Submission #1157816

#	Time	Username	Problem	Language	Result	Execution time	Memory
1157816		Alfraganus	Commuter Pass (JOI18_commuter_pass)	C++20	100 / 100	282 ms	22160 KiB

commuter_pass

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

#define int long long
#define str string
#define endl '\n'
#define fs first
#define ss second
#define all(a) a.begin(), a.end()

#define print(a) for(auto x : a) cout << x << ' '; cout << endl;
#define printmp(a) for(auto x : a) cout << x[0] << ' ' << x[1] << endl;

const int mod = 1e9 + 7;

void solve(){
    int n, m, s, t, u, v;
    cin >> n >> m >> s >> t >> u >> v;
    vector<vector<array<int, 2>>> graph(n + 1);
    for(int i = 0; i < m; i ++){
        int a, b, c;
        cin >> a >> b >> c;
        graph[a].push_back({b, c});
        graph[b].push_back({a, c});
    }
    vector<int> d1(n + 1, 1e18), d2(n + 1, 1e18);
    set<array<int, 2>> st;
    st.insert({0, u});
    d1[u] = 0;
    while(!st.empty()){
        array<int, 2> x = *st.begin();
        st.erase(st.begin());

        for(auto y : graph[x[1]]){
            if(d1[y[0]] > x[0] + y[1]){
                st.erase({d1[y[0]], y[0]});
                d1[y[0]] = x[0] + y[1];
                st.insert({d1[y[0]], y[0]});
            }
        }
    }
    d2[v] = 0;
    st.insert({0, v});
    while(!st.empty()){
        array<int, 2> x = *st.begin();
        st.erase(st.begin());

        for(auto y : graph[x[1]]){
            if(d2[y[0]] > x[0] + y[1]){
                st.erase({d2[y[0]], y[0]});
                d2[y[0]] = x[0] + y[1];
                st.insert({d2[y[0]], y[0]});
            }
        }
    }
    vector<int> mn(n + 1, 1e18), s1(n + 1), s2(n + 1);
    set<array<int, 3>> stt;
    stt.insert({0ll, d1[s] + d2[s], s});
    mn[s] = 0;
    s1[s] = d1[s];
    s2[s] = d2[s];
    while(!stt.empty()){
        array<int, 3> x = *stt.begin();
        stt.erase(stt.begin());

        for(auto y : graph[x[2]]){
            if(mn[y[0]] > x[0] + y[1]){
                stt.erase({mn[y[0]], s1[y[0]] + s2[y[0]], y[0]});
                s1[y[0]] = min(d1[y[0]], s1[x[2]]);
                s2[y[0]] = min(d2[y[0]], s2[x[2]]);
                mn[y[0]] = x[0] + y[1];
                stt.insert({mn[y[0]], s1[y[0]] + s2[y[0]], y[0]});
            }
            else if(mn[y[0]] == x[0] + y[1]){
                if(s1[y[0]] + s2[y[0]] > min(d2[y[0]], s2[x[2]]) + min(d1[y[0]], s1[x[2]])){
                    stt.erase({mn[y[0]], s1[y[0]] + s2[y[0]], y[0]});
                    s1[y[0]] = min(d1[y[0]], s1[x[2]]);
                    s2[y[0]] = min(d2[y[0]], s2[x[2]]);
                    stt.insert({mn[y[0]], s1[y[0]] + s2[y[0]], y[0]});
                }
            }
        }
    }
    cout << min(d1[v], s1[t] + s2[t]);
}

signed main(){
    ios::sync_with_stdio(0);
    cin.tie(0), cout.tie(0);
    int t = 1;
    // cin >> t;
    while(t --){
        solve();
        cout << endl;
    }
}

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