#include "bits/stdc++.h"
#include "cyberland.h"
using namespace std;
#include <vector>
void dfs(int x, int p, vector<pair<int, double>> adj[], double dist[], vector<int> &arr, int H, bool vis[]) {
vis[x] = 1;
if(arr[x] == 0) dist[x] = 0;
if(x == H) return;
for(auto [y, w] : adj[x]) {
if(y == p || vis[y]) continue;
dfs(y, x, adj, dist, arr, H, vis);
}
}
double solve(int N, int M, int K, int H, vector<int> x, vector<int> y, vector<int> c, vector<int> arr) {
vector<pair<int, double>> adj[N];
for(int i = 0; i < M; ++i) {
adj[x[i]].emplace_back(y[i], c[i]);
adj[y[i]].emplace_back(x[i], c[i]);
}
double dist[N];
for(int i = 0; i < N; ++i) dist[i] = -1;
dist[0] = 0;
bool vis[N] = {};
dfs(0, -1, adj, dist, arr, H, vis);
queue<int> q;
for(int i = 0; i < N; ++i) if(dist[i] == 0) q.push(i);
while(!q.empty()) {
int a = q.front();
q.pop();
for(auto [b, w] : adj[a]) {
if(dist[b] == -1 || dist[b] > dist[a] + w) {
dist[b] = dist[a] + w;
q.push(b);
}
}
}
return dist[H];
/* vector<pair<int, double>> adj[N]; */
/* for(int i = 0; i < M; ++i) { */
/* adj[x[i]].emplace_back(y[i], c[i]); */
/* adj[y[i]].emplace_back(x[i], c[i]); */
/* } */
/* double dist[N]; */
/* for(int i = 0; i < N; ++i) dist[i] = -1; */
// there's a pq declared earlier as well
/* priority_queue<pair<double, int>> pq; */
/* for(int i = 1; i < N; ++i) { */
/* if(arr[i] == 0 || i == 0) { */
/* dist[i] = 0; */
/* pq.emplace(-dist[i], i); */
/* } */
/* } */
/* while(!pq.empty()) { */
/* int a = pq.top().second; */
/* double d = -pq.top().first; */
/* pq.pop(); */
/* if(dist[a] < d || a == H) { */
/* continue; */
/* } */
/* for(auto [b, w] : adj[a]) { */
/* if(dist[b] == -1 || d + w < dist[b]) { */
/* dist[b] = d + w; */
/* pq.emplace(-dist[b], b); */
/* } */
/* } */
/* } */
/* return dist[
*/
}
