Submission #1234492

#	Time	Username	Problem	Language	Result	Execution time	Memory
1234492		PlayVoltz	Regions (IOI09_regions)	C++20	100 / 100	2711 ms	36764 KiB

regions

#include <cstdio>
#include <stdio.h>
#include <stdbool.h>
#include <iostream>
#include <map>
#include <vector>
#include <climits>
#include <stack>
#include <string>
#include <queue>
#include <algorithm>
#include <set>
#include <unordered_set>
#include <unordered_map>
#include <cmath>
#include <cctype>
#include <bitset>
#include <iomanip>
#include <cstring>
#include <numeric>
#include <cassert>
#include <random>
#include <chrono>
#include <fstream>
using namespace std;

#define int long long
#define pii pair<int, int>
#define mp make_pair
#define pb push_back
#define fi first
#define se second

int BLK = 447;

int counter=-1;
vector<int> cc, in, out;
vector<vector<int> > graph, vect, rev, pre;

void dfs(int node, int par){
	in[node]=++counter;
	vect[cc[node]].pb(in[node]);
	rev[cc[node]].pb(node);
	for (auto num:graph[node])if (num!=par)dfs(num, node);
	out[node]=counter;
}

void dfs2(int node, int par, int sum, int r){
	sum+=(cc[node]==r);
	pre[r][cc[node]]+=sum;
	for (auto num:graph[node])if (num!=par)dfs2(num, node, sum, r);
}

int32_t main(){
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	int n, m, q, a, b;
	cin>>n>>m>>q;
	in.resize(n+1);
	out.resize(n+1);
	cc.resize(n+1);
	rev.resize(m+1);
	vect.resize(m+1);
	graph.resize(n+1);
	pre.resize(m+1);
	cin>>cc[1];
	for (int i=2; i<=n; ++i)cin>>a>>cc[i], graph[a].pb(i);
	dfs(1, -1);
	while (q--){
		cin>>a>>b;
		if (vect[a].size()<BLK){
			int ans=0;
			for (auto c:rev[a])ans+=upper_bound(vect[b].begin(), vect[b].end(), out[c])-lower_bound(vect[b].begin(), vect[b].end(), in[c]);
			cout<<ans<<endl;
		}
		else{
			if (pre[a].empty())pre[a].resize(m+1, 0), dfs2(1, -1, 0, a);
			cout<<pre[a][b]<<endl;
		}
	}
}

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