#include "cyberland.h"
#include <bits/stdc++.h>
#define int long long
#define emb emplace_back
#define pii pair <int, int>
#define tiii tuple <int, int, int>
#define tdii tuple <double, int, int>
#define all(a) a.begin(), a.end()
using namespace std;
const int N = 1e5 + 5;
const double inf = 1e18;
double solve(int32_t n, int32_t m, int32_t k, int32_t h, vector<int32_t> x, vector<int32_t> y, vector<int32_t> c, vector<int32_t> arr) {
vector <pair <double, int>> adj[n + 1];
for (int i = 0; i < m; i++) {
adj[x[i]].emb(c[i], y[i]);
adj[y[i]].emb(c[i], x[i]);
}
double dis[n + 1][k + 1]; for (int i = 1; i < n; i++) for (int j = 0; j <= k; j++) dis[i][j] = inf, dis[0][j] = 0;
priority_queue <tdii, vector <tdii>, greater <tdii>> q; q.emplace(0, 0, 0);
while (!q.empty()) {
auto [w, u, cnt] = q.top(); q.pop();
if (w > dis[u][cnt]) continue;
if (u == h) continue;
for (auto [ww, v] : adj[u]) {
double nw = w + ww;
if (arr[v] == 0) {
if (dis[v][cnt] > 0) {
dis[v][cnt] = 0;
q.emplace(dis[v][cnt], v, cnt);
}
}
if (arr[v] == 1) {
if (nw < dis[v][cnt]) {
dis[v][cnt] = nw;
q.emplace(dis[v][cnt], v, cnt);
}
}
if (arr[v] == 2) {
if (cnt < k) {
double div = nw/2;
if (div < dis[v][cnt + 1]) {
dis[v][cnt + 1] = div;
q.emplace(dis[v][cnt + 1], v, cnt + 1);
}
}
if (nw < dis[v][cnt]) {
dis[v][cnt] = nw;
q.emplace(dis[v][cnt], v, cnt);
}
}
}
}
double ans = inf;
for (int i = 0; i <= k; i++) ans = min(ans, dis[h][i]);
if (ans == inf) return -1;
else return ans;
}
