Submission #946197

#	Time	Username	Problem	Language	Result	Execution time	Memory
946197		Medetbek	Commuter Pass (JOI18_commuter_pass)	C++17	0 / 100	43 ms	8028 KiB

commuter_pass

//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
//#pragma GCC optimize("Ofast,unroll-loops,fast-math,O3")

#include <map>
#include <set>
#include <list>
#include <cmath>
#include <ctime>
#include <deque>
#include <queue>
#include <stack>
#include <string>
#include <bitset>
#include <cstdio>
#include <limits>
#include <vector>
#include <climits>
#include <cstring>
#include <cstdlib>
#include <fstream>
#include <numeric>
#include <sstream>
#include <cassert>
#include <iomanip>
#include <iostream>
#include <algorithm>
#include <stdio.h>
#include <fstream>
#include <unordered_map>
#define ll long long
#define int long long
#define all(v) v.begin(), v.end()
#define nl '\n'
#define pb push_back
#define sz(s) (int)(s).size()
#define f first
#define s second
using namespace std;
const ll N = 1e5 + 50, MX = 1e18;
bool was[N];
void solve(){
    ll n,m;
    cin >> n >> m;
    vector <pair <int, int> > g[n + 1];
    ll s, t, u, v;
    cin >> s >> t >> u >> v;
    for(int i = 1; i <= n; i++){
        ll a, b, x;
        cin >> a >> b >> x;
        g[a].pb({b,x});
        g[b].pb({a, x});
    }
    if(n <= 300) {
        ll ds[n + 1], dt[n + 1], du[n + 1], dv[n + 1];
        if (true) {
            for (int i = 1; i <= n; i++) {
                was[i] = 0;
                ds[i] = dt[i] = MX;
            }
            ds[s] = 0;
            priority_queue<pair<int, int> > q;
            q.push({0, s});
            while (!q.empty()) {
                ll v = q.top().s;
                q.pop();
                if (was[v])continue;
                was[v] = 1;
                for (auto [to, w]: g[v]) {
                    if (ds[v] + w < ds[to]) {
                        ds[to] = ds[v] + w;
                        q.push({-ds[to], to});
                    }
                }
            }
        }
        if (true) {
            for (int i = 1; i <= n; i++) {
                was[i] = 0;
                du[i] = MX;
            }
            du[u] = 0;
            priority_queue<pair<int, int>> q;
            q.push({0, u});
            while (!q.empty()) {
                ll v = q.top().s;
                q.pop();
                if (was[v])continue;
                was[v] = 1;
                for (auto [to, w]: g[v]) {
                    if (du[v] + w < du[to]) {
                        du[to] = du[v] + w;
                        q.push({-du[to], to});
                    }
                }
            }
            //cout << du[v] << nl;
        }
        if (true) {
            for (int i = 1; i <= n; i++) {
                was[i] = 0;
                dv[i] = MX;
            }
            dv[v] = 0;
            priority_queue<pair<int, int>> q;
            q.push({0, v});
            while (!q.empty()) {
                ll v = q.top().s;
                q.pop();
                if (was[v])continue;
                was[v] = 1;
                for (auto [to, w]: g[v]) {
                    if (dv[v] + w < dv[to]) {
                        dv[to] = dv[v] + w;
                        q.push({-dv[to], to});
                    }
                }
            }
        }
        if (true) {
            for (int i = 1; i <= n; i++) {
                was[i] = 0;
                dt[i] = MX;
            }
            ds[s] = 0;
            dt[t] = 0;
            priority_queue<pair<int, int>> q;
            q.push({0, t});
            while (!q.empty()) {
                ll v = q.top().s;
                q.pop();
                if (was[v])continue;
                was[v] = 1;
                for (auto [to, w]: g[v]) {
                    if (dt[v] + w < dt[to]) {
                        dt[to] = dt[v] + w;
                        q.push({-dt[to], to});
                    }
                }
            }
        }
        ll ans = du[v];
        //cout << ds[t] << nl;
        //cout << ds[3] << " " << dt[5] << nl;
        for (int i = 1; i <= n; i++) {
            ll di[n + 1];
            for (int j = 1; j <= n; j++) {
                was[j] = 0;
                di[j] = MX;
            }
            di[i] = 0;
            priority_queue<pair<int, int>> q;
            q.push({0, i});
            while (!q.empty()) {
                ll v = q.top().s;
                q.pop();
                if (was[v])continue;
                was[v] = 1;
                for (auto [to, w]: g[v]) {
                    if (di[v] + w < di[to]) {
                        di[to] = di[v] + w;
                        q.push({-di[to], to});
                    }
                }
            }
            for (int j = 1; j <= n; j++) {
                if (ds[i] + dt[j] + di[j] == ds[t] || ds[j] + dt[i] + di[j] == ds[t]) {
                    ans = min(ans, du[i] + dv[j]);
                }
            }
        }
        cout << ans << nl;
    }
}
signed main(){
    //freopen("lca.in", "r", stdin);
    //freopen("lca.out", "w", stdout);
    ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
    ll ql=1;
    //cin >> ql;
    //tst++;
    while(ql--){
        solve();
    }
}

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