Submission #1286561

#	Time	Username	Problem	Language	Result	Execution time	Memory
1286561		quocbaoo	Bitaro’s Party (JOI18_bitaro)	C++20	100 / 100	1041 ms	477356 KiB

bitaro

#include<bits/stdc++.h>
#define fi first
#define se second
#define ll long long
using namespace std;
const int S=336,N=1e5;
int dp[100005],a[N+5];bool dd[100005];
vector<int> g[N+5],gn[N+5];
vector<pair<int,int>> vec[N+5];
bool cmp(pair<int,int> u1,pair<int,int> v1){
    return u1.se>v1.se;
}
int main(){
    if (fopen("bitaro.inp","r")){
        freopen("bitaro.inp","r",stdin);
        freopen("bitaro.out","w",stdout);
    }
    ios_base::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
    int n,m,q;cin>>n>>m>>q;
    for (int i=1;i<=m;i++){
        int u,v;cin>>u>>v;
        g[u].push_back(v);
        gn[v].push_back(u);
    }
    for (int i=1;i<=n;i++){
        vector<pair<int,int>> lu1;
        lu1.push_back({i,0});
        for (auto j:gn[i]){
            vector<pair<int,int>> lu;
            for (auto k:vec[j]){
                lu.push_back({k.fi,k.se+1});
            }
            vec[i].clear();
            vec[i].resize(lu.size()+lu1.size());
            merge(lu.begin(),lu.end(),lu1.begin(),lu1.end(),vec[i].begin(),cmp);
            lu1.clear();
            int dem=0;
            for (auto j:vec[i]){
                if (dd[j.fi]) continue;
                dd[j.fi]=true;
                lu1.push_back({j.fi,j.se});dem++;if (dem>S) break;
            }
            for (auto j:lu1) dd[j.fi]=false;
        }
        vec[i].clear();
        for (auto j:lu1) vec[i].push_back({j.fi,j.se});
    }
    while (q--){
        int u,k;cin>>u>>k;
        for (int i=1;i<=k;i++) cin>>a[i];
        for (int i=1;i<=k;i++) dd[a[i]]=true;
        if (k<S){
            bool kt=false;
            for (auto j:vec[u]) {
                if (dd[j.fi]==false) {
                    cout<<j.se<<'\n';kt=true;break;
                }
            }
            if (kt==false) cout<<"-1"<<'\n';
        }
        else{
            int ma=-1;
            for (int i=1;i<=n;i++) dp[i]=-1e9;
            dp[u]=0;
            for (int i=u-1;i>=1;i--){
                for (auto j:g[i]){
                    dp[i]=max(dp[i],dp[j]+1);
                }
            }
            for (int i=1;i<=u;i++){
                if (dd[i]==false) ma=max(ma,dp[i]);
            }
            cout<<ma<<'\n';
        }
        for (int i=1;i<=k;i++) dd[a[i]]=false;
    }
}

Compilation message (stderr)

bitaro.cpp: In function 'int main()':
bitaro.cpp:15:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   15 |         freopen("bitaro.inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
bitaro.cpp:16:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   16 |         freopen("bitaro.out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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