Submission #1051028

#	Time	Username	Problem	Language	Result	Execution time	Memory
1051028		Ludissey	Regions (IOI09_regions)	C++17	75 / 100	8060 ms	131072 KiB

regions

#include <bits/stdc++.h>
#define sz(a) (int)a.size()
#define all(a) a.begin(), a.end()
 
using namespace std;

vector<vector<int>> child;
vector<int> parent;
vector<vector<int>> up;
vector<vector<int>> down;
unordered_map<int,int> conv;
vector<int> rg;
vector<vector<int>> pr;
int need;
int sq;
vector<int> tin;
vector<int> out;
int timer=0;


vector<int> setup_down(int x){
    vector<int> cv(sq);
    for (auto u : child[x]) {
        vector<int> v=setup_down(u);
        for (int i=0; i<sq; i++)
        {
            down[conv[rg[x]]][i]+=v[i];
            cv[i]+=v[i];
        }
    }
    if(conv[rg[x]]<sq){
        down[conv[rg[x]]][conv[rg[x]]]++;
        cv[conv[rg[x]]]++;
    }
    return cv;
}

void setup_up(int x, vector<int> rm){
    for (int i=0; i<sz(rm); i++)
    {
        up[conv[rg[x]]][i]+=rm[i];
    }
    if(conv[rg[x]]<sq){
        up[conv[rg[x]]][conv[rg[x]]]++;
        rm[conv[rg[x]]]++;
    }
    for (auto u : child[x]) setup_up(u,rm);
    return;
}

void setup_euler(int x){
    tin[x]=timer++;
    for (auto u : child[x]) setup_euler(u);
    out[x]=timer++;
}

signed main() {
    ios_base::sync_with_stdio(false); cin.tie(nullptr);
    int N,R,Q; cin >> N >> R >> Q;
    sq=sqrt(R);
    child.resize(N);
    parent.resize(N);
    up.resize(R,vector<int>(sq));
    down.resize(R,vector<int>(sq));
    rg.resize(N);
    tin.resize(N);
    out.resize(N);
    pr.resize(R);
    cin >> rg[0]; rg[0]--;
    vector<pair<int,int>> cnt(R);
    pr[rg[0]].push_back(0);
    cnt[rg[0]].first++;
    for (int i = 1; i < N; i++)
    {
        cin >> parent[i] >> rg[i]; parent[i]--; rg[i]--;
        child[parent[i]].push_back(i);
        pr[rg[i]].push_back(i);
        cnt[rg[i]].first++;
    }
    for (int i = 0; i < R; i++) cnt[i].second=i;
    
    sort(all(cnt),[&](auto &aa, auto &bb){return aa>bb; });
    for (int i = 0; i < sz(cnt); i++)
    {
        conv[cnt[i].second]=i;
    }
    vector<int> ep(sq);
    timer=0;
    setup_euler(0);
    setup_up(0,ep);
    setup_down(0);
    for (int i = 0; i < Q; i++)
    {
        int sm=0;
        int e1,e2; cin >> e1>>e2; e1--; e2--;
        if(conv[e1]<sq){
            sm=up[conv[e2]][conv[e1]];
        }else if(conv[e2]<sq) {
            sm=down[conv[e1]][conv[e2]];
        }else{

            vector<pair<int,pair<int,int>>> tos;
            vector<int> forCONV;
            unordered_map<int,int> conv2;
            for (int j = 0; j < sz(pr[e1]); j++)
            {
                int in1=tin[pr[e1][j]], out1=out[pr[e1][j]];
                forCONV.push_back(in1);
                forCONV.push_back(out1);
            }   
            for (int j = 0; j < sz(pr[e2]); j++)
            {
                int in1=tin[pr[e2][j]], out1=out[pr[e2][j]];
                forCONV.push_back(in1);
                forCONV.push_back(out1);
            }
            sort(all(forCONV));
            for (int j = 0; j < sz(forCONV); j++)
            {
                conv2[forCONV[j]]=j;
            }
            
            for (int j = 0; j < sz(pr[e1]); j++)
            {
                int in1=tin[pr[e1][j]], out1=out[pr[e1][j]];
                tos.push_back({conv2[in1],{conv2[out1],1}});
            }   
            for (int j = 0; j < sz(pr[e2]); j++)
            {
                int in1=tin[pr[e2][j]], out1=out[pr[e2][j]];
                tos.push_back({conv2[in1],{conv2[out1],2}});
            }
            sort(all(tos));
            vector<int> t;
            t.resize(sz(forCONV)*2+1,0);
            int ones=0;
            for (int j = 0; j < sz(tos); j++)
            {
                if(tos[j].second.second==1) {
                    ones++;
                    int p=tos[j].second.first;
                    int value=1;
                    for (t[p += sz(forCONV)] = value; p > 1; p >>= 1) t[p>>1] = t[p] + t[p^1];
                }
                else{
                    int csum=0;
                    int l=0;
                    int r=tos[j].second.first+1;
                    for (l += sz(forCONV), r += sz(forCONV); l < r; l >>= 1, r >>= 1) {
                        if (l&1) csum += t[l++];
                        if (r&1) csum += t[--r];
                    }
                    sm+=ones-csum;
                }
            }
        }
        cout << sm << endl;
    }
    
    return 0;
}

• Subtask 1: 15 / 15
• Subtask 2: 60 / 85