Submission #958004

#	Time	Username	Problem	Language	Result	Execution time	Memory
958004		tosivanmak	Regions (IOI09_regions)	C++17	85 / 100	6380 ms	131072 KiB

regions

#include<bits/stdc++.h>
using namespace std;
#define ll int
#define pb push_back
const ll B=500;
vector<ll>adj[220005];
bool vis[220005];
ll siz[220005],dep[220005];
ll rem[220005];
bool used[220005];
vector<ll>compo[220005];
int fa[220005];
ll inside[220005];
ll tin[220005],tout[220005];
ll disc[250005];
vector<ll>reg[25005];
vector<ll>blk[455];
ll timer=1;
map<pair<ll,ll>,bool>hv;
map<pair<ll,ll>,ll>ans;
ll ass;
void dfs(ll s){
    vis[s]=1;
    siz[s]=1;
    tin[s]=timer++;
    for(auto& u: adj[s]){
      if(!vis[u]){
          dep[u]=dep[s]+1;
          fa[u]=s;
          dfs(u);
          siz[s]+=siz[u];
      }
    }
    tout[s]=timer;
}
void create(ll s){
    if(used[s])return;
    used[s]=1;
    inside[s]=ass;
    for(auto& u: adj[s]){
        if(!used[u]){
            create(u);
        }
    }
}
struct node{
    ll id,dep;
    bool operator<(const node& n)const{
        return dep<n.dep;
    }
    node(ll _id, ll _dep){
        id=_id,dep=_dep;
    }
};
ll cnt[455][25005];
ll tot[455][25005];
ll store[455];

ll home[200005];
ll anc(ll u, ll v){
    return ((tin[u]<=tin[v])&&(tout[u]>=tout[v])&&(u!=v));
}
vector<node>revdep;
int main(){
    ll n,r,q;
    cin>>n>>r>>q;

    for(int i=1;i<=n;i++){
        if(i==1){
            cin>>home[i];
            reg[home[i]].pb(i);
        }
        else{
            ll con;
            cin>>con;
            adj[con].push_back(i);
            cin>>home[i];
            reg[home[i]].pb(i);
        }
    }
    ass=n+1;
    dfs(1);
    for(int i=1;i<=n;i++){
        inside[i]=i;
        revdep.pb(node(i,dep[i]));
    }
    sort(revdep.rbegin(),revdep.rend());
    for(int i=0;i<revdep.size();i++){
        ll s=revdep[i].id;
        rem[s]=1;
        for(auto& u: adj[s]){
            rem[s]+=rem[u];
        }
        ll sz=0;
        vector<ll>cur;
        for(auto& u: adj[s]){
            sz+=rem[u];
            cur.pb(u);
            if(sz>=B){
                rem[s]-=sz;
                sz=0;
                for(auto& k: cur){
                    create(k);
                }
                fa[ass]=s;
                ass++;
                cur.clear();
            }
        }
        if(s==1){
            for(auto& k: cur){
                    create(k);
                }
                fa[ass]=s;
                ass++;
                cur.clear();
        }
    }
    vector<ll>lis;
    for(int i=1;i<=n;i++){
        lis.pb(inside[i]);
    }
    for(int i=1;i<=n;i++){
        compo[inside[i]].pb(i);
    }
    sort(lis.begin(),lis.end());
    lis.erase(unique(lis.begin(),lis.end()),lis.end());
    for(int i=0;i<lis.size();i++){
        disc[lis[i]]=i+1;
    }
    
    for(int i: lis){
        for(auto& u: compo[i]){
            cnt[disc[i]][home[u]]++;
        }
    }
    for(int i=1;i<=n;i++){
        adj[i].clear();
    }
    for(auto& u: lis){
        compo[u].clear();
    }
    fa[1]=0;
    for(auto& u: lis){
        int popo=fa[u];
        // cout<<popo<<" ";
        while(popo!=1&&popo!=0){
            // cout<<popo<<" ";
            tot[disc[u]][home[popo]]++;
            popo=fa[popo];
        }
        if(popo==0)continue;
        tot[disc[u]][home[popo]]++;
    }
    while(q--){
        ll a,b;
        cin>>a>>b;
        if(hv[{a,b}]){cout<<ans[{a,b}]<<'\n';continue;};
        ll an=0;
        for(auto& u: reg[b]){
            blk[disc[inside[u]]].pb(u);
        }
        for(auto& u: reg[a]){
            for(auto& k: blk[disc[inside[u]]]){
                if(anc(u,k)){
                    an++;
                }
            }
        }
        for(auto& u: reg[b]){
            blk[disc[inside[u]]].clear();
        }
        ll first=0;
        for(auto& u: lis){
            first+=tot[disc[u]][a]*cnt[disc[u]][b];
        }
        hv[{a,b}]=1,ans[{a,b}]=first+an;
        cout<<first+an<<endl;
    }
}

Compilation message (stderr)

regions.cpp: In function 'int main()':
regions.cpp:88:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<node>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   88 |     for(int i=0;i<revdep.size();i++){
      |                 ~^~~~~~~~~~~~~~
regions.cpp:128:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  128 |     for(int i=0;i<lis.size();i++){
      |                 ~^~~~~~~~~~~

• Subtask 1: 15 / 15
• Subtask 2: 70 / 85