Submission #366969

#	Time	Username	Problem	Language	Result	Execution time	Memory
366969		Return_0	Commuter Pass (JOI18_commuter_pass)	C++17	15 / 100	2093 ms	155516 KiB

commuter_pass

#pragma GCC optimize("Ofast,unroll-loops")
// #pragma comment(linker, "/stack:200000000")
// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,fma,tune=native")

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

typedef long long ll;
typedef long double ld;
typedef pair <ll, ll> pll;

#ifdef SINA
#define dbg(...) __f(#__VA_ARGS__, __VA_ARGS__)
template <typename Arg1> void __f(const char* name, Arg1&& arg1) { cout << name << " : " << arg1 << std::endl; }
template <typename Arg1, typename... Args> void __f (const char* names, Arg1&& arg1, Args&&... args) {
	const char* comma = strchr(names + 1, ',');cout.write(names, comma - names) << " : " << arg1<<" | ";__f(comma+1, args...); }
#define dbg2(x, j, n) cout<< #x << " : "; output((j), (n), x, 1); cout.flush();
#else
#define dbg(...) 0
#define dbg2(x, j, n) 0
#endif
#define SZ(x) ((ll)((x).size()))
#define File(s, t) freopen(s ".txt", "r", stdin); freopen(t ".txt", "w", stdout);
#define input(j, n, a) for (int _i = (j); _i < (n)+(j); _i++) cin>> a[_i];
#define output(j, n, a, t) for (int _i = (j); _i < (n)+(j); _i++) cout<< a[_i] << (((t) && _i != (n)+(j)-1)? ' ' : '\n');
#define kill(x) return cout<< x << endl, 0
#define cl const ll
#define fr first
#define sc second
#define lc (v << 1)
#define rc (lc | 1)
#define mid ((l + r) >> 1)
#define All(x) (x).begin(), (x).end()

cl inf = sizeof(ll) == 4 ? (1e9 + 10) : (3e18), mod = 1e9 + 7, MOD = 998244353;

template <class A, class B> ostream& operator << (ostream& out, const pair<A, B> &a) {
	return out << '(' << a.first << ", " << a.second << ')';    }
template <class A> ostream& operator << (ostream& out, const vector<A> &a) {
	out << '['; for (int i = -1; ++i < (int)(a.size());) out<< a[i] << (i < (int)(a.size()) - 1 ? ", " : ""); return out << ']'; }
template <class T, typename _t = less <T> > using Tree = tree <T, null_type, _t, rb_tree_tag, tree_order_statistics_node_update>;

cl N = 4e5 + 7;

ll n, m, S, T, V, U, cur, dis [N];
vector <pll> adj [N], vec;
vector <ll> adj2 [N];
priority_queue <pll> pq;

void dijkstra (ll st = S) {
	memset(dis, 63, sizeof dis);
	dis[st] = 0;
	pq.push({0, st});
	while (!pq.empty()) {
		auto [d, v] = pq.top();
		pq.pop(); d = -d;
		if (dis[v] != d)	continue;
		for (auto [u, w] : adj[v]) if (dis[u] > d + w)	dis[u] = d + w, pq.push({-dis[u], u});
	}
}

bool dfs (ll v = S) {
	if (v == cur)	return true;
	bool ok = false;
	for (auto &u : adj2[v])	if (dfs(u))	vec.push_back({v, u}), ok = 1;
	return ok;
}

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

	cin>> n >> m >> S >> T >> V >> U;
	for (ll i = 0, v, u, w; i < m; i++) {
		cin>> v >> u >> w;
		adj[v].push_back({u, w});
		adj[u].push_back({v, w});
	}

	dijkstra();
	for (ll v = 1; v <= n; v++) for (auto [u, w] : adj[v]) if (dis[v] + w == dis[u])	adj2[v].push_back(u);
	cur = T; dfs();
	for (auto [v, u] : vec)	adj[v + n].push_back({u + n, 0});

	for (ll i = 1; i <= n; i++)	adj2[i].clear();
	vec.clear();
	dijkstra(T);
	for (ll v = 1; v <= n; v++) for (auto [u, w] : adj[v]) if (dis[v] + w == dis[u])	adj2[v].push_back(u);
	cur = S; dfs(T);
	for (auto [v, u] : vec)	adj[v + n + n].push_back({u + n + n, 0});

	for (ll v = 1; v <= n; v++)	{
		adj[v + n].push_back({v + n + n + n, 0});
		adj[v + n + n].push_back({v + n + n + n, 0});
		for (auto &x : adj[v])	adj[v + n + n + n].push_back(x);
	}
	for (ll v = 1; v <= n; v++)	adj[v].push_back({v + n, 0}), adj[v].push_back({v + n + n, 0});

	dijkstra(V);
	cout<< dis[U + n + n + n] << endl;

	cerr<< "\nTime elapsed: " << 1000 * clock() / 1000 << "ms\n";

	return 0;
}
/*

*/

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