Submission #883344

#	Time	Username	Problem	Language	Result	Execution time	Memory
883344		serifefedartar	Regions (IOI09_regions)	C++17	30 / 100	1357 ms	50600 KiB

regions

#include <bits/stdc++.h>
using namespace std;

#define fast ios::sync_with_stdio(0);cin.tie(0);
#define s second
#define f first
typedef long long ll;
const ll MOD = 1e9 + 9;
const ll LOGN = 21;
const ll MAXN = 2e5 +  100;

vector<vector<int>> graph;
int reg[MAXN], dp[505][505];
vector<int> cnt[MAXN], Rin[25100], Rout[25100];
map<pair<int,int>, pair<int,bool>> memo;

void dfs(int node, int parent) {
	cnt[node][reg[node]]++;
	for (int reg_other = 1; reg_other <= 500; reg_other++)
		dp[reg_other][reg[node]] += cnt[node][reg_other];
	for (auto u : graph[node]) {
		swap(cnt[u], cnt[node]);
		dfs(u, node);
	}
	cnt[node][reg[node]]--;
	swap(cnt[parent], cnt[node]);
}
	
int T = 0;
int tin[MAXN], tout[MAXN];
void dfs2(int node, int parent) {
	tin[node] = ++T;
	Rout[reg[node]].push_back(tin[node]);
	for (auto u : graph[node])
		dfs2(u, node);
	tout[node] = T;
	Rout[reg[node]].push_back(tin[node]);
}

int main() {
	fast
	int N, R, Q, a, b;
	cin >> N >> R >> Q;

	graph = vector<vector<int>>(N+1, vector<int>());
	cin >> reg[1];
	for (int i = 2; i <= N; i++) {
		int S;
		cin >> S >> reg[i];
		graph[S].push_back(i);
	}

	if (R <= 500) {
		cnt[1] = vector<int>(505, 0);
		dfs(1, 1);
		for (int i = 0; i < Q; i++) {
			cin >> a >> b;
			cout << dp[a][b] << endl;
		}
	} else {
		dfs2(1, 1);
		for (int i = 0; i < Q; i++) {
			cin >> a >> b;
			if (memo[{a, b}].s == false) {
				int ans;
				if (Rin[a].size() < Rin[b].size())
					ans = (upper_bound(Rin[b].begin(), Rin[b].end(), tout[a]) - Rin[b].begin()) - (lower_bound(Rin[b].begin(), Rin[b].end(), tin[a]) - Rin[b].begin());
				else {
					
				}
				memo[{a, b}] = {ans, 1};
			}
			cout << memo[{a, b}].f << endl;
		}
	}
}

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