Submission #982090

#	Time	Username	Problem	Language	Result	Execution time	Memory
982090		vjudge1	Cyberland (APIO23_cyberland)	C++17	100 / 100	1185 ms	15492 KiB

cyberland

// hola soy Dember :D
// 31/03/2024

#include <bits/stdc++.h>
#define dd double

using namespace std;

const dd inf=1e18;

dd 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, dd>>> v(n);
	for(int i=0; i<m; i++){
		v[x[i]].push_back({y[i], c[i]});
		v[y[i]].push_back({x[i], c[i]});
	}
	
	vector<double> dp(n), tt(n); 
	for(auto &p:dp) p=inf;
	for(auto &p:tt) p=inf;
	
	priority_queue<pair<dd, int>> q;
	tt[0]=0.;
    dd ans=1e18;
    
	for(int j=0; j<=k; j++){
		vector<double> tt(n); for(double &p:tt) p=inf;
		if(j){
			for(int i=0; i<n; i++){
				if(a[i]==1 || dp[i]==inf) continue;
				if(a[i]==0)tt[i]=0;
				q.push({-dp[i]/2., i});
			}
		} else q.push({0., 0});
		
		while(!q.empty()) {
			auto [cur, u]=q.top(); cur=-cur;
			q.pop();
			if(u==h) continue;
			for(auto [v, w]:v[u]) {
				if(tt[v]>cur+w) {
					if(a[v]==0) tt[v]=0.;
					else tt[v]=cur+w;
					q.push({-tt[v], v});
				}
			}
		}
		ans=min(ans, tt[h]);
		if(j==0 && tt[h]==inf) break;
		swap(tt, dp);
	}
	return ((ans<inf)? ans: -1.);
}

• 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