Submission #977534

#	Time	Username	Problem	Language	Result	Execution time	Memory
977534		yusuf12360	Cyberland (APIO23_cyberland)	C++17	100 / 100	1188 ms	15264 KiB

cyberland

#include<bits/stdc++.h>
using namespace std;
const double INF=1e18;
double solve(int n, int m, int k, int h, vector<int> x, vector<int> y, vector<int> c, vector<int> a) {
	k=min(k, 100);
	vector<vector<pair<int, double>>> adj(n);
	for(int i=0; i<m; i++) {
		adj[x[i]].push_back({y[i], c[i]});
		adj[y[i]].push_back({x[i], c[i]});
	}
	vector<double> dist(n), temp(n); 
	for(auto &p : dist) p=INF;
	for(auto &p : temp) p=INF;
	priority_queue<pair<double, int>> pq;
	double ans=INF; temp[0]=0.;
	for(int j=0; j<=k; j++) {
		vector<double> temp(n); for(double &p : temp) p=INF;
		if(j) {
			for(int i=0; i<n; i++) {
				if(a[i]==1 || dist[i]==INF) continue;
				if(a[i]==0) temp[i]=0;
				pq.push({-dist[i]/2., i});
			}
		} else pq.push({0., 0});
		while(!pq.empty()) {
			auto [cur, u]=pq.top(); cur=-cur;
			pq.pop();
			if(u==h) continue;
			for(auto [v, w] : adj[u]) {
				if(temp[v]>cur+w) {
					if(a[v]==0) temp[v]=0.;
					else temp[v]=cur+w;
					pq.push({-temp[v], v});
				}
			}
		}
		ans=min(ans, temp[h]);
		if(j==0 && temp[h]==INF) break;
		swap(temp, dist);
	}
	return (ans<INF ? ans : -1.);
}
/*int main() {
	ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	int n, m, k, h; cin >> n >> m >> k >> h;
	vector<int> x(m), y(m), c(m), a(n);
	for(int &p : x) cin >> p;
	for(int &p : y) cin >> p;
	for(int &p : c) cin >> p;
	for(int &p : a) cin >> p;
	cout << solve(n, m, k, h, x, y, c, a) << '\n';
	return 0;
}*/

• 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: 3 / 3