oj.uz

Submission #276496

# Submission time Handle Problem Language Result Execution time Memory
276496 2020-08-20T13:14:56 Z islingr Olympic Bus (JOI20_ho_t4) C++17
0 / 100
 1000 ms 5524 KB 
#include <bits/stdc++.h>
using namespace std;

#define rep(i, a, b) for (auto i = (a); i < (b); ++i)

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];
		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 = u != a[e] ? a[e] : b[e];
				pq.push({-(dist[u] + w[e]), v});
			}
		} else assert(!ckmin(dist[u], -pq.top().first));
		pq.pop();
	}
	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(i, 0, n) d[i][i] = 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]);

	fill(vis, vis + n, 0); dfs(0, n - 1);
	fill(vis, vis + n, 0); dfs(n - 1, 0);

	ll ans = d[0][n - 1] + d[n - 1][0];
	rep(e, 0, m) {
		if (!onPath[e]) {
			ll to = min(d[0][n - 1], d[0][b[e]] + w[e] + d[a[e]][n - 1]);
			ll fr = min(d[n - 1][0], d[n - 1][b[e]] + w[e] + d[a[e]][0]);
			ckmin(ans, c[e] + to + fr);
		} else {
			swap(a[e], b[e]);
			ckmin(ans, c[e] + dij(0, n - 1) + dij(n - 1, 0));
			swap(a[e], b[e]);
		}
	}
	cout << (ans < inf ? ans : -1);
}

Subtask #1
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 24 ms 1280 KB Output is correct
2 Correct 12 ms 1152 KB Output is correct
3 Correct 14 ms 1280 KB Output is correct
4 Correct 15 ms 1280 KB Output is correct
5 Correct 3 ms 640 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 424 KB Output is correct
10 Correct 53 ms 1280 KB Output is correct
11 Correct 69 ms 1280 KB Output is correct
12 Incorrect 71 ms 1312 KB Output isn't correct
13 Halted 0 ms 0 KB -

Subtask #2
0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 203 ms 5168 KB Output is correct
2 Correct 196 ms 5320 KB Output is correct
3 Correct 194 ms 5524 KB Output is correct
4 Correct 18 ms 1280 KB Output is correct
5 Correct 13 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 Incorrect 1 ms 512 KB Output isn't correct
9 Halted 0 ms 0 KB -

Subtask #3
0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 32 ms 1280 KB Output is correct
2 Correct 10 ms 1152 KB Output is correct
3 Execution timed out 1084 ms 3428 KB Time limit exceeded
4 Halted 0 ms 0 KB -

Subtask #4
0 / 63.0

# Verdict Execution time Memory Grader output
1 Correct 24 ms 1280 KB Output is correct
2 Correct 12 ms 1152 KB Output is correct
3 Correct 14 ms 1280 KB Output is correct
4 Correct 15 ms 1280 KB Output is correct
5 Correct 3 ms 640 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 424 KB Output is correct
10 Correct 53 ms 1280 KB Output is correct
11 Correct 69 ms 1280 KB Output is correct
12 Incorrect 71 ms 1312 KB Output isn't correct
13 Halted 0 ms 0 KB -