#include<bits/stdc++.h>
#define pb push_back
using namespace std;
double solve (int N, int M, int K, int H, vector<int> x, vector<int> y, vector<int> c, vector<int> arr) {
vector<vector<pair<int, double>>> edge(N);
for (int i = 0; i < M; i ++) {
edge[x[i]].pb({y[i], c[i]});
edge[y[i]].pb({x[i], c[i]});
}
vector<vector<bool>> visited(N, vector<bool>(K+1, false));
queue<int> q;
q.push(0);
while (!q.empty()) {
int v = q.front(); q.pop();
if (v == H) continue;
for (auto [u, w] : edge[v]) {
if (visited[u][0]) continue;
visited[u][0] = true;
q.push(u);
}
}
priority_queue<pair<double, pair<int, int>>> pq;
vector<vector<double>> dist(N, vector<double>(K+1, 1e19));
// dp[i][t] = min cost to reach to node i with t times of power 2 ability used
dist[0][0] = 0;
pq.push({0, {0, 0}}); // {-w, {v, k}}
for (int i = 0; i < N; i ++) {
if (arr[i] == 0 && visited[i][0]) {
pq.push({0, {i, 0}});
dist[i][0] = 0;
}
}
visited.clear();
visited.resize(N, vector<bool>(K+1, false));
while (!pq.empty()) {
int v = pq.top().second.first, k = pq.top().second.second; pq.pop();
if (visited[v][k]) continue;
visited[v][k] = true;
for (auto [u, w] : edge[v]) {
if (dist[v][k] + w < dist[u][k]) {
dist[u][k] = dist[v][k] + w;
pq.push({ (dist[u][k]*(-1)) , {u, k}});
}
if (arr[u] == 2 && k+1 <= K) {
if ( (dist[v][k] + w)/2 < dist[u][k+1]) {
dist[u][k+1] = (dist[v][k] + w)/2;
pq.push({ (dist[u][k+1]*(-1)), {u, k+1}});
}
}
}
}
double mn = 1e19;
for (int i = 0; i <= K; i ++) {
mn = min(mn, dist[H][i]);
}
if (mn == 1e19) {return (double)-1;}
return (double)mn;
}
