Submission #920178

#	Time	Username	Problem	Language	Result	Execution time	Memory
920178		Alihan_8	Bitaro’s Party (JOI18_bitaro)	C++17	100 / 100	1371 ms	521828 KiB

bitaro

#include <bits/stdc++.h>

using namespace std;

#define all(x) x.begin(), x.end()
#define ar array
#define pb push_back
#define ln '\n'
#define int long long

using i64 = long long;

template <class F, class _S>
bool chmin(F &u, const _S &v){
    bool flag = false;
    if ( u > v ){
        u = v; flag |= true;
    }
    return flag;
}

template <class F, class _S>
bool chmax(F &u, const _S &v){
    bool flag = false;
    if ( u < v ){
        u = v; flag |= true;
    }
    return flag;
}

const int B = 321;

signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int n, m, q; cin >> n >> m >> q;
    vector <vector<int>> G(n);
    for ( int i = 1; i <= m; i++ ){
        int u, v; cin >> u >> v;
        --u, --v;
        G[u].pb(v);
    }
    vector <vector<int>> dp(n, vector <int> (B, -1)), fa(n, vector <int> (B, -1));
    for ( int i = 0; i < n; i++ ){
        dp[i][0] = 0;
        fa[i][0] = i;
    }
    vector <int> aux(n);
    for ( int u = 0; u < n; u++ ){
        for ( auto &v: G[u] ){
            vector <int> tmp(B, -1), tmp_(B, -1), er;
            int L = 0, R = 0, sz = 0;
            while ( L < B || R < B ){
                if ( sz == B ) break;
                {
                    while ( L < B && (fa[u][L] != -1 && aux[fa[u][L]]) ) L++;
                    while ( R < B && (fa[v][R] != -1 && aux[fa[v][R]]) ) R++;
                    if ( L < B && fa[u][L] == -1 ) L = B;
                    if ( R < B && fa[v][R] == -1 ) R = B;
                }
                if ( L == B && R == B ) break;
                if ( R == B || (L < B && dp[u][L] + 1 > dp[v][R]) ){
                    aux[fa[u][L]] = true;
                    er.pb(fa[u][L]);
                    tmp_[sz] = fa[u][L];
                    tmp[sz++] = dp[u][L] + 1;
                    L++;
                } else{
                    aux[fa[v][R]] = true;
                    er.pb(fa[v][R]);
                    tmp_[sz] = fa[v][R];
                    tmp[sz++] = dp[v][R];
                    R++;
                }
            }
            for ( auto &x: er ){
                aux[x] = false;
            }
            for ( int j = 0; j < B; j++ ){
                dp[v][j] = tmp[j];
                fa[v][j] = tmp_[j];
            }
        }
    }
    vector <int> us(n);
    while ( q-- ){
        int t, y; cin >> t >> y;
        --t;
        vector <int> c(y);
        for ( auto &x: c ){
            cin >> x; --x;
            us[x] = true;
        }
        if ( y + 1 < B ){
            int opt = -1;
            for ( int j = 0; j < B; j++ ){
                if ( dp[t][j] != -1 && !us[fa[t][j]] ){
                    opt = dp[t][j];
                    break;
                }
            }
            cout << opt << ln;
        } else{
            vector <int> dp(n, -1);
            for ( int i = 0; i < n; i++ ){
                if ( !us[i] ) chmax(dp[i], 0LL);
                for ( auto &v: G[i] ){
                    if ( dp[i] != -1 ){
                        chmax(dp[v], dp[i] + 1);
                    }
                }
            }
            cout << dp[t] << ln;
        }
        for ( auto &x: c ){
            us[x] = false;
        }
    }

    cout << '\n';
}

• Subtask 1: 7 / 7
• Subtask 2: 7 / 7
• Subtask 3: 86 / 86