Submission #334471

#	Time	Username	Problem	Language	Result	Execution time	Memory
334471		ncduy0303	Hotspot (NOI17_hotspot)	C++17	100 / 100	827 ms	250988 KiB

hotspot

#include <bits/stdc++.h>

using namespace std;

#define ar array
#define ll long long

const int MAX_N = 5e3 + 1;
const int MOD = 1e9 + 7;
const int INF = 1e9;
const ll LINF = 1e18;

int n, m, k;
vector<int> adj[MAX_N];
ll dist[MAX_N][MAX_N], cnt[MAX_N][MAX_N];
double p[MAX_N];

void bfs(int s) {
	queue<ar<int,2>> q;
	q.push({0, s});
	dist[s][s] = 0; cnt[s][s] = 1;
	while (!q.empty()){
		auto [d, u] = q.front(); q.pop();
		if (d > dist[s][u]) continue;
		for (int v : adj[u]) {
			if (dist[s][v] > dist[s][u] + 1) { 
				dist[s][v] = dist[s][u] + 1;
                cnt[s][v] = cnt[s][u];
				q.push({dist[s][v], v});
			}
			else if (dist[s][v] == dist[s][u] + 1) {
                cnt[s][v] += cnt[s][u];
            }
		}
	}
}

void solve() {
    cin >> n >> m;
    for (int i = 0; i < m; i++) {
        int u, v; cin >> u >> v;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }
    memset(dist, 0x3f, sizeof dist);
    cin >> k;
    while (k--) {
        int u, v; cin >> u >> v;
        if (dist[u][u] > 0) bfs(u);
        if (dist[v][v] > 0) bfs(v);
        for (int i = 0; i < n; i++) {
            if (dist[u][v] == dist[u][i] + dist[v][i]) {
                p[i] += (double)(cnt[u][i] * cnt[v][i]) / cnt[u][v];
            }
        }
    }
    int ans = 0;
    for (int i = 0; i < n; i++) {
        if (p[i] > p[ans]) {
            ans = i;
        }
    }
    cout << ans << "\n";
}

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    // freopen("input.txt", "r", stdin);
    // freopen("output.txt", "w", stdout);

    int tc = 1;
    // cin >> tc;
    for (int t = 1; t <= tc; t++) {
        // cout << "Case #" << t  << ": ";
        solve();
    }
}

Compilation message (stderr)

hotspot.cpp: In function 'void bfs(int)':
hotspot.cpp:29:22: warning: narrowing conversion of 'dist[s][v]' from 'long long int' to 'int' [-Wnarrowing]
   29 |     q.push({dist[s][v], v});
      |             ~~~~~~~~~^

• Subtask 1: 4 / 4
• Subtask 2: 5 / 5
• Subtask 3: 11 / 11
• Subtask 4: 18 / 18
• Subtask 5: 26 / 26
• Subtask 6: 36 / 36