제출 #1033304

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1033304		s_tree	Regions (IOI09_regions)	C++17	80 / 100	5077 ms	131072 KiB

regions

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

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
 
template <typename T> using oset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

#define vt vector
#define rep(i, a, b) for(int i = a; i < (b); ++i)
#define all(x) begin(x), end(x)
#define sz(x) (int)(x).size()
#define pb push_back

typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef vector<int> vi;

template<class T> bool chmin(T& a, const T& b) {
	return b<a?a=b, 1:0;
}
template<class T> bool chmax(T& a, const T& b) { 
	return a<b?a=b, 1:0;
} 
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
mt19937_64 rng_64(chrono::steady_clock::now().time_since_epoch().count());


const int B = 70;
int main() {
	cin.tie(0)->sync_with_stdio(0);
	cin.exceptions(cin.failbit);
	int n, r, q;
	cin >> n >> r >> q;
	vt<vt<int>> g(n+1);
	vt<vt<int>> col(r+1);
	vt<int> c(n+1);
	vt<vt<ll>> precomp(r+1);
	for(int i = 1;i<=n;i++) {
		if(i>1) {
			int par;
			cin >> par;
			g[par].pb(i);
		}
		int h;
		cin >> h;
		c[i] = h;
		col[h].pb(i);
	}
	vt<int> tin(n+1), tout(n+1);
	int timer=0;
	vt<vt<int>> tinCol(n+1);
	vt<vt<int>> toutCol(n+1);
	auto dfs = [&](int at,  auto &&dfs) -> void {
		tin[at]=++timer;	
		tinCol[c[at]].pb(tin[at]);
		for(int to:g[at]) {
			dfs(to, dfs);
		}
		tout[at]=++timer;
		toutCol[c[at]].pb(tout[at]);
	};
	int fixedCol=0;
	auto dfs2 = [&](int at,  auto &&dfs2) -> int {
		int cnt=0;
		for(int to:g[at]) {
			cnt+=dfs2(to, dfs2);
		}
		precomp[fixedCol][c[at]]+=cnt;
		cnt+=(fixedCol==c[at]);
		return cnt;
	};
	dfs(1, dfs);
	for(int i = 1;i<=r;i++) {
		if(sz(col[i])>B) {
			fixedCol=i;
			precomp[i].resize(r+1);
			dfs2(1, dfs2);
		}
	}
	while(q--) {
		int r1, r2;
		cin >> r1 >> r2;
		if(sz(col[r2])>B) {
			cout << precomp[r2][r1] << endl;
		}
		else {
			ll ans=0;
			for(int i:col[r2]) {
				ans+=lower_bound(all(tinCol[r1]), tin[i])-tinCol[r1].begin();
				ans-=lower_bound(all(toutCol[r1]), tin[i])-toutCol[r1].begin();
			}
			cout << ans << endl;
		}
	}

}

• Subtask 1: 15 / 15
• Subtask 2: 65 / 85