Submission #749139

#	Time	Username	Problem	Language	Result	Execution time	Memory
749139		gun_gan	Cyberland (APIO23_cyberland)	C++17	44 / 100	3073 ms	8988 KiB

cyberland

#include <bits/stdc++.h>
#include "cyberland.h"
using namespace std;
typedef long long ll;

double solve(int N, int M, int K, int H, vector<int> x, vector<int>
y, vector<int> c, vector<int> arr) {
	vector<vector<pair<int,int>>> g(N);
	for(int i = 0; i < M; i++) {
		g[x[i]].push_back({y[i], c[i]});
		g[y[i]].push_back({x[i], c[i]});
	}
	priority_queue<pair<double,int>> pq;

	vector<double> d(N, 1e18), dd(N, 1e18);
	
	{
		dd[0] = 0;
		pq.push({0, 0});

		while(!pq.empty()) {
			auto [x, v] = pq.top(); pq.pop();
			x = -x;
			if(dd[v] < x) continue;
			for(auto [u, w] : g[v]) {
				if(dd[u] > x + w && u != H) {
					dd[u] = x + w;
					pq.push({-dd[u], u});
				}
			} 
		}
	}

	arr[0] = 0;
	for(int i = 0; i < N; i++) if(!arr[i] && dd[i] == 1e18) arr[i] = 1;

	{
		for(int i = 0; i < N; i++) {
			if(!arr[i] && dd[i] != 1e18) {
				d[i] = 0;
				pq.push({0, i});
			}
		}

		while(!pq.empty()) {
			auto [x, v] = pq.top(); pq.pop();
			x = -x;
			if(d[v] < x) continue;
			for(auto [u, w] : g[v]) {
				if(d[u] > x + w && u != H) {
					d[u] = x + w;
					pq.push({-d[u], u});
				}
			} 
		}
	}


	double res = 1e18;

	for(auto [u, w] : g[H]) {
		res = min(res, d[u] + w);
	}

	for(int k = 1; k <= K; k++) {
		vector<double> nd(N, 1e18);

		for(int i = 0; i < N; i++) {
			nd[i] = d[i];
			if(arr[i] == 2 && nd[i] != 1e18) nd[i] /= 2;
			if(nd[i] != 1e18) pq.push({-nd[i], i});
		}

		while(!pq.empty()) {
			auto [x, v] = pq.top(); pq.pop();
			x = -x;
			if(nd[v] < x) continue;
			for(auto [u, w] : g[v]) {
				if(nd[u] > x + w && u != H) {
					nd[u] = x + w;
					pq.push({-nd[u], u});
				}
			} 
		}

		swap(nd, d);
		for(auto [u, w] : g[H]) {
			res = min(res, d[u] + w);
		}
	}

	if(res == 1e18) res = -1;
	return res;
}	

// int main() {
// 	cin.tie(0); ios_base::sync_with_stdio(0);

// 	cout << fixed << setprecision(1) << solve(4, 4, 30, 3, {0, 0, 1, 2}, {1, 2, 3, 3}, {5, 4, 2, 4}, {1, 0, 2, 1}) << '\n';
// 	cout << fixed << setprecision(1) << solve(3, 2, 30, 2, {1, 2}, {2, 0}, {12, 4}, {1, 2, 1}) << '\n';
// }

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