Submission #341306

#	Time	Username	Problem	Language	Result	Execution time	Memory
341306		AlexNeagu	Bosses (BOI16_bosses)	C++14	100 / 100	1219 ms	876 KiB

bosses

#include<bits/stdc++.h>
// #define int long long
#pragma GCC target ("avx2")
#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")
#define pb push_back
#define mp make_pair
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<ll,ll> pi;
const int mod = 1e9 + 9;
const int N = 106 * 106;
const int nax = 1e6+6;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int n;
ll ans = 2e18;
vector<int> possible_childs[5005];

ll root(int x) {
    
    queue<int> Q;
    Q.push(x);
    vector<int> d(n + 1, 2e9), p(n + 1);
    vector<ll> cnt(n + 1, 1LL);
    vector<int> ord;
    d[x] = 0;

    while(Q.size()) {
        int node = Q.front();
        ord.pb(node);
        Q.pop();
        for(auto it : possible_childs[node]) {
            if(d[node] + 1 < d[it]) {
                d[it] = d[node] + 1;
                Q.push(it);
                p[it] = node;
            }
        }
    }

    for(int i = 1; i <= n; i++) if(d[i] == 2e9) return 2e18;
    reverse(ord.begin(), ord.end());
    ll sol = 0;
    
    for(auto it : ord) {
        sol += cnt[it];
        if(it != x) {
            cnt[p[it]] += cnt[it];
        }
    }
    return sol;
}

int32_t main() {
 
    ios_base::sync_with_stdio(false);
    cin.tie(0);

    cin >> n;
    for(int i = 1; i <= n; i++) {
        int len;
        cin >> len;
        for(int j = 1; j <= len; j++) {
            int x;
            cin >> x;
            possible_childs[x].push_back(i);
        }
    }

    for(int i = 1; i <= n; i++) {
        ans = min(ans, root(i));
    }

    cout << ans << '\n';


    return 0;
}

Compilation message (stderr)

bosses.cpp:4: warning: ignoring #pragma GCC optimization [-Wunknown-pragmas]
    4 | #pragma GCC optimization ("O3")
      | 
bosses.cpp:5: warning: ignoring #pragma GCC optimization [-Wunknown-pragmas]
    5 | #pragma GCC optimization ("unroll-loops")
      |

• Subtask 1: 22 / 22
• Subtask 2: 45 / 45
• Subtask 3: 33 / 33