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Submission #276542

# Submission time Handle Problem Language Result Execution time Memory
276542 2020-08-20T13:39:36 Z islingr Olympic Bus (JOI20_ho_t4) C++17
100 / 100
 429 ms 3456 KB 
#include <bits/stdc++.h>
#include <ext/pb_ds/priority_queue.hpp>
using namespace std;

#define rep(i, a, b) for (auto i = (a); i < (b); ++i)
#define all(x...) begin(x), end(x)

using ll = long long;

template<class T> bool ckmin(T &a, const T &b) { return a > b ? a = b, 1 : 0; }
template<class T> bool ckmax(T &a, const T &b) { return a < b ? a = b, 1 : 0; }

const int N = 1 << 9, M = 1 << 16;
const ll inf = 1e18;

int n;
ll d[N][N];
int a[M], b[M], w[M], c[M];
vector<int> g[N];
bool onPath[M], vis[N];

bool dfs(int u, int t) {
	if (u == t) return true;
	vis[u] = true;
	for (int e : g[u]) {
		assert(a[e] == u);
		int v = b[e];
		assert(d[u][t] <= w[e] + d[v][t]);
		if (!vis[v] && w[e] + d[v][t] == d[u][t] && dfs(v, t))
			return onPath[e] = true;
	}
	return false;
}


using pq_t = __gnu_pbds::priority_queue<pair<ll, int>, greater<>>;
pq_t::point_iterator it[N];

ll dij(int s, int t) {
	pq_t pq;
	rep(u, 0, n) if (u != s) it[u] = pq.push({inf, u});
	it[s] = pq.push({0, s});

	while (!pq.empty()) {
		 ll dist; int u;
		tie(dist, u) = pq.top();
		pq.pop(); it[u] = nullptr;
		if (u == t) return dist;
		for (int e : g[u]) {
			int v = b[e];
			if (it[v] != nullptr) {
				dist += w[e];
				if (dist < it[v]->first)
					pq.modify(it[v], {dist, v});
				dist -= w[e];
			}
		}
	}
	return inf;
}

signed main() {
	cin.tie(nullptr)->sync_with_stdio(false);

	int m; cin >> n >> m;
	rep(u, 0, n) rep(v, 0, n) d[u][v] = inf;
	rep(u, 0, n) d[u][u] = 0;
	rep(e, 0, m) {
		cin >> a[e] >> b[e] >> w[e] >> c[e], --a[e], --b[e];
		ckmin(d[a[e]][b[e]], ll(w[e]));
		g[a[e]].push_back(e);
	}

	rep(w, 0, n)
		rep(u, 0, n)
			rep(v, 0, n)
				ckmin(d[u][v], d[u][w] + d[w][v]);

	int s = 0, t = n - 1;
	fill(vis, vis + n, 0); dfs(s, t);
	fill(vis, vis + n, 0); dfs(t, s);

	ll ans = d[s][t] + d[t][s];
	rep(e, 0, m) {
		if (!onPath[e]) {
			ll to = min(d[s][t], d[s][b[e]] + w[e] + d[a[e]][t]);
			ll fr = min(d[t][s], d[t][b[e]] + w[e] + d[a[e]][s]);
			ckmin(ans, c[e] + to + fr);
		} else {
			g[a[e]].erase(find(all(g[a[e]]), e));
			swap(a[e], b[e]);
			g[a[e]].push_back(e);
			ckmin(ans, c[e] + dij(0, n - 1) + dij(n - 1, 0));
			g[a[e]].pop_back();
			swap(a[e], b[e]);
			g[a[e]].push_back(e);
		}
	}

	cout << (ans < inf ? ans : -1);
}

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 14 ms 1280 KB Output is correct
2 Correct 10 ms 1152 KB Output is correct
3 Correct 13 ms 1280 KB Output is correct
4 Correct 13 ms 1280 KB Output is correct
5 Correct 2 ms 512 KB Output is correct
6 Correct 10 ms 1152 KB Output is correct
7 Correct 1 ms 384 KB Output is correct
8 Correct 1 ms 384 KB Output is correct
9 Correct 1 ms 384 KB Output is correct
10 Correct 26 ms 1280 KB Output is correct
11 Correct 30 ms 1280 KB Output is correct
12 Correct 31 ms 1280 KB Output is correct
13 Correct 11 ms 1280 KB Output is correct
14 Correct 12 ms 1280 KB Output is correct
15 Correct 12 ms 1280 KB Output is correct
16 Correct 12 ms 1280 KB Output is correct

Subtask #2
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 36 ms 2936 KB Output is correct
2 Correct 36 ms 2808 KB Output is correct
3 Correct 37 ms 3064 KB Output is correct
4 Correct 13 ms 1276 KB Output is correct
5 Correct 12 ms 1272 KB Output is correct
6 Correct 19 ms 1152 KB Output is correct
7 Correct 10 ms 1152 KB Output is correct
8 Correct 1 ms 384 KB Output is correct
9 Correct 38 ms 2944 KB Output is correct
10 Correct 33 ms 2944 KB Output is correct
11 Correct 40 ms 2936 KB Output is correct
12 Correct 36 ms 2936 KB Output is correct
13 Correct 36 ms 2944 KB Output is correct
14 Correct 37 ms 2944 KB Output is correct

Subtask #3
21.0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 1280 KB Output is correct
2 Correct 12 ms 1256 KB Output is correct
3 Correct 59 ms 2432 KB Output is correct
4 Correct 10 ms 1152 KB Output is correct
5 Correct 105 ms 2936 KB Output is correct
6 Correct 1 ms 384 KB Output is correct
7 Correct 0 ms 384 KB Output is correct
8 Correct 29 ms 3192 KB Output is correct
9 Correct 33 ms 3200 KB Output is correct
10 Correct 83 ms 3200 KB Output is correct
11 Correct 65 ms 3200 KB Output is correct
12 Correct 71 ms 3320 KB Output is correct
13 Correct 1 ms 420 KB Output is correct
14 Correct 1 ms 384 KB Output is correct
15 Correct 1 ms 384 KB Output is correct
16 Correct 1 ms 384 KB Output is correct
17 Correct 1 ms 384 KB Output is correct
18 Correct 1 ms 384 KB Output is correct
19 Correct 107 ms 3192 KB Output is correct
20 Correct 93 ms 3300 KB Output is correct
21 Correct 84 ms 3200 KB Output is correct
22 Correct 75 ms 3328 KB Output is correct

Subtask #4
63.0 / 63.0

# Verdict Execution time Memory Grader output
1 Correct 14 ms 1280 KB Output is correct
2 Correct 10 ms 1152 KB Output is correct
3 Correct 13 ms 1280 KB Output is correct
4 Correct 13 ms 1280 KB Output is correct
5 Correct 2 ms 512 KB Output is correct
6 Correct 10 ms 1152 KB Output is correct
7 Correct 1 ms 384 KB Output is correct
8 Correct 1 ms 384 KB Output is correct
9 Correct 1 ms 384 KB Output is correct
10 Correct 26 ms 1280 KB Output is correct
11 Correct 30 ms 1280 KB Output is correct
12 Correct 31 ms 1280 KB Output is correct
13 Correct 11 ms 1280 KB Output is correct
14 Correct 12 ms 1280 KB Output is correct
15 Correct 12 ms 1280 KB Output is correct
16 Correct 12 ms 1280 KB Output is correct
17 Correct 36 ms 2936 KB Output is correct
18 Correct 36 ms 2808 KB Output is correct
19 Correct 37 ms 3064 KB Output is correct
20 Correct 13 ms 1276 KB Output is correct
21 Correct 12 ms 1272 KB Output is correct
22 Correct 19 ms 1152 KB Output is correct
23 Correct 10 ms 1152 KB Output is correct
24 Correct 1 ms 384 KB Output is correct
25 Correct 38 ms 2944 KB Output is correct
26 Correct 33 ms 2944 KB Output is correct
27 Correct 40 ms 2936 KB Output is correct
28 Correct 36 ms 2936 KB Output is correct
29 Correct 36 ms 2944 KB Output is correct
30 Correct 37 ms 2944 KB Output is correct
31 Correct 17 ms 1280 KB Output is correct
32 Correct 12 ms 1256 KB Output is correct
33 Correct 59 ms 2432 KB Output is correct
34 Correct 10 ms 1152 KB Output is correct
35 Correct 105 ms 2936 KB Output is correct
36 Correct 1 ms 384 KB Output is correct
37 Correct 0 ms 384 KB Output is correct
38 Correct 29 ms 3192 KB Output is correct
39 Correct 33 ms 3200 KB Output is correct
40 Correct 83 ms 3200 KB Output is correct
41 Correct 65 ms 3200 KB Output is correct
42 Correct 71 ms 3320 KB Output is correct
43 Correct 1 ms 420 KB Output is correct
44 Correct 1 ms 384 KB Output is correct
45 Correct 1 ms 384 KB Output is correct
46 Correct 1 ms 384 KB Output is correct
47 Correct 1 ms 384 KB Output is correct
48 Correct 1 ms 384 KB Output is correct
49 Correct 107 ms 3192 KB Output is correct
50 Correct 93 ms 3300 KB Output is correct
51 Correct 84 ms 3200 KB Output is correct
52 Correct 75 ms 3328 KB Output is correct
53 Correct 41 ms 3320 KB Output is correct
54 Correct 39 ms 3320 KB Output is correct
55 Correct 41 ms 3328 KB Output is correct
56 Correct 13 ms 1280 KB Output is correct
57 Correct 13 ms 1280 KB Output is correct
58 Correct 148 ms 2936 KB Output is correct
59 Correct 182 ms 3064 KB Output is correct
60 Correct 238 ms 3064 KB Output is correct
61 Correct 146 ms 2940 KB Output is correct
62 Correct 172 ms 2936 KB Output is correct
63 Correct 241 ms 2972 KB Output is correct
64 Correct 397 ms 3016 KB Output is correct
65 Correct 385 ms 2936 KB Output is correct
66 Correct 429 ms 3064 KB Output is correct
67 Correct 15 ms 2176 KB Output is correct
68 Correct 34 ms 3456 KB Output is correct
69 Correct 33 ms 3456 KB Output is correct
70 Correct 49 ms 3456 KB Output is correct
71 Correct 40 ms 3448 KB Output is correct
72 Correct 36 ms 3456 KB Output is correct
73 Correct 43 ms 3456 KB Output is correct
74 Correct 37 ms 3456 KB Output is correct