Submission #932407

#	Time	Username	Problem	Language	Result	Execution time	Memory
932407		a_l_i_r_e_z_a	Amusement Park (CEOI19_amusementpark)	C++17	42 / 100	2403 ms	35400 KiB

amusementpark

// In the name of God
// Hope is last to die

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

#define pb push_back
#define int long long
#define S second
#define F first
#define mp make_pair
#define smax(x, y) (x) = max((x), (y))
#define smin(x, y) (x) = min((x), (y))
#define all(x) (x).begin(), (x).end()
#define len(x) ((int)(x).size())

const int maxn = 11;
const int inf = 1e9 + 7, mod = 998244353;
int n, m, in[maxn], deg[maxn];
vector<int> adj[maxn], g[maxn];
int a[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
set<int> st;

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

    cin >> n >> m;
    for(int i = 0; i < m; i++){
        int u, v; cin >> u >> v;
        adj[u].pb(v);
    }
    vector<int> A;
    do{
        for(int i = 0; i < n; i++){
            in[a[i]] = i;
            deg[i + 1] = 0;
            g[i + 1].clear();
        }
        for(int i = 1; i <= n; i++){
            for(auto u: adj[i]){
                if(in[i] > in[u]){
                    g[u].pb(i);
                    deg[i]++;
                }
                else{
                    g[i].pb(u);
                    deg[u]++;
                }
            }
        }
        for(int i = 1; i <= n; i++) if(!deg[i]) st.insert(i);
        int x = 0;
        while(st.size()){
            int v = (*st.begin());
            x *= 10;
            x += v - 1;
            st.erase(st.begin());
            for(auto u: g[v]){
                deg[u]--;
                if(!deg[u]) st.insert(u);
            }
        }
        A.pb(x);
    } while (next_permutation(a, a + n));
    sort(all(A));
    A.resize(unique(all(A)) - A.begin());
    ll ans = 0;
    for(auto &per: A){
        for(int i = 0; i < n; i++){
            in[per % 10 + 1] = n - i;
            per /= 10;
        }
        for(int i = 1; i <= n; i++){
            for(auto u: adj[i]) if(in[u] < in[i]) ans++;
        }
    }
    cout << ((ans) % mod) << '\n';

    return 0;
}

• Subtask 1: 7 / 7
• Subtask 2: 12 / 12
• Subtask 3: 23 / 23
• Subtask 4: 0 / 21
• Subtask 5: 0 / 37