#include <bits/stdc++.h>
#include "cyberland.h"
#include <vector>
using namespace std;
using ll = long long;
const ll INF = 1e18;
vector<vector<ll> > adjList;
map<pair<ll, ll>, ll> weightMat;
vector<double> memo;
vector<bool> visited;
double DP(ll currentNode, ll N, ll H) {
// cout << currentNode << " " << numSpecialsLeft << endl;
if (currentNode == H) {
return 0.0;
}
if (visited[currentNode]) {
return memo[currentNode];
}
visited[currentNode] = true;
double minPossible = (double)INF;
for (ll v: adjList[currentNode]) { // currentNode -> v
minPossible = min(minPossible, DP(v, N, H) + (double)weightMat[{currentNode, v}]);
}
return memo[currentNode] = minPossible;
}
double solve(int N, int M, int K, int H, vector<int> x, vector<int> y, vector<int> c, vector<int> arr) {
adjList.clear();
weightMat.clear();
adjList.resize(N);
// weightMat.resize(N, vector<ll>(N, INF));
for (ll i = 0; i < M; i++) {
adjList[x[i]].push_back(y[i]);
adjList[y[i]].push_back(x[i]);
weightMat[{x[i], y[i]}] = c[i];
weightMat[{y[i], x[i]}] = c[i];
}
visited.clear();
memo.clear();
visited.resize(N, false);
memo.resize(N, INF);
double response = DP(0, N, H);
if (response >= INF) {
return -1.0;
} else {
return response;
}
}
