Submission #971227

#	Time	Username	Problem	Language	Result	Execution time	Memory
971227		vyshniak_n	Commuter Pass (JOI18_commuter_pass)	C++17	100 / 100	831 ms	73808 KiB

commuter_pass

#include <iostream>
#include <cmath>
#include <algorithm>
#include <stdio.h>
#include <cstdint>
#include <cstring>
#include <string>
#include <cstdlib>
#include <vector>
#include <bitset>
#include <map>
#include <queue>
#include <ctime>
#include <stack>
#include <set>
#include <list>
#include <random>
#include <deque>
#include <functional>
#include <iomanip>
#include <sstream>
#include <fstream>
#include <complex>
#include <numeric>
#include <cassert>
#include <array>
#include <tuple>
#include <unordered_map>
#include <unordered_set>
#include <thread>

typedef long long ll;
typedef long double ld;

using namespace std;

#define el '\n'
#define ff first
#define ss second
#define pb push_back
#define popb pop_back
#define point pair <ll, ll>
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()

const ll N = 1e5 + 10;
const ll INF = 2e18 + 10;
const ll inf = 2e9 + 10;

vector <point> gr[N], ngr[3 * N];
ll dist[4][3 * N], tin[N], timer = 0;

void solve() {
    ll n, m;
    cin >> n >> m;

    ll s, t, u, v;
    cin >> s >> t >> u >> v;

    ll a[m], b[m], c[m];
    for (ll i = 0; i < m; i++) {
        cin >> a[i] >> b[i] >> c[i];

        gr[a[i]].pb(make_pair(b[i], c[i]));
        gr[b[i]].pb(make_pair(a[i], c[i]));
    }

    set <point> st;
    for (ll i = 1; i <= 3 * n; i++)
        dist[0][i] = dist[1][i] = dist[2][i] = dist[3][i] = INF;

    st.insert({0, s});
    dist[0][s] = 0;

    while (!st.empty()) {
        ll ver = st.begin()->ss;
        st.erase(st.begin());

        tin[ver] = ++timer;

        for (point to : gr[ver]) {
            if (dist[0][to.ff] > dist[0][ver] + to.ss) {
                st.erase(make_pair(dist[0][to.ff], to.ff));
                dist[0][to.ff] = dist[0][ver] + to.ss;
                st.insert(make_pair(dist[0][to.ff], to.ff));
            }
        }
    }

    st.insert({0, t});
    dist[1][t] = 0;

    while (!st.empty()) {
        ll ver = st.begin()->ss;
        st.erase(st.begin());

        for (point to : gr[ver]) {
            if (dist[1][to.ff] > dist[1][ver] + to.ss) {
                st.erase(make_pair(dist[1][to.ff], to.ff));
                dist[1][to.ff] = dist[1][ver] + to.ss;
                st.insert(make_pair(dist[1][to.ff], to.ff));
            }
        }
    }

    ll way = dist[0][t];

    for (ll i = 0; i < m; i++) {
        if (tin[a[i]] > tin[b[i]])
            swap(a[i], b[i]);

        ngr[a[i]].pb(make_pair(b[i], c[i]));
        ngr[b[i]].pb(make_pair(a[i], c[i]));

        ngr[a[i] + 2 * n].pb(make_pair(b[i] + 2 * n, c[i]));
        ngr[b[i] + 2 * n].pb(make_pair(a[i] + 2 * n, c[i]));

        if (dist[0][a[i]] + c[i] + dist[1][b[i]] == way)
            ngr[a[i] + n].pb(make_pair(b[i] + n, 0));
    }

    for (ll i = 1; i <= n; i++) {
        ngr[i].pb(make_pair(i + n, 0));
        ngr[i + n].pb(make_pair(i + 2 * n, 0));
    }

    st.insert({0, u});
    dist[2][u] = 0;

    while (!st.empty()) {
        ll ver = st.begin()->ss;
        st.erase(st.begin());

        for (point to : ngr[ver]) {
            if (dist[2][to.ff] > dist[2][ver] + to.ss) {
                st.erase(make_pair(dist[2][to.ff], to.ff));
                dist[2][to.ff] = dist[2][ver] + to.ss;
                st.insert(make_pair(dist[2][to.ff], to.ff));
            }
        }
    }

    st.insert({0, v});
    dist[3][v] = 0;

    while (!st.empty()) {
        ll ver = st.begin()->ss;
        st.erase(st.begin());

        for (point to : ngr[ver]) {
            if (dist[3][to.ff] > dist[3][ver] + to.ss) {
                st.erase(make_pair(dist[3][to.ff], to.ff));
                dist[3][to.ff] = dist[3][ver] + to.ss;
                st.insert(make_pair(dist[3][to.ff], to.ff));
            }
        }
    }

    cout << min(dist[2][v + 2 * n], dist[3][u + 2 * n]) << el;
    return;
}
signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

    int tests = 1;
    //cin >> tests;

    while (tests--)
        solve();
    return 0;
}

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