Submission #945462

#	Time	Username	Problem	Language	Result	Execution time	Memory
945462		mc061	Regions (IOI09_regions)	C++14	100 / 100	5437 ms	124472 KiB

regions

#include <bits/stdc++.h>
using namespace std;
#ifdef ONLINE_JUDGE
    #include "debug.h"
#else
	#pragma GCC optimize("O3")
	#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
    #define dbg(...) 42
    template<typename T>ostream&operator<<(ostream&os,vector<T>&vec){for(signed i=0;i+1<vec.size();++i){os<<vec[i]<<" ";}if(vec.size()>0)os<<vec.back();return os;}
#endif

const int N = 2e5 + 6;	
const int R = 25001;
int n;

int col[N];
int tin[N], tout[N];
vector<int> tree[N], tour;
void build_tour(int v, int p=-1) {
	tour.push_back(v);
	tin[v] = tour.size() - 1;
	for (int u : tree[v]) if (u != p) {
		build_tour(u, v);
	}
	tout[v] = tour.size() - 1;
}
vector<pair<int, int>> seg[2 * N];
int get_node_count(const vector<pair<int, int>>& node, const int& element) {
	auto it = lower_bound(node.begin(), node.end(), make_pair(element, -1));
	if (it == node.end() || it->first != element) return 0;
	return it->second;
}
void combine(vector<pair<int, int>>& dest, const vector<pair<int, int>>& v1, const vector<pair<int, int>>& v2) {
	int p1 = 0, p2 = 0;
	while (p1 < v1.size() && p2 < v2.size()) {
		if (v1[p1].first < v2[p2].first) dest.push_back(v1[p1++]);
		else if (v2[p2].first < v1[p1].first) dest.push_back(v2[p2++]);
		else if (v1[p1].first == v2[p2].first) dest.emplace_back(v1[p1].first, v1[p1].second + v2[p2].second), ++p1, ++p2;
	}
	while (p1 < v1.size()) dest.push_back(v1[p1++]);
	while (p2 < v2.size()) dest.push_back(v2[p2++]);
}
void build() {
	for (int i = 0; i < n; ++i) {
		seg[n + i].push_back({col[tour[i]], 1});
	}
	for (int i = n - 1; i > 0; --i) {
		combine(seg[i], seg[i << 1], seg[i << 1 | 1]);
	}
}

const int BLOCK = 160;
int cnt[N / BLOCK][R] = {};
vector<int> comp[R];
int bigindex[N] = {};

signed main(void) {
    cin.tie(0)->sync_with_stdio(false);

	int r, q;
	cin >> n >> r >> q;
	cin >> col[1];
	--col[1];
	comp[col[1]].push_back(1);
	for (int i = 2; i <= n; ++i) {
		int p;
		cin >> p >> col[i];
		--col[i];
		comp[col[i]].push_back(i);
		tree[p].push_back(i);
		tree[i].push_back(p);
	}
	build_tour(1);
	build();
	int index = 0;
	for (int i = 0; i < r; ++i) {
		if (comp[i].size() >= BLOCK) {
			int cnt_now = 0;
			bigindex[i] = index;
			function<void(int, int)> dfs = [&] (int v, int p) -> void {
				if (col[v] == i) ++cnt_now;
				else cnt[index][col[v]] += cnt_now;
				for (int u : tree[v]) if (u != p) {
					dfs(u, v);
				}	
				if (col[v] == i) --cnt_now;
			};
			dfs(1, 1);
			++index;
		}
	}
	while (q--) {
		int a, b;
		cin >> a >> b;
		--a, --b;
		if (comp[a].size() >= BLOCK) {
			cout << cnt[bigindex[a]][b] << endl;
			continue;
		}
		int ans = 0;
		for (int v : comp[a]) {
			int tl = tin[v] + n, tr = tout[v] + n + 1;
			for (; tl < tr; tl >>= 1, tr >>= 1) {
				if (tl&1) ans += get_node_count(seg[tl], b), ++tl;
				if (tr&1) --tr, ans += get_node_count(seg[tr], b);
			}
		}
		cout << ans << endl;
	}
}

Compilation message (stderr)

regions.cpp: In function 'void combine(std::vector<std::pair<int, int> >&, const std::vector<std::pair<int, int> >&, const std::vector<std::pair<int, int> >&)':
regions.cpp:35:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   35 |  while (p1 < v1.size() && p2 < v2.size()) {
      |         ~~~^~~~~~~~~~~
regions.cpp:35:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   35 |  while (p1 < v1.size() && p2 < v2.size()) {
      |                           ~~~^~~~~~~~~~~
regions.cpp:40:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   40 |  while (p1 < v1.size()) dest.push_back(v1[p1++]);
      |         ~~~^~~~~~~~~~~
regions.cpp:41:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   41 |  while (p2 < v2.size()) dest.push_back(v2[p2++]);
      |         ~~~^~~~~~~~~~~

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