| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 1228040 | pera | Cyberland (APIO23_cyberland) | C++20 | 0 ms | 0 KiB |
#include "cyberland.h"
#include <bits/stdc++.h>
#define LL __int128
#define int __int128
using namespace std;
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 , LL>>> g(N);
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]);
}
K = min(K , 30);
vector<vector<LL>> dist(N , vector<LL>(K + 1 , -1));
priority_queue<tuple<LL , int , int> , vector<tuple<LL , int , int>> , greater<tuple<LL , int , int>>> pq;
double ans = -1;
vector<bool> vis(N);
vis[0] = 0;
function<void(int)> dfs = [&](int u){
for(auto [v , w] : g[u]){
if(vis[v] == false){
vis[v] = true;
dfs(v);
}
}
};
dfs(0);
for(int i = 0;i < N;i ++){
if(vis[i] && (i == 0 || arr[i] == 0)){
dist[i][0] = 0;
pq.push(tuple<LL , int , int>{0 , i , 0});
}
}
while((int)pq.size()){
auto [D , u , x] = pq.top();
pq.pop();
if(dist[u][x] != D){
continue;
}
if(u == H){
long double S = D;
for(int i = 0;i < x;i ++){
S /= 2.0;
}
if(ans == -1){
ans = S;
}else{
ans = min(ans , (double)S);
}
continue;
}
for(auto [v , w] : g[u]){
LL nD = D + w * (1LL << x);
if(dist[v][x] == -1 || dist[v][x] > nD){
dist[v][x] = nD;
pq.push(tuple<LL , int , int>{dist[v][x] , v , x});
}
if(arr[v] == 2 && x < K){
++x;
if(dist[v][x] == -1 || dist[v][x] > nD){
dist[v][x] = nD;
pq.push(tuple<LL , int , int>{dist[v][x] , v , x});
}
}
}
}
return (double)ans;
}