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Submission #828716

# Submission time Handle Problem Language Result Execution time Memory
828716 2023-08-17T14:08:20 Z NK_ Hotspot (NOI17_hotspot) C++17
100 / 100
 615 ms 123204 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;
		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();

			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); 
				}
				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];

		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);		

		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 2516 KB Output is correct
2 Correct 4 ms 5460 KB Output is correct
3 Correct 3 ms 4692 KB Output is correct
4 Correct 0 ms 212 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 2516 KB Output is correct

Subtask #2
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2516 KB Output is correct
2 Correct 4 ms 5460 KB Output is correct
3 Correct 3 ms 4692 KB Output is correct
4 Correct 0 ms 212 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 2516 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 5588 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Correct 0 ms 212 KB Output is correct
13 Correct 1 ms 1108 KB Output is correct
14 Correct 3 ms 3284 KB Output is correct

Subtask #3
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2516 KB Output is correct
2 Correct 4 ms 5460 KB Output is correct
3 Correct 3 ms 4692 KB Output is correct
4 Correct 0 ms 212 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 2516 KB Output is correct
8 Correct 1 ms 1236 KB Output is correct
9 Correct 3 ms 3372 KB Output is correct
10 Correct 2 ms 2772 KB Output is correct
11 Correct 5 ms 5904 KB Output is correct
12 Correct 1 ms 340 KB Output is correct
13 Correct 0 ms 280 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 2516 KB Output is correct
2 Correct 4 ms 5460 KB Output is correct
3 Correct 3 ms 4692 KB Output is correct
4 Correct 0 ms 212 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 2516 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 5588 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Correct 0 ms 212 KB Output is correct
13 Correct 1 ms 1108 KB Output is correct
14 Correct 3 ms 3284 KB Output is correct
15 Correct 1 ms 1236 KB Output is correct
16 Correct 3 ms 3372 KB Output is correct
17 Correct 2 ms 2772 KB Output is correct
18 Correct 5 ms 5904 KB Output is correct
19 Correct 1 ms 340 KB Output is correct
20 Correct 0 ms 280 KB Output is correct
21 Correct 2 ms 1236 KB Output is correct
22 Correct 2 ms 1696 KB Output is correct
23 Correct 1 ms 1236 KB Output is correct
24 Correct 4 ms 3540 KB Output is correct
25 Correct 10 ms 6996 KB Output is correct
26 Correct 6 ms 6100 KB Output is correct
27 Correct 1 ms 468 KB Output is correct
28 Correct 2 ms 1748 KB Output is correct

Subtask #5
26.0 / 26.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2516 KB Output is correct
2 Correct 4 ms 5460 KB Output is correct
3 Correct 3 ms 4692 KB Output is correct
4 Correct 0 ms 212 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 2516 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 5588 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Correct 0 ms 212 KB Output is correct
13 Correct 1 ms 1108 KB Output is correct
14 Correct 3 ms 3284 KB Output is correct
15 Correct 1 ms 596 KB Output is correct
16 Correct 2 ms 1748 KB Output is correct
17 Correct 6 ms 4528 KB Output is correct
18 Correct 5 ms 3732 KB Output is correct
19 Correct 9 ms 7228 KB Output is correct
20 Correct 2 ms 724 KB Output is correct
21 Correct 1 ms 468 KB Output is correct

Subtask #6
36.0 / 36.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2516 KB Output is correct
2 Correct 4 ms 5460 KB Output is correct
3 Correct 3 ms 4692 KB Output is correct
4 Correct 0 ms 212 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 2516 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 5588 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Correct 0 ms 212 KB Output is correct
13 Correct 1 ms 1108 KB Output is correct
14 Correct 3 ms 3284 KB Output is correct
15 Correct 1 ms 1236 KB Output is correct
16 Correct 3 ms 3372 KB Output is correct
17 Correct 2 ms 2772 KB Output is correct
18 Correct 5 ms 5904 KB Output is correct
19 Correct 1 ms 340 KB Output is correct
20 Correct 0 ms 280 KB Output is correct
21 Correct 2 ms 1236 KB Output is correct
22 Correct 2 ms 1696 KB Output is correct
23 Correct 1 ms 1236 KB Output is correct
24 Correct 4 ms 3540 KB Output is correct
25 Correct 10 ms 6996 KB Output is correct
26 Correct 6 ms 6100 KB Output is correct
27 Correct 1 ms 468 KB Output is correct
28 Correct 2 ms 1748 KB Output is correct
29 Correct 1 ms 596 KB Output is correct
30 Correct 2 ms 1748 KB Output is correct
31 Correct 6 ms 4528 KB Output is correct
32 Correct 5 ms 3732 KB Output is correct
33 Correct 9 ms 7228 KB Output is correct
34 Correct 2 ms 724 KB Output is correct
35 Correct 1 ms 468 KB Output is correct
36 Correct 20 ms 884 KB Output is correct
37 Correct 94 ms 11092 KB Output is correct
38 Correct 615 ms 93984 KB Output is correct
39 Correct 96 ms 4948 KB Output is correct
40 Correct 223 ms 72012 KB Output is correct
41 Correct 550 ms 123204 KB Output is correct
42 Correct 220 ms 12840 KB Output is correct
43 Correct 90 ms 31956 KB Output is correct
44 Correct 96 ms 31968 KB Output is correct