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Submission #828712

# Submission time Handle Problem Language Result Execution time Memory
828712 2023-08-17T14:06:20 Z NK_ Hotspot (NOI17_hotspot) C++17
100 / 100
 610 ms 123540 KB 
// Success consists of going from failure to failure without loss of enthusiasm
#include <bits/stdc++.h>
 
using namespace std;
 
#define nl '\n'
#define pb push_back 
#define mp make_pair
#define f first
#define s second
#define sz(x) int(x.size())
 
template<class T> using V = vector<T>;
using vi = V<int>;
using ll = long long;
using pi = pair<int, int>;
using vpi = V<pi>;
using vl = V<ll>;
using db = long double;


const db eps = 1e-10;
const int INF = 1e9 + 10;

int main() {
	cin.tie(0)->sync_with_stdio(0);
 	
	int N, M; cin >> N >> M;
	V<vi> adj(N); for(int i = 0; i < M; i++) {
		int u, v; cin >> u >> v;
		adj[u].pb(v);
		adj[v].pb(u);
	}

	V<vi> ways(N, vi(N)), dst(N, vi(N, INF));

	auto bfs = [&](int r) {
		if (ways[r][r] != 0) return;
		// cout << "BFS: " << r << endl;
		vi vis(N, 0);
		queue<int> q; q.push(r);
		ways[r][r] = 1, dst[r][r] = 0;

		while(sz(q)) {
			int u = q.front(); q.pop();
			// cout << u << endl;

			if (vis[u]) continue;
			vis[u] = 1;

			for(auto& v : adj[u]) {
				if (dst[r][v] > (dst[r][u] + 1)) {
					dst[r][v] = dst[r][u] + 1; ways[r][v] = 0;
					q.push(v); 
					// cout << "NEI: " << v << endl;
				}
				if (dst[r][v] == (dst[r][u] + 1)) {
					ways[r][v] += ways[r][u];
				}
			}
		}
	};

	int K; cin >> K;
	vpi Q(K);
	for(int i = 0; i < K; i++) {
		int a, b; cin >> a >> b;
		Q[i] = mp(a, b);
		bfs(a); bfs(b);
	}

	for(int a = 0; a < N; a++) for(int b = 0; b < N; b++) if (dst[a][b] == INF) {
		dst[a][b] = dst[b][a];
		ways[a][b] = ways[b][a];
	}


	db best = -1; int ans = -1;

	auto through = [&](int a, int w, int b) {
		if ((dst[a][w] + dst[w][b]) != dst[a][b]) return db(0);

		int all = ways[a][b];
		int allw = ways[a][w] * ways[w][b];

		// cout << a << " " << w << " " << b << endl;
		// cout << all << " - " << allw << endl;

		return db(allw) / db(all);
	};

	for(int u = 0; u < N; u++) {
		db E = 0;
		for(int i = 0; i < K; i++) E += through(Q[i].f, u, Q[i].s);		

		// cout << u << " " << E << endl;

		if (best + eps < E) ans = u, best = E;
	}

	cout << ans << nl;

	exit(0-0);
}

Subtask #1
4.0 / 4.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2388 KB Output is correct
2 Correct 4 ms 5448 KB Output is correct
3 Correct 3 ms 4692 KB Output is correct
4 Correct 0 ms 340 KB Output is correct
5 Correct 1 ms 1108 KB Output is correct
6 Correct 1 ms 724 KB Output is correct
7 Correct 2 ms 2460 KB Output is correct

Subtask #2
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2388 KB Output is correct
2 Correct 4 ms 5448 KB Output is correct
3 Correct 3 ms 4692 KB Output is correct
4 Correct 0 ms 340 KB Output is correct
5 Correct 1 ms 1108 KB Output is correct
6 Correct 1 ms 724 KB Output is correct
7 Correct 2 ms 2460 KB Output is correct
8 Correct 1 ms 724 KB Output is correct
9 Correct 2 ms 2644 KB Output is correct
10 Correct 4 ms 5708 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Correct 0 ms 324 KB Output is correct
13 Correct 1 ms 1108 KB Output is correct
14 Correct 2 ms 3284 KB Output is correct

Subtask #3
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2388 KB Output is correct
2 Correct 4 ms 5448 KB Output is correct
3 Correct 3 ms 4692 KB Output is correct
4 Correct 0 ms 340 KB Output is correct
5 Correct 1 ms 1108 KB Output is correct
6 Correct 1 ms 724 KB Output is correct
7 Correct 2 ms 2460 KB Output is correct
8 Correct 1 ms 1236 KB Output is correct
9 Correct 3 ms 3396 KB Output is correct
10 Correct 3 ms 2772 KB Output is correct
11 Correct 5 ms 5844 KB Output is correct
12 Correct 1 ms 340 KB Output is correct
13 Correct 1 ms 372 KB Output is correct
14 Correct 2 ms 1236 KB Output is correct

Subtask #4
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2388 KB Output is correct
2 Correct 4 ms 5448 KB Output is correct
3 Correct 3 ms 4692 KB Output is correct
4 Correct 0 ms 340 KB Output is correct
5 Correct 1 ms 1108 KB Output is correct
6 Correct 1 ms 724 KB Output is correct
7 Correct 2 ms 2460 KB Output is correct
8 Correct 1 ms 724 KB Output is correct
9 Correct 2 ms 2644 KB Output is correct
10 Correct 4 ms 5708 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Correct 0 ms 324 KB Output is correct
13 Correct 1 ms 1108 KB Output is correct
14 Correct 2 ms 3284 KB Output is correct
15 Correct 1 ms 1236 KB Output is correct
16 Correct 3 ms 3396 KB Output is correct
17 Correct 3 ms 2772 KB Output is correct
18 Correct 5 ms 5844 KB Output is correct
19 Correct 1 ms 340 KB Output is correct
20 Correct 1 ms 372 KB Output is correct
21 Correct 2 ms 1236 KB Output is correct
22 Correct 2 ms 1620 KB Output is correct
23 Correct 1 ms 1316 KB Output is correct
24 Correct 3 ms 3540 KB Output is correct
25 Correct 6 ms 6996 KB Output is correct
26 Correct 5 ms 6100 KB Output is correct
27 Correct 1 ms 468 KB Output is correct
28 Correct 3 ms 1732 KB Output is correct

Subtask #5
26.0 / 26.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2388 KB Output is correct
2 Correct 4 ms 5448 KB Output is correct
3 Correct 3 ms 4692 KB Output is correct
4 Correct 0 ms 340 KB Output is correct
5 Correct 1 ms 1108 KB Output is correct
6 Correct 1 ms 724 KB Output is correct
7 Correct 2 ms 2460 KB Output is correct
8 Correct 1 ms 724 KB Output is correct
9 Correct 2 ms 2644 KB Output is correct
10 Correct 4 ms 5708 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Correct 0 ms 324 KB Output is correct
13 Correct 1 ms 1108 KB Output is correct
14 Correct 2 ms 3284 KB Output is correct
15 Correct 1 ms 532 KB Output is correct
16 Correct 2 ms 1876 KB Output is correct
17 Correct 6 ms 4516 KB Output is correct
18 Correct 4 ms 3668 KB Output is correct
19 Correct 8 ms 7380 KB Output is correct
20 Correct 2 ms 724 KB Output is correct
21 Correct 1 ms 460 KB Output is correct

Subtask #6
36.0 / 36.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2388 KB Output is correct
2 Correct 4 ms 5448 KB Output is correct
3 Correct 3 ms 4692 KB Output is correct
4 Correct 0 ms 340 KB Output is correct
5 Correct 1 ms 1108 KB Output is correct
6 Correct 1 ms 724 KB Output is correct
7 Correct 2 ms 2460 KB Output is correct
8 Correct 1 ms 724 KB Output is correct
9 Correct 2 ms 2644 KB Output is correct
10 Correct 4 ms 5708 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Correct 0 ms 324 KB Output is correct
13 Correct 1 ms 1108 KB Output is correct
14 Correct 2 ms 3284 KB Output is correct
15 Correct 1 ms 1236 KB Output is correct
16 Correct 3 ms 3396 KB Output is correct
17 Correct 3 ms 2772 KB Output is correct
18 Correct 5 ms 5844 KB Output is correct
19 Correct 1 ms 340 KB Output is correct
20 Correct 1 ms 372 KB Output is correct
21 Correct 2 ms 1236 KB Output is correct
22 Correct 2 ms 1620 KB Output is correct
23 Correct 1 ms 1316 KB Output is correct
24 Correct 3 ms 3540 KB Output is correct
25 Correct 6 ms 6996 KB Output is correct
26 Correct 5 ms 6100 KB Output is correct
27 Correct 1 ms 468 KB Output is correct
28 Correct 3 ms 1732 KB Output is correct
29 Correct 1 ms 532 KB Output is correct
30 Correct 2 ms 1876 KB Output is correct
31 Correct 6 ms 4516 KB Output is correct
32 Correct 4 ms 3668 KB Output is correct
33 Correct 8 ms 7380 KB Output is correct
34 Correct 2 ms 724 KB Output is correct
35 Correct 1 ms 460 KB Output is correct
36 Correct 19 ms 984 KB Output is correct
37 Correct 82 ms 11272 KB Output is correct
38 Correct 610 ms 94220 KB Output is correct
39 Correct 92 ms 5204 KB Output is correct
40 Correct 218 ms 72092 KB Output is correct
41 Correct 555 ms 123540 KB Output is correct
42 Correct 202 ms 13140 KB Output is correct
43 Correct 96 ms 32040 KB Output is correct
44 Correct 88 ms 32020 KB Output is correct