Submission #1144415

#	Time	Username	Problem	Language	Result	Execution time	Memory
1144415		arafatenok	Commuter Pass (JOI18_commuter_pass)	C++17	15 / 100	501 ms	40236 KiB

commuter_pass

#include <bits/stdc++.h>
#pragma GCC optimize("Ofast,no-stack-protector,unroll-loops,fast-math,O3")
#pragma GCC optimize("Ofast")
#pragma GCC target("avx,avx2,fma")
#pragma GCC optimization("unroll-loops")
#pragma ("reroll")
#define skip continue;
#define gold ios_base::sync_with_stdio(false);cin.tie(NULL);
#define xa "\n"
#define int long long
#define all(a) a.begin(), a.end()
#define pb push_back
using namespace std;

const int mod = 1e9 + 7;
const int N = 2e5 + 7;
const int MAX = 1e9;
const int inf = 1e18;

int gcd(int a, int b) { if (b == 0) return a; else if(a == 0) return b; else return gcd(b, a % b); }
int lcm(int a, int b) { return a / gcd(a, b) * b; }

vector <pair < int, int > > g[N];
int n, m, dist[N];
int parent[N];
int x[N], y[N], w[N];
map < pair < int, int >, int > check;

void dijkstra(int start) {
    for(int i = 1; i <= n; i++){
        parent[i] = 0;
        dist[i] = inf;
    }
    set < pair < int ,int > > st;
    dist[start] = 0, st.insert({ 0, start });
    while(st.size() > 0) {
        int v = (*st.begin()).second;
        st.erase(st.begin());
        for (auto p : g[v]) {
            int to = p.first, w = p.second;
            if (dist[v] + w < dist[to]) {
                parent[to] = v;
                st.erase({ dist[to], to });
                dist[to] = dist[v] + w;
                st.insert({ dist[to], to });
            }
        }
    }
}

void solve() {
    cin >> n >> m;
    int s, t;
    cin >> s >> t;
    int u, v;
    cin >> u >> v;
    for(int i = 1; i <= m; i++){
        cin >> x[i] >> y[i] >> w[i];
        g[x[i]].pb({y[i], w[i]});
        g[y[i]].pb({x[i], w[i]});
    }
    dijkstra(s);
    int one = t, two = parent[t];
    for(int i = 1; i <= n; i++){
        g[i].clear();
    }
    while(two != 0){
        g[two].pb({one, 0});
        g[one].pb({two, 0});
        check[{one, two}] = 1;
        check[{two, one}] = 1;
        one = parent[one];
        two = parent[two];
    }
    for(int i = 1; i <= m; i++){
        if(check[{x[i], y[i]}] == 0){
            g[x[i]].pb({y[i], w[i]});
            g[y[i]].pb({x[i], w[i]});
        }
    }
    dijkstra(u);
    cout << dist[v];
}



signed main() {
    gold;
    //freopen("pails.in", "r", stdin);
    //freopen("pails.out", "w", stdout);
    int t = 1;
    int ti = 1;
    //cin >> t;
    while (t--) {
        //cout << "Case " << ti << ": ";
        solve();
        ti++;
    }
}

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