Submission #845986

#	Time	Username	Problem	Language	Result	Execution time	Memory
845986		guagua0407	Bitaro’s Party (JOI18_bitaro)	C++17	100 / 100	1160 ms	117196 KiB

bitaro

#pragma GCC optimize("O3")
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pii pair<int,int>
#define f first
#define s second
#define all(x) x.begin(),x.end()
#define _ ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

void setIO(string s) {
    freopen((s + ".in").c_str(), "r", stdin);
    freopen((s + ".out").c_str(), "w", stdout);
}

const int K=100;
const int mxn=1e5+5;
vector<int> adj[mxn];
vector<pair<int,int> > S[mxn];

int main(){
    ios::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    auto st=clock();
    int n,m,q;
    cin>>n>>m>>q;
    for(int i=0;i<m;i++){
        int a,b;
        cin>>a>>b;
        a--;
        b--;
        adj[b].push_back(a);
    }
    vector<int> mx(n,-1);
    vector<vector<int>> rev(n);
    for(int i=0;i<n;i++){
        vector<int> use;
        use.push_back(i);
        mx[i]=0;
        for(auto v:adj[i]){
            for(auto u:S[v]){
                if(mx[u.s]==-1){
                    use.push_back(u.s);
                }
                mx[u.s]=max(mx[u.s],u.f+1);
            }
        }
        int mxx=0;
        for(auto v:use){
            rev[mx[v]].push_back(v);
            mxx=max(mxx,mx[v]);
        }
        while((int)S[i].size()<K and mxx>=0){
            while(mxx>=0 and rev[mxx].empty()) mxx--;
            if(mxx>=0 and !rev[mxx].empty()){
                S[i].push_back({mxx,rev[mxx].back()});
                rev[mxx].pop_back();
            }
        }
        for(auto v:use){
            rev[mx[v]].clear();
            mx[v]=-1;
        }
    }
    vector<int> ok(n,1);
    for(int i=0;i<q;i++){
        int v;
        cin>>v;
        v--;
        int t;
        cin>>t;
        vector<int> vec(t);
        for(int j=0;j<t;j++){
        	cin>>vec[j];
        	vec[j]--;
        	ok[vec[j]]=0;
        }
        //sort(all(vec));
        if(t>=(int)S[v].size()){
            vector<int> d(n,-1);
            d[v]=0;
            for(int j=v;j>=0;j--){
                if(d[j]==-1) continue;
                for(auto u:adj[j]){
                    d[u]=max(d[u],d[j]+1);
                }
            }
            int ans=-1;
            for(int j=0;j<=v;j++){
                if(ok[j]){
                    ans=max(ans,d[j]);
                }
            }
            cout<<ans<<'\n';
        }
        else{
            bool tf=false;
            for(auto u:S[v]){
                if(ok[u.s]){
                    cout<<u.f<<'\n';
                    tf=true;
                    break;
                }
            }
            assert(tf);
        }
        for(int j=0;j<t;j++){
        	ok[vec[j]]=1;
        }
    }
}

Compilation message (stderr)

bitaro.cpp: In function 'int main()':
bitaro.cpp:24:10: warning: unused variable 'st' [-Wunused-variable]
   24 |     auto st=clock();
      |          ^~
bitaro.cpp: In function 'void setIO(std::string)':
bitaro.cpp:12:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   12 |     freopen((s + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
bitaro.cpp:13:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   13 |     freopen((s + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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