#include "cyberland.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair < long double , pair < int , int > > VAR;
const int MAXK = 31;
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) {
// cout << "starting " << endl;
bitset < 31 > vis[n];
fill(vis , vis + n , 0);
vector < pair < int , int > > graph[n];
for(int i = 0;i<m;i++){
graph[x[i]].push_back({y[i] , c[i]});
graph[y[i]].push_back({x[i] , c[i]});
}
priority_queue < VAR > pq;//dist , node , how much k used
pq.push({0,{0,0}});
function < void (int) > dfs = [&](int cur){
if(vis[cur] == 1 or cur == h)return;
vis[cur] = 1;
if(arr[cur] == 0){
pq.push({0,{cur,0}});
// cout << "pushed : " << cur << endl;
}
for(auto itr : graph[cur]){
dfs(itr.first);
}
};
// cout << "flag0 " << endl;
dfs(0);
fill(vis , vis + n , 0);
long double ans = 1;
// cout << "flag1 " << endl;
while(pq.size()){
VAR tmp = pq.top();
pq.pop();
if(vis[tmp.second.first][tmp.second.second])continue;
vis[tmp.second.first][tmp.second.second] = 1;
// cout << "pq : " << tmp.first.first << " / " << tmp.first.second << " , " << tmp.second.first << " " << tmp.second.second << endl;
if(tmp.second.first == h){
// cout << "flag1.1" << endl;
if(ans == 1 or ans < tmp.first){
ans = tmp.first;
}
// cout << "flag1.2" << endl;
}
else{
// cout << "flag2.1" << endl;
for(auto itr : graph[tmp.second.first]){
if(arr[tmp.second.first] == 2 and tmp.second.second < k){
pq.push({tmp.first / 2 - itr.second , {itr.first , tmp.second.second+1}});
}
pq.push({tmp.first - itr.second , {itr.first , tmp.second.second}});
}
// cout << "flag2.2" << endl;
}
}
// cout << "flag3 " << endl;
return -ans;
}
