#include "cyberland.h"
#include <bits/stdc++.h>
#define F first
#define S second
#define elif else if
#define pb push_back
#define int long long
using namespace std;
const int N=1e5+5;
int n,m,k,a[N],h;
double dis[N][95];
vector<pair<int,int>> adj[N];
bool vis[N][95];
vector<int> v;
void dfs(int x){
if (!a[x] && x) v.pb(x);
vis[x][94]=1;
for (auto u:adj[x]){
if (vis[u.F][94]) continue;
dfs(u.F);
}return;
}
void dijkstra(){
priority_queue<pair<double,pair<int,int>>> pq;
for (auto u:v) pq.push({0,{u,0}}),dis[u][0]=0;
if (pq.empty()) pq.push({0,{0,0}}),dis[0][0]=0;
while (!pq.empty()){
int i=pq.top().S.F,j=pq.top().S.S;
//cout<<i<<' '<<j<<endl;
pq.pop();
if (vis[i][j] || i==h) continue;
vis[i][j]=1;
for (auto u:adj[i]){
if (dis[i][j]+u.S<dis[u.F][j] || dis[u.F][j]<0){
dis[u.F][j]=dis[i][j]+u.S;
pq.push({-dis[u.F][j],{u.F,j}});
}
if (a[u.F]==2){
if ((dis[i][j]+u.S)/2.0<dis[u.F][j+1] || dis[u.F][j+1]<0){
dis[u.F][j+1]=(dis[i][j]+u.S)/2.0;
pq.push({-dis[u.F][j+1],{u.F,j+1}});
}
}
}
}return;
}
double solve(int32_t N, int32_t M, int32_t K, int32_t H, std::vector<int32_t> x, std::vector<int32_t> y, std::vector<int32_t> c, std::vector<int32_t> arr) {
n=N;m=M;k=min(K,90);v.clear();h=H;
for (int i=0;i<n;i++){
adj[i].clear();
for (int j=0;j<=k;j++) vis[i][j]=0,dis[i][j]=-1;
vis[i][94]=0;
}
for (int i=0;i<m;i++){
adj[x[i]].pb({y[i],c[i]});
adj[y[i]].pb({x[i],c[i]});
}
for (int i=0;i<n;i++) a[i]=arr[i];
dfs(0);
dijkstra();
double ans=-1;
for (int i=0;i<=k;i++) if (dis[H][i]>=0 && (ans==-1 || dis[H][i]<ans)) ans=dis[H][i];
return ans;
}
