Submission #983161

#	Time	Username	Problem	Language	Result	Execution time	Memory
983161		feev1x	Cyberland (APIO23_cyberland)	C++17	13 / 100	38 ms	8760 KiB

cyberland

#include "cyberland.h"

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

const double INF = numeric_limits<double>::max();

double nonol(vector<vector<pair<int, int>>> g, int N, int M, int K, int H, vector<int> arr) {
	vector<bool> used(N), ot(N);
	function<void(int, int)> dfs = [&](int v, int cnt) {
		assert(!used[v]);
		used[v] = true;
		for (auto [to, weight]: g[v]) {
			if (!used[to]) {
				if (arr[to] == 2 && cnt) {
					ot[to] = true;
					dfs(to, cnt - 1);
				} else dfs(to, cnt);
			}
		}
	};
	vector<double> d(N + 1, INF);
	d[0] = 0;
	set<pair<double, int>> q;
	q.emplace(d[0], 0);
	while (!q.empty()) {
		int nearest = q.begin()->second;
		q.erase(q.begin());
		for (auto [to, weight]: g[nearest]) {
			double dis = d[nearest] + weight;
			if (ot[to]) dis /= 2;
			if (!arr[to]) dis = 0;
			if (d[to] > dis) {
				q.erase(pair{d[to], to});
				d[to] = dis;
				q.emplace(d[to], to);
			}
		}
	}
        if (d[H] == INF) d[H] = -1;
	return d[H];
}

double s1(vector<vector<pair<int, int>>> g, int N, int M, int K, int H, vector<int> arr) {
	double dis = INF;
	bool can = false;
	double zap;
	int u;
	for (auto [to, weight]: g[0]) {
		if (to == H) {
			dis = fmin(dis, weight);
		} else can = true, zap = weight, u = to;
	}
	if (can) {
		double w;
		can = false;
		for (auto [to, weight]: g[u]) {
			if (to == H) can = true, w = weight;
		}
		if (can) {
			if (arr[u] == 0) dis = fmin(dis, w);
			else if (arr[u] == 1) dis = fmin(dis, w + zap);
			else dis = fmin(dis, zap / 2. + w);
		}
	}
	if (dis == INF) dis = -1;
	return dis;
}

double s4(std::vector<int> x, std::vector<int> y, std::vector<int> c, int N, int M, int K, int H, vector<int> arr) {
	vector<bool> ot(N);
	int cnt = K;
	for (int i = H - 1; i > 0; --i) {
		if (arr[i] == 2 && cnt) cnt--, ot[i] = true;
	}
	cnt = K;
	for (int i = H + 1; i < N; ++i) {
		if (arr[i] == 2 && cnt) cnt--, ot[i] = true;
	}
	double dis = INF;
	double tmp = 0;
	for (int i = 0; i < H; ++i) {
		tmp += c[i];
		if (arr[i + 1] == 0) tmp = 0;
		if (arr[i + 1] == 2) tmp /= 2;
	}
	dis = tmp;
	tmp = 0;
	bool flag = false;
	for (int i = N - 1; i > H; --i) {
		tmp += c[i - 1];
		if (arr[i - 1] == 0) tmp = 0, flag = true;
		if (arr[i - 1] == 2) tmp /= 2;
	}
	if (flag) dis = min(dis, tmp);
	if (dis == INF) dis = -1;
	return dis;
}
double yesnol(vector<vector<pair<int, int>>> g, int N, int M, int K, int H, vector<int> arr) {return -1;}

double solve(int N, int M, int K, int H, std::vector<int> x, std::vector<int> y, std::vector<int> c, std::vector<int> arr) {
    vector<vector<pair<int, int>>> g(N);
    bool is2 = true;
    for (int i = 0; i < M; ++i) {
		g[x[i]].emplace_back(y[i], c[i]);
		g[y[i]].emplace_back(x[i], c[i]);
		if (x[i] != i + 1 || y[i] != i + 2) is2 = false;
	}
	if (N <= 3) return s1(g, N, M, K, H, arr);
	else if (is2) return s4(x, y, c, N, M, K, H, arr);
	else if (find(arr.begin(), arr.end(), 0LL) == arr.end()) return nonol(g, N, M, K, H, arr);
	else return yesnol(g, N, M, K, H, arr);
}

• Subtask 1: 5 / 5
• Subtask 2: 8 / 8
• Subtask 3: 0 / 13
• Subtask 4: 0 / 19
• Subtask 5: 0 / 7
• Subtask 6: 0 / 16
• Subtask 7: 0 / 29
• Subtask 8: 0 / 3