Submission #600251

#	Time	Username	Problem	Language	Result	Execution time	Memory
600251		vbee	Commuter Pass (JOI18_commuter_pass)	C++14	31 / 100	275 ms	21352 KiB

commuter_pass

#include <bits/stdc++.h>
#define fi first
#define se second
#define all(r) (r).begin(), (r).end()
#define MASK(i) (1 << (i))
#define BIT(x, i) ((x) >> (i) & 1)
#define ll long long
#define pb push_back
#define TASK "task"

using namespace std;

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

const int oo = 1e9 + 7;
const ll loo = (ll)1e18 + 7;
const int LOG = 18;
const int BASE = 323;
const int N = 1e5 + 7;

int n, m, s, t, u, v;
ll dist[N], dist2[N], revdist[N];
vector<pair<ll, ll> > g[N];
int main(){
    ios_base::sync_with_stdio(0); cin.tie(0);
    // freopen(TASK".inp", "r", stdin);
    // freopen(TASK".out", "w", stdout);
    cin >> n >> m >> s >> t >> u >> v;
    for (int i = 1; i <= m; i++){
        int a, b, c; cin >> a >> b >> c;
        g[a].pb({b, c});
        g[b].pb({a, c});
    }
    for (int i = 1; i <= n; i++) {
        dist[i] = loo;
        dist2[i] = loo;
        revdist[i] = loo;
    }
    dist[s] = 0;
    priority_queue<pair<ll, ll>, vector<pair<ll, ll> >, greater<pair<ll, ll>> > kew;
    kew.push({0, s});
    while (!kew.empty()){
        auto k = kew.top();
        kew.pop();
        if (dist[k.se] < k.fi) continue;
        for (auto u : g[k.se]){
            if (u.se + k.fi < dist[u.fi]){
                dist[u.fi] = u.se + k.fi;
                kew.push({dist[u.fi], u.fi});
            }
        }
    }
    revdist[t] = 0;
    kew.push({0, t});
    while (!kew.empty()){
        auto k = kew.top();
        kew.pop();
        if (revdist[k.se] < k.fi) continue;
        for (auto u : g[k.se]){
            if (u.se + k.fi  < revdist[u.fi]){
                revdist[u.fi] = u.se + k.fi;
                kew.push({revdist[u.fi], u.fi});
            }
        }
    }
    dist2[u] = 0;
    kew.push({0, u});
    while (!kew.empty()){
        auto k = kew.top();
        kew.pop();
        if (dist2[k.se] < k.fi) continue;
        for (auto u : g[k.se]){
            int cost = u.se;
            if (dist[k.se] + u.se + revdist[u.fi] == dist[t] || revdist[k.se] + u.se + dist[u.fi] == revdist[s])
                cost = 0;
            if (cost + k.fi < dist2[u.fi]){
                dist2[u.fi] = cost + k.fi;
                kew.push({dist2[u.fi], u.fi});
            }                
        }
    }
    cout << dist2[v];
    // for (int i = 1; i <= n; i++){
    //     cout << dist[i] << " " << revdist[i] << "\n";
    // }
    return 0;
}

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