Submission #820088

#	Time	Username	Problem	Language	Result	Execution time	Memory
820088		smirichto	Bitaro’s Party (JOI18_bitaro)	C++17	0 / 100	10 ms	10068 KiB

bitaro

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
#define pb push_back
#define pi pair<int,int>
#define F first
#define S second
#define all(x) (x).begin(), (x).end()
#define alll(x) ((x).begin()+1), (x).end()
#define clean(v) (v).resize(distance((v).begin(), unique(all(v))));
#define yes cout<<"Yes"<<endl;
#define no cout<<"No"<<endl;
#define mod mod
#define endl '\n'
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const ll mod = 998244353;

void io() {
    ios::sync_with_stdio(false);
    cin.tie(NULL);
}

template<class T>
bool ckmax(T &a, const T &b) { return a < b ? a = b, 1 : 0; }

template<class T>
bool ckmin(T &a, const T &b) { return a > b ? a = b, 1 : 0; }

void nop() {
    cout << -1 << endl;
    return;
}

const int N = 1e5+5 , B = 550 ;
vector<int> adj[N] ;
vector<pi> best[N] ;
int vis[N] ;
vector<pi> merge(const vector<pi>& a , const vector<pi>& b)
{
    vector<pi> tmp  ;
    int sa = a.size() , sb = b.size() ;
    int i = 0 , j = 0 ;
    while(tmp.size()<B+3 && i<sa && j<sb){
        if(a[i].F>=b[j].F+1){
            tmp.pb(a[i]) ;
            vis[a[i].S] = 1 ;
            i++ ;
        }
        else{
            tmp.pb(make_pair(b[j].F +1 , b[j].S)) ;
            vis[b[j].S] = 1 ;
            j++ ;
        }
        while(i<sa && vis[a[i].S]) i++ ;
        while(j<sb && vis[b[j].S]) j++ ;
    }
    while(tmp.size()<B+3 && j<sb){
        tmp.pb(make_pair(b[j].F +1 , b[j].S)) ;
        j++ ;
    }
    while(tmp.size()<B+3 && i<sa){
        tmp.pb(a[i]) ;
        i++ ;
    }

    for(auto p : tmp) vis[p.S] = 0 ;
    return tmp ;


}

int marked[N] ;
int ans ;



void solve() {
    int n , m , q ;
    cin>>n>>m>>q ;
    for(int i = 1 ; i<=m ; i++){
        int u , v ;
        cin>>u>>v ;
        assert(u<v) ;
        adj[v].pb(u) ;
    }
    for(int i = 1 ; i<=n ; i++){
        best[i].pb({0 , i}) ;
        for(int to  : adj[i]){
            best[i] = merge(best[i] , best[to]) ;
        }
    }
    while(q--){
        int t , y ;
        cin>>t>>y ;
        vector<int> v ;
        for(int i = 1 ; i<=y ; i++){
            int x ; cin>>x ;
            marked[x] = 1 ;
            v.pb(x) ;
        }
        ans = -1 ;
        if(y<=B){
            for(auto & i : best[t]){
                if(!marked[i.S]){
                    ans = i.F ;
                    break ;
                }
            }
        }
        else{
            queue<pi> q ; q.push({t , 0}) ;
            while(!q.empty()){
                auto p = q.front() ; q.pop() ;
                if(!marked[p.F]) ckmax(ans , p.S) ;
                for(int to : adj[p.F]){
                    q.push({to , p.S + 1}) ;
                }
            }
        }
        cout<<ans<<endl;
        for(int j : v) marked[j] = 0 ;

    }

}

int main() {
#ifndef ONLINE_JUDGE
    freopen("input.in", "r", stdin);
    freopen("output.out", "w", stdout);
#endif
    io();
    ll tt = 1;
    //cin>>tt ;
    while (tt--) {
        solve();
    }

    return 0;
}

Compilation message (stderr)

bitaro.cpp: In function 'int main()':
bitaro.cpp:130:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  130 |     freopen("input.in", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
bitaro.cpp:131:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  131 |     freopen("output.out", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 7
• Subtask 2: 0 / 7
• Subtask 3: 0 / 86