Submission #1094852

#	Time	Username	Problem	Language	Result	Execution time	Memory
1094852		TrinhKhanhDung	Commuter Pass (JOI18_commuter_pass)	C++14	100 / 100	166 ms	18828 KiB

commuter_pass

#include <bits/stdc++.h>
#define ll long long
#define fi first
#define se second
#define sz(x) (int)x.size()
#define ALL(v) v.begin(),v.end()
#define MASK(k) (1LL << (k))
#define BIT(x, i) (((x) >> (i)) & 1)
#define oo (ll)1e18
#define INF (ll)1e9
#define MOD (ll)(1e9 + 7)

using namespace std;

template<class T1, class T2>
    bool maximize(T1 &a, T2 b){if(a < b){a = b; return true;} return false;}

template<class T1, class T2>
    bool minimize(T1 &a, T2 b){if(a > b){a = b; return true;} return false;}

template<class T1, class T2>
    void add(T1 &a, T2 b){a += b; if(a >= MOD) a -= MOD;}

template<class T1, class T2>
    void sub(T1 &a, T2 b){a -= b; if(a < 0) a += MOD;}

template<class T>
    void cps(T &v){sort(ALL(v)); v.resize(unique(ALL(v)) - v.begin());}

const int MAX_N = 1e5 + 10;

int N, M, S, T, U, V;
ll distS[MAX_N], distU[MAX_N], distV[MAX_N], minCostU[MAX_N], minCostV[MAX_N];
vector<pair<int, int>> adj[MAX_N];
bool visited[MAX_N];

void dijkstra(ll dist[], int s){
    memset(dist, 0x3f, (N + 3) * sizeof(ll));
    dist[s] = 0;

    priority_queue<pair<ll, int>, vector<pair<ll, int>>, greater<pair<ll, int>>> pq;
    pq.push(make_pair(0, s));

    while(!pq.empty()){
        int u = pq.top().se;
        ll kc = pq.top().fi;
        pq.pop();

        if(kc > dist[u]) continue;

        for(pair<int, int> o: adj[u]){
            int v = o.fi;
            ll newkc = kc + o.se;
            if(minimize(dist[v], newkc)){
                pq.push(make_pair(newkc, v));
            }
        }
    }
}

void solve(){
    cin >> N >> M >> S >> T >> U >> V;
    for(int i = 1; i <= M; i++){
        int u, v, c;
        cin >> u >> v >> c;

        adj[u].push_back(make_pair(v, c));
        adj[v].push_back(make_pair(u, c));
    }

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

    memset(minCostU, 0x3f, sizeof minCostU);
    memset(minCostV, 0x3f, sizeof minCostV);

    priority_queue<pair<ll, int>> pq;
    pq.push(make_pair(distS[T], T));
    minCostU[T] = distU[T];
    minCostV[T] = distV[T];
    visited[T] = true;

    ll ans = distU[V];

    while(!pq.empty()){
        int u = pq.top().se;
        pq.pop();

        minCostU[u] = distU[u];
        minCostV[u] = distV[u];

        for(pair<int, int> o: adj[u]){
            int v = o.fi, kc = o.se;

            if(!visited[v] && distS[u] == distS[v] + kc){
                visited[v] = true;
                pq.push(make_pair(distS[v], v));
            }

            if(distS[u] + kc == distS[v]){
                minimize(minCostU[u], minCostU[v]);
                minimize(minCostV[u], minCostV[v]);
            }
        }

        minimize(ans, distU[u] + minCostV[u]);
        minimize(ans, distV[u] + minCostU[u]);
    }

    cout << ans << '\n';

}

int main(){
    ios_base::sync_with_stdio(0); cin.tie(0);
//     freopen("capsomayman.inp","r",stdin);
//     freopen("capsomayman.out","w",stdout);

    int t = 1;
//    cin >> t;
    while(t--){
        solve();
    }

    return 0;
}

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