Submission #255129

#	Time	Username	Problem	Language	Result	Execution time	Memory
255129		egekabas	Commuter Pass (JOI18_commuter_pass)	C++14	0 / 100	537 ms	32724 KiB

commuter_pass

#include <bits/stdc++.h>
#define ff first
#define ss second
#define pb push_back
#define mp make_pair
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<ll, ll> pll;
typedef pair<ull, ull> pull;
typedef pair<int, int> pii;
typedef pair<ld, ld> pld;
const ll inf = 1e18 + 7;
ll n, m;
ll s, t;
ll u, v;
vector<pll> g[100009];
vector<ll> tree[100009];
ll diss[100009];
ll dist[100009];
ll disu[100009];
ll disv[100009];
ll ans;
void dijk(ll beg, ll dis[], ll calctree, ll umin[], ll vmin[], ll bothmin[]){
    for(ll i = 1; i <= n; ++i){
        dis[i] = inf;
        if(calctree)
            umin[i] = vmin[i] = bothmin[i] = inf;
    }
    dis[beg] = 0;
    if(calctree){
        umin[beg] = disu[beg];
        vmin[beg] = disv[beg];
        bothmin[beg] = disu[beg]+disv[beg];
    }
    priority_queue<pll, vector<pll>, greater<pll>> pq;
    pq.push({dis[beg], beg});
    while(pq.size()){
        ll v = pq.top().ss;
        ll d = pq.top().ff;
        pq.pop();
        if(dis[v] < d) continue;
        for(auto u : g[v]){
            if(calctree && d+u.ss <= dis[u.ff]){
                umin[u.ff] = min(disu[u.ff], umin[v]);
                vmin[u.ff] = min(disv[u.ff], vmin[v]);
                bothmin[u.ff] = min({disu[u.ff]+vmin[u.ff],disv[u.ff]+umin[u.ff],bothmin[v]});
                tree[u.ff].pb(v);
            }
            if(d+u.ss < dis[u.ff]){
                dis[u.ff] = d+u.ss;
                pq.push({dis[u.ff], u.ff});
            }
        }
    }
}
ll um1[100009], vm1[100009], bm1[100009];
ll um2[100009], vm2[100009], bm2[100009];
ll clear[100009];
void dfs(ll v){
    clear[v] = 1;
    for(auto u : tree[v])
        if(!clear[u])
            dfs(u);
}
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    
    //freopen("in.txt", "r", stdin);
    //freopen("out.txt", "w", stdout);
    
    cin >> n >> m;
    cin >> s >> t;
    cin >> u >> v;
    while(m--){
        ll x, y, z;
        cin >> x >> y >> z;
        g[x].pb({y, z});
        g[y].pb({x, z});
    }
    ll empty[1];
    dijk(u, disu, 0, empty, empty, empty);
    dijk(v, disv, 0, empty, empty, empty);
    dijk(s, diss, 1, vm1, um1, bm1);
    for(ll i = 1; i <= n; ++i) tree[i].clear();
    dijk(t, dist, 1, vm2, um2, bm2);
    dfs(s);
    ans = disu[v];
    for(ll i = 1; i <= n; ++i){
        if(clear[i] == 0) continue;
        ans = min({ans, bm1[i], bm2[i], vm1[i]+um2[i], um1[i]+vm2[i]});
    }
    cout << ans;
}

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