Submission #946196

#	Time	Username	Problem	Language	Result	Execution time	Memory
946196		vjudge1	Commuter Pass (JOI18_commuter_pass)	C++17	0 / 100	2051 ms	13068 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});
    }
    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