#include <bits/stdc++.h>
//#include "cyberland.h"
using namespace std;
#define ll long long
#define sz size()
#define ff first
#define ss second
#define pb push_back
#define pii pair <int, int>
const int N = 2e5 + 5;
vector <pii> v[N];
ll dis[N];
priority_queue <pair <ll, int>, vector<pair <ll, int>>, greater <pair <ll, int>>> q;
int n, m, k, h;
double solve(int N, int M, int K, int H, vector<int> x, vector<int> y, vector<int> c, vector<int> arr) {
n = N;m = M;k = K;h = H;
for (int i = 0; i < m; ++i) {
v[x[i]].pb ({y[i], c[i]});
v[y[i]].pb ({x[i], c[i]});
}
for (int i = 0; i < n; ++i) {
dis[i] = 1e16;
}
q.push ({0, h});
dis[h] = 0;
while (!q.empty()) {
int x = q.top().ss;
q.pop();
for (pii i : v[x]) {
if (dis[i.ff] > dis[x] + i.ss) {
dis[i.ff] = dis[x] + i.ss;
q.push({dis[i.ff], i.ff});
}
}
}
double jogap = 1e16;
jogap = min (jogap, (double)dis[0]);
// for (int i = 0; i < n; ++i) {
// if (arr[i] == 0) {
// jogap = min (jogap, (double)dis[i]);
// }
// }
if (jogap == (double)1e16) jogap = -1;
for (int i = 0; i < n; ++i) {
v[i].clear();
}
return jogap;
}
int main() {
freopen ("input.txt", "r", stdin);
int T;
assert(1 == scanf("%d", &T));
while (T--){
int N,M,K,H;
assert(4 == scanf("%d %d %d\n%d", &N, &M, &K, &H));
std::vector<int> x(M);
std::vector<int> y(M);
std::vector<int> c(M);
std::vector<int> arr(N);
for (int i=0;i<N;i++)
assert(1 == scanf("%d", &arr[i]));
for (int i=0;i<M;i++)
assert(3 == scanf("%d %d %d", &x[i], &y[i], &c[i]));
printf("%.12lf\n", solve(N, M, K, H, x, y, c, arr));
}
}
/*
1
3 2 30
2
1 2 1
1 2 12
2 0 4
answer : 4.00000000000
1
4 4 30
3
1 0 2 1
0 1 5
0 2 4
1 3 2
2 3 4
answer : 2.00000000000
*/
Compilation message
cyberland.cpp: In function 'int main()':
cyberland.cpp:56:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
56 | freopen ("input.txt", "r", stdin);
| ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
/usr/bin/ld: /tmp/ccKGJmxl.o: in function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/ccMsvWQm.o:cyberland.cpp:(.text.startup+0x0): first defined here
collect2: error: ld returned 1 exit status
