#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 <ll, ll>
const int N = 2e5 + 5;
vector <pii> v[N];
ll dis[N];
priority_queue <pair <ll, ll>, vector<pair <ll, ll>>, greater <pair <ll, ll>>> q;
ll n, m, k, h, vis[N];
vector <ll> a, tt;
double jogap = 1e16;
void dfs (ll x) {
vis[x] = 1;
if (a[x] == 0) {
tt.pb (x);
}
for (pii i : v[x]) {
if (vis[i.ff]) continue;
dfs(i.ff);
}
}
void dfs1(int x, int par, double val) {
if (x == h) {
jogap = min (jogap, val);
return;
}
for (pii i : v[x]) {
if (i.ff == par or i.ff == 0) {
continue;
}
double new_val = val + i.ss;
if (!a[i.ff]) new_val = 0;
else if (a[i.ff] == 2 and k != 0) new_val /= 2.0;
dfs1 (i.ff, x, new_val);
}
}
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;
a.resize(n);
for (int i = 0; i < n; ++i) {
a[i] = arr[i];
}
for (int i = 0; i < m; ++i) {
v[x[i]].pb ({y[i], c[i]});
v[y[i]].pb ({x[i], c[i]});
}
if (n <= 3) {
dfs1(0, -1, 0);
if (jogap == 1e16) jogap = -1;
for (int i = 0; i < n; ++i) {
v[i].clear();
}
return jogap;
}
for (ll i = 0; i < n; ++i) {
dis[i] = 1e16;
}
q.push ({0, h});
dis[h] = 0;
while (!q.empty()) {
ll 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});
}
}
}
jogap = 1e16;
jogap = min (jogap, (double)dis[0]);
vis[h] = 1;
dfs (0);
for (ll i : tt) {
jogap = min (jogap, (double)dis[i]);
}
if (jogap == (double)1e16) jogap = -1;
for (ll i = 0; i < n; ++i) {
v[i].clear();
vis[i] = 0;
}
tt.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
*/
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
10 ms |
8024 KB |
Wrong Answer. |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
14 ms |
8284 KB |
Correct. |
2 |
Correct |
17 ms |
9308 KB |
Correct. |
3 |
Correct |
19 ms |
9052 KB |
Correct. |
4 |
Correct |
19 ms |
9308 KB |
Correct. |
5 |
Correct |
18 ms |
9272 KB |
Correct. |
6 |
Correct |
16 ms |
10076 KB |
Correct. |
7 |
Correct |
21 ms |
10332 KB |
Correct. |
8 |
Correct |
12 ms |
10332 KB |
Correct. |
9 |
Incorrect |
20 ms |
9052 KB |
Wrong Answer. |
10 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
17 ms |
8280 KB |
Correct. |
2 |
Incorrect |
18 ms |
9048 KB |
Wrong Answer. |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
22 ms |
13916 KB |
Wrong Answer. |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
19 ms |
8404 KB |
Wrong Answer. |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
17 ms |
8280 KB |
Correct. |
2 |
Correct |
16 ms |
9268 KB |
Correct. |
3 |
Correct |
31 ms |
17240 KB |
Correct. |
4 |
Correct |
12 ms |
9816 KB |
Correct. |
5 |
Incorrect |
16 ms |
9004 KB |
Wrong Answer. |
6 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
15 ms |
8336 KB |
Wrong Answer. |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
16 ms |
8280 KB |
Wrong Answer. |
2 |
Halted |
0 ms |
0 KB |
- |