Submission #967473

#	Time	Username	Problem	Language	Result	Execution time	Memory
967473		Tuanlinh123	Bitaro’s Party (JOI18_bitaro)	C++17	100 / 100	869 ms	255128 KiB

bitaro

#include<bits/stdc++.h>
#define ll int
#define pll pair<ll, ll>
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define ld long double
#define sz(a) ((ll)(a).size())
using namespace std;

const ll maxn=100005, s=300;
ll dp[maxn], seen[maxn];
vector <pll> best[maxn];
vector <ll> A[maxn], At[maxn];

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    ll n, m, q; cin >> n >> m >> q;
    for (ll i=1; i<=m; i++)
    {
        ll u, v; cin >> u >> v;
        A[u].pb(v), At[v].pb(u);
    }
    for (ll u=1; u<=n; u++)
    {
        if (sz(At[u]))
        {
            vector <pll> val; 
            best[u]=best[At[u][0]];
            for (ll i=1; i<sz(At[u]); i++)
            {
                val.clear(), val.reserve(s*2);
                ll v=At[u][i];
                for (ll p1=0, p2=0; p1<sz(best[u]) || p2<sz(best[v]);)
                {
                    if (p1==sz(best[u]) || (p2<sz(best[v]) && best[u][p1]<best[v][p2]))
                        val.pb(best[v][p2]), p2++;
                    else val.pb(best[u][p1]), p1++;
                }
                best[u].clear();
                for (auto [x, v]:val)
                    if (!seen[v])
                    {
                        seen[v]=1, best[u].pb({x, v});
                        if (sz(best[u])==s) break;
                    }
                for (auto [x, v]:best[u]) seen[v]=0;
            }
        }
        for (auto &[x, v]:best[u]) x++;
        if (sz(best[u])<s) best[u].pb({0, u});
    }
    for (ll i=1; i<=q; i++)
    {
        ll X, x, ans=-1; cin >> X >> x;
        vector <ll> a(x);
        for (ll &i:a) cin >> i, seen[i]=1;
        if (x>=s)
        {
            for (ll i=1; i<=n; i++) dp[i]=seen[i]?-1e9:0;
            for (ll u=1; u<=X; u++)
                for (ll v:At[u]) 
                    dp[u]=max(dp[u], dp[v]+1);
            if (dp[X]>=0) ans=dp[X];
        }
        else for (auto [x, v]:best[X])
            if (!seen[v]) {ans=x; break;}
        for (ll j:a) seen[j]=0;
        cout << ans << "\n";
    }
}

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