Submission #1023392

#	Time	Username	Problem	Language	Result	Execution time	Memory
1023392		j_vdd16	Closing Time (IOI23_closing)	C++17	8 / 100	94 ms	37968 KiB

closing

#include <algorithm>
#include <bitset>
#include <cstdint>
#include <cstring>
#include <iostream>
#include <limits.h>
#include <math.h>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <vector>

#define int long long
#define loop(X, N) for(int X = 0; X < (N); X++)
#define all(V) V.begin(), V.end()
#define rall(V) V.rbegin(), V.rend()

using namespace std;

typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int, int> ii;
typedef vector<ii> vii;
typedef vector<vector<ii>> vvii;
typedef vector<bool> vb;
typedef vector<vector<bool>> vvb;

vvii adj;
//struct Partition {
//	Partition(int n) : degrees(vi(n)) {}
//
//	set<int> elements;
//	vi degrees;
//	priority_queue<ii, vii, greater<ii>> leaves;
//};

void dfs(int node, int cost, vi& costs, vi& parents) {
	costs[node] = cost;

	for (auto [child, weight] : adj[node]) {
		if (child == parents[node])
			continue;

		parents[child] = node;
		dfs(child, cost + weight, costs, parents);
	}
}

signed max_score(signed n, signed x, signed y, int _k, vector<signed> u, vector<signed> v, vector<signed> w) {
	adj = vvii(n);
	loop(i, n - 1) {
		adj[u[i]].push_back({ v[i], w[i] });
		adj[v[i]].push_back({ u[i], w[i] });
	}

	vi costX(n), parentX(n);
	vi costY(n), parentY(n);
	dfs(x, 0, costX, parentX);
	dfs(y, 0, costY, parentY);

	int maxScore = 0;
	{
		int k = _k;
		typedef tuple<int, int, int> iii;
		priority_queue<iii, vector<iii>, greater<iii>> toAdd;
		vb vis(n);
		toAdd.push({ 0, x, -1 });
		toAdd.push({ 0, y, -1 });

		while (toAdd.size()) {
			auto [cost, node, parent] = toAdd.top();
			toAdd.pop();
			if (k - cost < 0)
				break;

			vis[node] = true;
			k -= cost;
			maxScore++;

			for (auto [child, weight] : adj[node]) {
				if (child == parent || vis[child]) continue;

				toAdd.push({ min(costX[child], costY[child]), child, node });
			}
		}
	}
	{
		//int score = 0;

		//set<int> fixed;
		int border = -1;
		{
			int ptr = y;
			while (ptr != x) {
				if (costX[ptr] < costY[ptr] && border == -1) {
					border = ptr;
					break;
				}

				ptr = parentX[ptr];
			}
		}

		for (int doubleCount = 1; true; doubleCount++) {
			//cout << "Iteration: " << endl;
			int k = _k;

			set<int> added;
			priority_queue<ii, vii, greater<ii>> toAdd;
			toAdd.push({ max(costX[border], costY[border]), border });
			loop(i, doubleCount) {
				if (toAdd.size() == 0)
					return maxScore;

				auto [cost, node] = toAdd.top();
				toAdd.pop();
				added.insert(node);
				k -= cost;
				if (k < 0)
					return maxScore;

				//cout << "Added 1: " << node << endl;

				for (auto [child, weight] : adj[node]) {
					if (added.count(child))
						continue;

					toAdd.push({ max(costX[child], costY[child]), child });
				}
			}

			set<int> newSet;
			while (toAdd.size()) {
				auto [cost, node] = toAdd.top(); toAdd.pop();
				newSet.insert(node);
			}
			for (auto [child, weight] : adj[x])
				if (added.count(child) == 0)
					newSet.insert(child);
			for (auto [child, weight] : adj[y])
				if (added.count(child) == 0)
					newSet.insert(child);

			int addedCount = 0;
			int ptr = x;
			while (added.count(ptr) == 0) {
				newSet.erase(ptr);
				added.insert(ptr);
				k -= costX[ptr];
				addedCount++;

				//cout << "Added 2: " << ptr << endl;


				ptr = parentY[ptr];
			}
			ptr = y;
			while (added.count(ptr) == 0) {
				newSet.erase(ptr);
				added.insert(ptr);
				k -= costY[ptr];
				addedCount++;

				//cout << "Added 2: " << ptr << endl;

				ptr = parentX[ptr];
			}
			if (k < 0)
				return maxScore;

			for (int node : newSet)
				toAdd.push({ min(costX[node], costY[node]), node });

			while (toAdd.size()) {
				auto [cost, node] = toAdd.top();
				toAdd.pop();
				added.insert(node);
				if (k < cost)
					break;

				addedCount++;
				//cout << "Added 3: " << node << endl;

				k -= cost;
				for (auto [child, weight] : adj[node]) {
					if (added.count(child))
						continue;

					toAdd.push({ min(costX[child], costY[child]), child });
				}
			}

			maxScore = max(maxScore, /*score + */2 * doubleCount + addedCount);
		}
	}

	return maxScore;
}

• Subtask 0: 0 / 0
• Subtask 1: 8 / 8
• Subtask 2: 0 / 9
• Subtask 3: 0 / 12
• Subtask 4: 0 / 14
• Subtask 5: 0 / 9
• Subtask 6: 0 / 11
• Subtask 7: 0 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 17