oj.uz

Submission #276524

# Submission time Handle Problem Language Result Execution time Memory
276524 2020-08-20T13:26:42 Z islingr Olympic Bus (JOI20_ho_t4) C++17
16 / 100
 1000 ms 5184 KB 
#include <bits/stdc++.h>
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;
}

ll dist[N];
ll dij(int s, int t) {
	fill(dist, dist + n, inf);
	priority_queue<pair<ll, int>> pq;
	pq.push({0, s});
	while (!pq.empty()) {
		int u = pq.top().second;
		if (dist[u] == inf) {
			dist[u] = -pq.top().first;
			for (int e : g[u]) {
				int v = b[e];
				pq.push({-(dist[u] + w[e]), v});
			}
		} else assert(!ckmin(dist[u], -pq.top().first));
		pq.pop();
		if (u == t) break;
	}
	return dist[t];
}

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 23 ms 1280 KB Output is correct
2 Correct 10 ms 1152 KB Output is correct
3 Correct 19 ms 1272 KB Output is correct
4 Correct 13 ms 1280 KB Output is correct
5 Correct 2 ms 640 KB Output is correct
6 Correct 10 ms 1152 KB Output is correct
7 Correct 0 ms 384 KB Output is correct
8 Correct 0 ms 384 KB Output is correct
9 Correct 1 ms 512 KB Output is correct
10 Correct 41 ms 1280 KB Output is correct
11 Correct 53 ms 1280 KB Output is correct
12 Correct 62 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 51 ms 5056 KB Output is correct
2 Correct 54 ms 4900 KB Output is correct
3 Correct 45 ms 4180 KB Output is correct
4 Correct 13 ms 1280 KB Output is correct
5 Correct 12 ms 1280 KB Output is correct
6 Correct 10 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 33 ms 3456 KB Output is correct
10 Correct 33 ms 3456 KB Output is correct
11 Correct 114 ms 4480 KB Output is correct
12 Correct 76 ms 4588 KB Output is correct
13 Correct 81 ms 5140 KB Output is correct
14 Correct 94 ms 5184 KB Output is correct

Subtask #3
0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 32 ms 1400 KB Output is correct
2 Correct 10 ms 1152 KB Output is correct
3 Correct 817 ms 3220 KB Output is correct
4 Correct 10 ms 1280 KB Output is correct
5 Execution timed out 1087 ms 3896 KB Time limit exceeded
6 Halted 0 ms 0 KB -

Subtask #4
0 / 63.0

# Verdict Execution time Memory Grader output
1 Correct 23 ms 1280 KB Output is correct
2 Correct 10 ms 1152 KB Output is correct
3 Correct 19 ms 1272 KB Output is correct
4 Correct 13 ms 1280 KB Output is correct
5 Correct 2 ms 640 KB Output is correct
6 Correct 10 ms 1152 KB Output is correct
7 Correct 0 ms 384 KB Output is correct
8 Correct 0 ms 384 KB Output is correct
9 Correct 1 ms 512 KB Output is correct
10 Correct 41 ms 1280 KB Output is correct
11 Correct 53 ms 1280 KB Output is correct
12 Correct 62 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 51 ms 5056 KB Output is correct
18 Correct 54 ms 4900 KB Output is correct
19 Correct 45 ms 4180 KB Output is correct
20 Correct 13 ms 1280 KB Output is correct
21 Correct 12 ms 1280 KB Output is correct
22 Correct 10 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 33 ms 3456 KB Output is correct
26 Correct 33 ms 3456 KB Output is correct
27 Correct 114 ms 4480 KB Output is correct
28 Correct 76 ms 4588 KB Output is correct
29 Correct 81 ms 5140 KB Output is correct
30 Correct 94 ms 5184 KB Output is correct
31 Correct 32 ms 1400 KB Output is correct
32 Correct 10 ms 1152 KB Output is correct
33 Correct 817 ms 3220 KB Output is correct
34 Correct 10 ms 1280 KB Output is correct
35 Execution timed out 1087 ms 3896 KB Time limit exceeded
36 Halted 0 ms 0 KB -