Submission #645779

#	Time	Username	Problem	Language	Result	Execution time	Memory
645779		swagchicken	Commuter Pass (JOI18_commuter_pass)	C++14	100 / 100	652 ms	27840 KiB

commuter_pass

/*
 ID: swagchicken1
 PROG:
 LANG: C++11
 */
 
#include <iostream>
#include <tuple>
#include <cmath>
#include <string>
#include <cstring>
#include <vector>
#include <deque>
#include <queue>
#include <stack>
#include <map>
#include <unordered_map>
#include <set>
#include <unordered_set>
#include <algorithm>
#include <vector>
#include <fstream>
#include <iomanip>
#include <ctime>
#include <cctype>
#include <climits>
#include <chrono>
#include <numeric>
#include <functional>
 
using namespace std;
 
typedef long long ll;
typedef vector<int> vi;
typedef vector< vector <int> > vvi;
typedef pair<int, int> pii;
typedef pair < pair < int, int >, int > piii;
typedef pair < pair <int, int > , pair <int, int> > piiii;
typedef pair<ll, ll> pll;
typedef vector<bool> vb;
typedef vector<char> vc;
typedef vector<string> vs;
 
#define FOR(i,a,b) for(int i = a; i < b; i ++)
#define RFOR(i,a,b) for(int i = a-1; i >= b; i --)
#define all(a) a.begin(), a.end()
#define endl '\n';
#define sz(x) (int)(x).size()
 
#define mp make_pair
#define pb push_back
#define ff first
#define ss second
 
template <typename T>
void pr(vector<T> &v) {
    FOR(i, 0, sz(v)) cout << v[i] << " ";
    cout << endl;
}
template <typename T>
void pr(vector<vector<T> > &v) {
    FOR(i, 0, sz(v)) { pr(v[i]); }
}
template <typename T>
void re(T &x) {
    cin >> x;
}
template <typename T>
void re(vector<T> &a) {
    FOR(i, 0, sz(a)) re(a[i]);
}
template <class Arg, class... Args>
void re(Arg &first, Args &... rest) {
    re(first);
    re(rest...);
}
template <typename T>
void pr(T x) {
    cout << x << endl;
}
template <class Arg, class... Args>
void pr(const Arg &first, const Args &... rest) {
    cout << first << " ";
    pr(rest...);
    cout << endl;
}
void ps() { cout << endl; }
template<class T, class... Ts>
void ps(const T& t, const Ts&... ts) {
    cout << t; if (sizeof...(ts)) cout << " "; ps(ts...);
}
 
const ll MOD  = 1000000007;
#define inf 1e18;
#define INF INT_MAX
//#define DEBUG
 
long double PI = 4*atan(1);
long double eps = 1e-9;

int n,m, S,T,U,V;
vector<vector<pair<int, ll>>> adj;
vector<ll> distS, distT, distU, distV;
ll ans;

void dijkstra(int start, vector<ll>& dist) {
    FOR(i,0,n) dist[i] = 1e18;
    dist[start] = 0;
    set<pair<ll, int>> pq;
    pq.insert({0, start});
    while(!pq.empty()) {
        pair<ll, int> curr = *pq.begin();
        pq.erase(pq.find(curr));
        
        int u = curr.ss;
        ll d = curr.ff;
        for(pair<int, ll> nxt : adj[u]) {
            int v = nxt.ff; ll w = nxt.ss;
            if(d + w < dist[v]) {
                if(pq.find({dist[v], v}) != pq.end()) pq.erase(pq.find({dist[v], v}));
                dist[v] = d+w;
                pq.insert({d + w, v});
            }
        }
    }
}



void search(int start) {
    set<pair<ll,  int>> pq;
    vector<ll> minUA(n);
    vector<ll> minVA(n);
    vector<ll> dist(n);
    FOR(i,0,n) {
        minUA[i] = 1e18;
        minVA[i] = 1e18;
        dist[i] = 1e18;
    }
    minUA[start] = distU[start];
    minVA[start] = distV[start];

    dist[start] = 0;
    pq.insert({dist[start], start});

    while(!pq.empty()) {
        pair<ll, int> curr = *pq.begin();
        pq.erase(pq.find(curr));
        
        int u = curr.ss;
        ll d = curr.ff;

        
        ans = min(ans, minUA[u] + distV[u]);
        ans = min(ans, minVA[u] + distU[u]);
    //    cout << u << " " << minUA[u] << " " << distV[u] << " " << ans <<  endl;

        for(pair<int, ll> nxt : adj[u]) {
            int v = nxt.ff; ll w = nxt.ss;

            if(d + w + distT[v] == distS[T]) {
                minUA[v] = min(minUA[v], min(minUA[u], distU[v]));
                minVA[v] = min(minVA[v], min(minVA[u], distV[v]));
            }

            if(d + w < dist[v]) {
                if(pq.find({dist[v], v}) != pq.end()) pq.erase(pq.find({dist[v], v}));
                dist[v] = d+w;
                pq.insert({d + w, v});
            }
        }
    }


}

int main() {
    //auto start = chrono::high_resolution_clock::now();
    ios_base::sync_with_stdio(0);cin.tie(0);
    //ofstream cout("output.txt");
    //ifstream cin("input.txt");
    #ifdef DEBUG
        freopen("input.txt", "r", stdin);
        freopen("output.txt", "w", stdout);
        // freopen("cowmbat.in", "r", stdin);
        // freopen("cowmbat.out", "w", stdout);
    #endif

    cin >> n >> m;
    cin >> S >> T; S--; T--;
    cin >> U >> V; U--; V--;
    adj.resize(n);
    distS.resize(n);
    distT.resize(n);
    distU.resize(n);
    distV.resize(n);
    FOR(i,0,m) {
        int u,v,w; cin >> u >> v >> w;
        u--; v--;
        adj[u].pb({v,w});
        adj[v].pb({u,w});
    }

    dijkstra(S, distS);
    dijkstra(T, distT);
    dijkstra(U, distU);
    dijkstra(V, distV);

    ans = distU[V];
    search(S);
    cout << ans << endl;




    


    
    



    
    //auto stop = chrono::high_resolution_clock::now();
    //auto duration = chrono::duration_cast<chrono::microseconds>(stop - start);
    //cout << duration.count() << endl;
    //cin.close();
    //cout.close();
}
    

    

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