Submission #330159

#	Time	Username	Problem	Language	Result	Execution time	Memory
330159		Kevin_Zhang_TW	Commuter Pass (JOI18_commuter_pass)	C++17	100 / 100	470 ms	27308 KiB

commuter_pass

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define pb emplace_back
#define AI(i) begin(i), end(i)
template<class T>
bool chmax(T &a, T b) { return a < b ? (a = b, true) : false; }
template<class T> 
bool chmin(T &a, T b) { return b < a ? (a = b, true) : false; }
#ifdef KEV
#define DE(args...) kout("[ " + string(#args) + " ] = ", args)
void kout() { cerr << endl; }
template<class T, class ...U>
void kout(T a, U ...b) { cerr << a << ' ', kout(b...); }
template<class T>
void debug(T L, T R) { while (L != R) cerr << *L << " \n"[next(L) == R], ++L; }
#else
#define DE(...) 0
#define debug(...) 0
#endif

const int MAX_N = 100010;
const ll inf = 1ll << 55;
int n, m, S, T, S2, T2;
ll ds[MAX_N], dt[MAX_N], d1[MAX_N], d2[MAX_N];
vector<pair<int,int>> edge[MAX_N];
vector<int> dage[MAX_N], reve[MAX_N];
void dij(int s, ll* dis) {
	static bool vis[MAX_N];
	fill(vis, vis+n+1, false);
	fill(dis, dis+n+1, inf);
	priority_queue<pair<ll,ll>, vector<pair<ll,ll>>, greater<pair<ll,ll>> > pq;

	dis[s] = 0;
	pq.emplace(0, s);
	while (pq.size()) {
		auto [len, x] = pq.top(); pq.pop();
		if (vis[x]) continue;
		vis[x] = true;
		for (auto [u, w] : edge[x])
			if (!vis[u] && chmin(dis[u], dis[x] + w))
				pq.emplace(dis[u], u);
	} 
}

int od[MAX_N], ol;
void getod() {
	vector<int> deg(n+1);
	for (int i = 1;i <= n;++i)
		for (int u : dage[i])
			++deg[u];
	for (int i = 1;i <= n;++i) if (deg[i] == 0)
		od[ol++] = i;
	for (int i = 0;i < ol;++i) {
		int x = od[i];
		for (int u : dage[x]) 
			if (--deg[u] == 0) od[ol++] = u;
	}
}
ll dagdp() {
	getod();
	ll res = min(d1[S] + d2[S], d1[T2]);

	for (int i = 0;i < ol;++i) { 
		int x = od[i];
		if (dage[x].size() + reve[x].size() == 0) continue;
		DE(x);
		chmin(res, d1[x] + d2[x]);

		for (int u : reve[x])
			chmin(res, min(d1[u] + d2[x], d1[x] + d2[u]));
		for (int u : reve[x])
			chmin(d1[x], d1[u]), chmin(d2[x], d2[u]);
	}

	return res; 
}
ll solve() {
	dij(S, ds), dij(T, dt), dij(S2, d1), dij(T2, d2);

	ll len = ds[T];
	DE(len);

	for (int i = 1;i <= n;++i)
		for (auto [u, w] : edge[i]) if (ds[i] + w + dt[u] == len)
			dage[i].pb(u), reve[u].pb(i);

	return dagdp(); 
}
int32_t main() {
	ios_base::sync_with_stdio(0), cin.tie(0);
	cin >> n >> m >> S >> T >> S2 >> T2;
	for (int a, b, c, i = 0;i < m;++i) {
		cin >> a >> b >> c;
		edge[a].pb(b, c);
		edge[b].pb(a, c);
	}
	cout << solve() << '\n'; 
} 

Compilation message (stderr)

commuter_pass.cpp: In function 'll dagdp()':
commuter_pass.cpp:18:17: warning: statement has no effect [-Wunused-value]
   18 | #define DE(...) 0
      |                 ^
commuter_pass.cpp:67:3: note: in expansion of macro 'DE'
   67 |   DE(x);
      |   ^~
commuter_pass.cpp: In function 'll solve()':
commuter_pass.cpp:18:17: warning: statement has no effect [-Wunused-value]
   18 | #define DE(...) 0
      |                 ^
commuter_pass.cpp:82:2: note: in expansion of macro 'DE'
   82 |  DE(len);
      |  ^~

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