Submission #1041908

#	Time	Username	Problem	Language	Result	Execution time	Memory
1041908		42kangaroo	Closing Time (IOI23_closing)	C++17	43 / 100	86 ms	46264 KiB

closing

#include "closing.h"
#include "bits/stdc++.h"

#define ll long long
using namespace std;

struct Ed {
	ll to, w;
};

bool operator<(const Ed &l, const Ed &r) {
	return l.w > r.w;
}

using g_t = vector<vector<Ed>>;

void diDfs(int n, ll d, g_t &g, vector<ll> &di) {
	if (di[n] != -1) return;
	di[n] = d;
	for (auto e: g[n]) {
		diDfs(e.to, d + e.w, g, di);
	}
}

void maG(int n, int p, bool com, g_t &g, g_t &nG, vector<bool> &ma, array<vector<ll>, 2> &di, vector<int> &inD) {
	if (!ma[n]) {
		if (di[com][p] == 0) {
			nG.back().push_back({n, di[com][n]});
			inD[n]++;
		} else if (di[com][n] < di[!com][n] || (di[com][n] == di[!com][n] && com)) {
			nG[p].push_back({n, di[com][n]});
			inD[n]++;
		} else {
			nG[n].push_back({n + (int) g.size(), di[com][n] - di[!com][n]});
			nG[p + g.size()].push_back({n + (int) g.size(), di[com][n] - di[!com][n]});
			inD[n + g.size()] += 2;
		}
	} else if (ma[n] && di[com][n] > di[!com][n]) {
		if (di[com][p] <= di[!com][p]) {
			nG.back().push_back({n + (int) g.size(), di[com][n] - di[!com][n]});
			inD[n + g.size()]++;
		} else {
			nG[p + g.size()].push_back({n + (int) g.size(), di[com][n] - di[!com][n]});
			inD[n + g.size()]++;
		}
	}
	for (auto e: g[n]) {
		if (e.to == p) continue;
		maG(e.to, n, com, g, nG, ma, di, inD);
	}
}

bool markdfs(int n, int p, int y, g_t &g, vector<bool> &ma) {
	if (n == y) return ma[n] = true;
	for (auto e: g[n]) {
		if (e.to == p) continue;
		if (markdfs(e.to, n, y, g, ma)) return ma[n] = true;
	}
	return false;
}

int max_score(int N, int X, int Y, long long K,
              std::vector<int> U, std::vector<int> V, std::vector<int> W) {
	g_t g(N);
	for (int i = 0; i < N - 1; ++i) {
		g[U[i]].push_back({V[i], W[i]});
		g[V[i]].push_back({U[i], W[i]});
	}
	array<vector<ll>, 2> dist;
	dist.fill(vector<ll>(N, -1));
	diDfs(X, 0, g, dist[0]);
	diDfs(Y, 0, g, dist[1]);
	int nuWithout = 0;
	vector<bool> vis(N, false);
	priority_queue<pair<Ed, bool>> q;
	q.push({{X, 0}, false});
	q.push({{Y, 0}, true});
	ll kC = K;
	while (!q.empty()) {
		auto [ed, com] = q.top();
		q.pop();
		if (vis[ed.to]) continue;
		if (kC < ed.w) break;
		kC -= ed.w;
		nuWithout++;
		vis[ed.to] = true;
		for (auto e: g[ed.to]) {
			q.push({{e.to, dist[com][e.to]}, com});
		}
	}
	vector<bool> ma(N, false);
	markdfs(X, X, Y, g, ma);
	int nuW = 0;
	g_t nG(2 * N + 1);
	for (int i = 0; i < N; ++i) {
		if (ma[i]) {
			K -= min(dist[0][i], dist[1][i]);
			nuW++;
			if (dist[0][i] == dist[1][i]) nuW++;
		}
	}
	if (K < 0) return nuWithout;
	vector<int> inD(2 * N);
	maG(X, X, false, g, nG, ma, dist, inD);
	maG(Y, Y, true, g, nG, ma, dist, inD);
	q.push({{2 * N, 0}, false});
	while (!q.empty()) {
		auto [ed, com] = q.top();
		q.pop();
		if (K < ed.w) break;
		K -= ed.w;
		if (com) nuW++;
		for (auto e: nG[ed.to]) {
			if (--inD[e.to] == 0) {
				q.push({e, true});
			}
		}
	}
	return max(nuW, nuWithout);
}

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