;
#define int ll

int n, m, s, t, u2, v, g, h, z, g2, h2;
vector<pair<int, int>> v2[N];
bool used[N];
int ds[N], du[N], dv[N];
pair<int, int> d1[N], d2[N];

void bfs(){
    memset(used, 0, sizeof(used));
    priority_queue<pair<int, int>> q;
    q.push({0, s});
    pair<int, int> p;
    while(!q.empty()){
        p = q.top();
        q.pop();
        if(used[p.second])continue;
        used[p.second] = 1;
        for(auto u : v2[p.second]){
            if(!used[u.first] && ds[u.first] > ds[p.second] + u.second){
                ds[u.first] = ds[p.second] + u.second;
                q.push({-ds[u.first], u.first});
            }
        }
    }
}

void bfs2(){
    memset(used, 0, sizeof(used));
    priority_queue<pair<int, int>> q;
    q.push({0, u2});
    pair<int, int> p;
    while(!q.empty()){
        p = q.top();
        q.pop();
        if(used[p.second])continue;
        used[p.second] = 1;
        for(auto u : v2[p.second]){
            if(!used[u.first] && du[u.first] > du[p.second] + u.second){
                du[u.first] = du[p.second] + u.second;
                q.push({-du[u.first], u.first});
            }
        }
    }
}

void bfs3(){
    memset(used, 0, sizeof(used));
    priority_queue<pair<int, int>> q;
    q.push({0, v});
    pair<int, int> p;
    while(!q.empty()){
        p = q.top();
        q.pop();
        if(used[p.second])continue;
        used[p.second] = 1;
        for(auto u : v2[p.second]){
            if(!used[u.first] && dv[u.first] > dv[p.second] + u.second){
                dv[u.first] = dv[p.second] + u.second;
                q.push({-dv[u.first], u.first});
            }
        }
    }
}

void solve(){
    cin >> n >> m >> s >> t >> u2 >> v;
    for(int i=0; i<m; i++){
        cin >> g >> h >> z;
        v2[g].push_back({h, z});
        v2[h].push_back({g, z});
    }
    fill(ds, ds+n+1, INF);
    fill(du, du+n+1, INF);
    fill(dv, dv+n+1, INF);
    fill(d1, d1 + n + 1, make_pair(INF, INF));
    fill(d2, d2 + n + 1, make_pair(INF, INF));
    ds[s] = du[u2] = dv[v] = 0;
    bfs();
    bfs2();
    bfs3();

    for(int i=1; i<=n; i++){
        d1[i] = d2[i] = {du[i], dv[i]};
    }
    int t1, t2, t3, t4;

    memset(used, 0, sizeof(used));
    priority_queue<pair<int, int>> q;
    q.push({0, s});
    pair<int, int> p;
    while(!q.empty()){
        p = q.top();
        q.pop();
        g = d1[p.second].first, g2= d1[p.second].second, h = d2[p.second].first, h2= d2[p.second].second;
        for(auto u : v2[p.second]){
            if(ds[u.first] == ds[p.second] + u.second){
                t1 = min(g, du[u.first]);
                t2 = min(g2, dv[u.first]);
                t3 = min(h, du[u.first]);
                t4 = min(h2, dv[u.first]);
                
                d1[u.first] = {t1, t2};
                
                d2[u.first] = {t3, t4};
                q.push({-ds[u.first], u.first});
            }
        }       
    }
    cout<< min(min(d1[t].first + d1[t].second, d2[t].first + d2[t].second), du[v]);

}
 
signed main(){
    //freopen("shortcut.in", "r", stdin);
    //freopen("shortcut.out", "w", stdout);
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int T = 1;
    //cin>>T;
    while (T--){
        solve();
    }
}

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