# | 제출 시각 | 아이디 | 문제 | 언어 | 결과 | 실행 시간 | 메모리 |
---|---|---|---|---|---|---|---|
871472 | Matjaz | Regions (IOI09_regions) | C++14 | 0 ms | 0 KiB |
이 제출은 이전 버전의 oj.uz에서 채점하였습니다. 현재는 제출 당시와는 다른 서버에서 채점을 하기 때문에, 다시 제출하면 결과가 달라질 수도 있습니다.
//
// IOI09Regions.cpp
//
//
// Created by Matjaz Leonardis on 10/11/2023.
//
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int N,R,Q;
vector<vector<int> > s; // O(N)
vector<vector<int> > region_members; //O(N)
vector<int> H, S; // O(N)
vector<vector<int> > chain; // O(R * N)
vector<vector<int> > answer;
int time1 = 0;
vector<int> start; // O(N)
vector<int> end1; // O(N)
vector<bool> isBigRegion;
vector<int> bigRegionID;
int bigRegions = 0;
void compute_times(int x){
start[x] = time1;
time1++;
for (int i=0;i<s[x].size();i++){
compute_times(s[x][i]);
}
end1[x] = time1;
time1++;
}
void compute_bigregion_sums(int x) {
if (S[x] != -1){
chain[x] = chain[S[x]];
if (bigRegionID[H[S[x]]] != -1) chain[x][bigRegionID[H[S[x]]]]++;
}
if (bigRegionID[H[x]] != -1){
for (int i=0;i<bigRegions;i++) answer[i][bigRegionId[H[x]]] += chain[x][i];
}
for (int i=0;i<s[x].size();i++) compute_bigregion_sums(s[x][i]);
}
int main(){
cin >> N >> R >> Q;
H.assign(N, 0);
S.assign(N, 0);
region_members.assign(R, vector<int>());
for (int i=0;i<N;i++){
if (i == 0) cin >> H[i]; else
cin >> S[i] >> H[i];
S[i]--;
H[i]--;
region_members[H[i]].push_back(i);
}
s.assign(N, vector<int> ());
for (int i=1;i<N;i++) s[S[i]].push_back(i);
isBigRegion.assign(R, false);
bigRegionID.assign(R, -1);
for (int i=0;i<R;i++) isBigRegion[i] = region_members[i].size() > 500;
for (int i=0;i<R;i++) if (isBigRegion[i]){
bigRegionID[i] = bigRegions;
bigRegions++;
}
answer.assign(bigRegions, vector<int> (bigRegions));
chain.assign(N, vector<int> (bigRegions));
compute_bigregion_sums(0);
start.assign(N, -1);
end1.assign(N, -1);
compute_times(0);
vector<vector<int> > tmp(R, vector<int>()); // O(N)
for (int i=0;i<R;i++){
for (int j=0;j<region_members[i].size();j++) tmp[i].push_back(start[region_members[i][j]]);
sort(tmp[i].begin(), tmp[i].end());
}
for (int q=0;q<Q;q++){
int r1,r2;
cin >> r1 >> r2;
r1--;r2--;
int total = 0;
if (!isBigRegion[r1]){
for (int i=0;i<region_members[r1].size();i++){
int e1 = region_members[r1][i];
int strt = lower_bound(tmp[r2].begin(), tmp[r2].end(), start[e1]) - tmp[r2].begin();
int nd = lower_bound(tmp[r2].begin(), tmp[r2].end(), end1[e1]) - tmp[r2].begin();
total += nd - strt;
}
} else if (isBigRegion[r2]){
total = answer[r1][r2];
} else {
for (int i=0;i<region_members[r2].size();i++){
int e2 = region_members[r2][i];
total += chain[e2][bigRegionID[r1]];
}
}
cout << total << endl;
}
return 0;
}