Submission #749157

#	Time	Username	Problem	Language	Result	Execution time	Memory
749157		gun_gan	Cyberland (APIO23_cyberland)	C++17	97 / 100	3074 ms	16644 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> 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});
				}
			} 
		}
	}

	vector<array<double, 2>> d(N, {1e18, 1e18});

	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][1] = 0;
				pq.push({0, i});
			}
		}

		while(!pq.empty()) {
			auto [x, v] = pq.top(); pq.pop();
			x = -x;
			if(d[v][1] < x) continue;
			for(auto [u, w] : g[v]) {
				if(d[u][1] > x + w && u != H) {
					d[u][1] = x + w;
					pq.push({-d[u][1], u});
				}
			} 
		}
	}


	double res = 1e18;

	for(auto [u, w] : g[H]) {
		res = min(res, d[u][1] + w);
	}

	for(int k = 1; k <= min(100, K); k++) {
		vector<array<double,2>> nd(N, {1e18, 1e18});

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

		while(!pq.empty()) {
			auto [x, p] = pq.top(); 
			auto [v, c] = p;
			pq.pop();

			x = -x;
			if(nd[v][c] < x) continue;
			for(auto [u, w] : g[v]) {
				if(nd[u][c | 1] > x + w && u != H) {
					nd[u][c | 1] = x + w;
					pq.push({-nd[u][c | 1], {u, c | 1}});
				}
			} 
		}

		swap(nd, d);
		for(auto [u, w] : g[H]) {
			res = min(res, min(d[u][0], d[u][1]) + 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';
// 	cout << fixed << setprecision(1) << solve(4, 3, 3, 3, {0, 1, 2}, {1, 2, 3}, {11, 1, 10}, {1, 1, 2, 1}) << '\n';
// }

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