Submission #1105340

#	Time	Username	Problem	Language	Result	Execution time	Memory
1105340		underwaterkillerwhale	Hotspot (NOI17_hotspot)	C++17	100 / 100	571 ms	1104 KiB

hotspot

#include <bits/stdc++.h>
#define ll long long
#define rep(i,m,n) for(int i=(m); i<=(n); i++)
#define reb(i,m,n) for(int i=(m); i>=(n); i--)
#define pii pair<int,int>
#define pll pair<ll,ll>
#define MP make_pair
#define fs first
#define se second
#define bit(msk, i) ((msk >> i) & 1)
#define iter(id, v) for(auto id : v)
#define pb push_back
#define SZ(v) (ll)v.size()
#define ALL(v) v.begin(),v.end()

using namespace std;

mt19937_64 rd(chrono :: steady_clock :: now ().time_since_epoch().count());
ll Rand (ll l, ll r) { return uniform_int_distribution<ll> (l, r) (rd); }

const int N = 5e3 + 7;
const int Mod = 1e6 + 3;///lon
const int INF = 1e9 + 7;
const ll BASE = 137;
const int szBL = 550;

int n, m, K;
pii a[N];
vector<int> ke[N];
long double Ans[N];
int D[2][N], dp[2][N];
bool vis[N];

void solution () {
    cin >> n >> m;
    rep (i, 1, m) {
        int u, v;
        cin >> u >> v;
        ++u,++v;
        ke[u].pb(v);
        ke[v].pb(u);
    }
    auto calc = [] (int S, int typ) {
        rep (i, 1, n) {
            D[typ][i] = n + 1;
            dp[typ][i] = vis[i] = 0;
        }
        queue<int> Q;
        Q.push(S);
        D[typ][S] = 0;
        dp[typ][S] = 1;
        while (!Q.empty()) {
            int u = Q.front();
            Q.pop();
            if (vis[u]) continue;
            vis[u] = 1;
            iter (&v, ke[u]) {
                if (D[typ][v] > D[typ][u] + 1) {
                    D[typ][v] = D[typ][u] + 1;
                    dp[typ][v] = dp[typ][u];
                    Q.push(v);
                }
                else if (D[typ][v] == D[typ][u] + 1)  {
                    dp[typ][v] += dp[typ][u];
                }
            }
        }
    };
    cin >> K;
    rep (j, 1, K) {
        cin >> a[j].fs >> a[j].se;
        int S, T;
        tie(S, T) = a[j];
        ++S, ++T;

        calc(S, 0);
        calc(T, 1);

        int delta = D[0][T];
        rep (u, 1, n) {
            if (D[0][u] + D[1][u] == delta) {
                Ans[u] += 1.0 * (dp[0][u] * dp[1][u]) / dp[0][T];
            }
        }
    }
    long double res = 0;
    int opt = 0;
    rep (u, 1, n) {
        if (res < Ans[u]) {
            res = Ans[u];
            opt = u;
        }
    }
    cout << opt - 1 <<"\n";
}

#define file(name) freopen(name".inp","r",stdin); \
freopen(name".out","w",stdout);
main () {
//    file("TOY");
    ios_base :: sync_with_stdio(false); cin.tie(0); cout.tie(0);
    int num_Test = 1;
//    cin >> num_Test;
    while (num_Test--)
        solution();
    cerr << (double)clock() / CLOCKS_PER_SEC * 1000  << " ms";
}
/*
no bug challenge +12

*/

Compilation message (stderr)

hotspot.cpp:99:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   99 | main () {
      | ^~~~

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