Submission #260338

#	Time	Username	Problem	Language	Result	Execution time	Memory
260338		AM1648	Commuter Pass (JOI18_commuter_pass)	C++17	100 / 100	469 ms	28644 KiB

commuter_pass

/* be name khoda */

#define long_enable
#include <iostream>
#include <algorithm>
#include <cstring>
#include <numeric>
#include <vector>
#include <fstream>
#include <set>
#include <queue>
using namespace std;

#ifdef long_enable
typedef long long int ll;
#else
typedef int ll;
#endif

typedef pair<ll, ll> pii;
typedef pair<pii, ll> ppi;
typedef pair<ll, pii> pip;
typedef vector<ll> vi;
typedef vector<pii> vpii;

#define forifrom(i, s, n) for (ll i = s; i < n; ++i)
#define forirto(i, n, e) for (ll i = (n) - 1; i >= e; --i)
#define fori(i, n) forifrom (i, 0, n)
#define forir(i, n) forirto (i, n, 0)

#define F first
#define S second
#define pb push_back
#define eb emplace_back
#define all(x) (x).begin(), (x).end()
#define smin(a, b) a = min(a, (b))
#define smax(a, b) a = max(a, (b))

#define debug(x) cout << #x << " -> " << (x) << endl
#define debug2(x, y) cout << #x << ' ' << #y << " -> " << (x) << ' ' << (y) << endl
#define debug3(x, y, z) cout << #x << ' ' << #y << ' ' << #z << " -> " << (x) << ' ' << (y) << ' ' << (z) << endl
#define debug4(x, y, z, t) cout << #x << ' ' << #y << ' ' << #z << ' ' << #t << " -> " << (x) << ' ' << (y) << ' ' << (z) << ' ' << (t) << endl
#define debuga(x, n) cout << #x << " -> "; fori (i1_da, n) { cout << (x)[i1_da] << ' '; } cout << endl
#define debugaa(x, n, m) cout << #x << " ->\n"; fori (i1_daa, n) { fori (i2_daa, m) { cout << (x)[i1_daa][i2_daa] << ' '; } cout << '\n'; } cout << endl

const ll MOD = 1000000007;
const ll INF = 2000000000;
const long long BIG = 1446803456761533460LL;

#define XL (x << 1)
#define XR (XL | 1)
#define MD ((l + r) >> 1)
#define Add(a, b) a = ((a) + (b)) % MOD
#define Mul(a, b) a = (1LL * (a) * (b)) % MOD

// -----------------------------------------------------------------------

const ll maxn = 100010;

ll n, m, S, T, U, V;
vpii g[maxn];
vi dag[maxn];
ll dp[maxn], ans;
ll ds[maxn], dt[maxn], du[maxn], dv[maxn];
priority_queue<pii, vpii, greater<pii>> pq;
bool vis[maxn];

void dijkstra(ll s, ll *d) {
    memset(d, 20, sizeof ds);
    memset(vis, 0, sizeof vis);
    d[s] = 0;
    pq.push({d[s], s});
    while (!pq.empty()) {
        ll x = pq.top().S;
        pq.pop();
        if (vis[x]) continue;
        vis[x] = true;
        for (auto [y, w] : g[x]) {
            if (d[x] + w < d[y]) {
                d[y] = d[x] + w;
                pq.push({d[y], y});
            }
        }
    }
}

void dfs(ll x) {
    vis[x] = true;
    dp[x] = dv[x];
    for (auto y : dag[x]) {
        if (!vis[y]) dfs(y);
        smin(dp[x], dp[y]);
    }
    smin(ans, du[x] + dp[x]);
}

int main() {
    ios_base::sync_with_stdio(false), cin.tie(0), cout.tie(0);

    cin >> n >> m >> S >> T >> U >> V; --S, --T, --U, --V;
    fori (i, m) {
        ll a, b, c; cin >> a >> b >> c; --a, --b;
        g[a].eb(b, c), g[b].eb(a, c);
    }
    dijkstra(S, ds);
    dijkstra(T, dt);
    dijkstra(U, du);
    dijkstra(V, dv);
    fori (x, n) {
        for (auto [y, w] : g[x]) {
            if (ds[x] + w + dt[y] == ds[T]) dag[x].eb(y);
        }
    }
    ans = du[V];
    memset(vis, 0, sizeof vis);
    dfs(S);
    swap(du, dv);
    memset(vis, 0, sizeof vis);
    dfs(S);
    cout << ans << '\n';

}

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