#include <bits/stdc++.h>
using std::vector;
using std::array;
using std::pair;
using std::tuple;
using i64 = std::int64_t;
struct SimpleQueue {
int idx;
vector<int> data;
SimpleQueue(const int n) : idx(0) { data.reserve(n); }
void clear() {
idx = 0;
data.clear();
}
void push(const int x) {
data.push_back(x);
}
int pop() {
return data[idx++];
}
bool empty() const {
return idx == (int)data.size();
}
};
int main() {
std::ios_base::sync_with_stdio(false);
std::cin.tie(nullptr);
int N;
std::cin >> N;
vector<double> X(N), Y(N);
for (int i = 0; i < N; ++i) {
std::cin >> X[i] >> Y[i];
}
vector dis(N, vector<double>(N));
for (int i = 0; i < N; ++i) {
for (int j = 0; j < N; ++j) {
dis[i][j] = std::hypot(X[i] - X[j], Y[i]- Y[j]);
}
}
vector<char> reach(N);
SimpleQueue que(N);
const auto check = [&](const double thres) {
std::fill(reach.begin(), reach.end(), false);
que.clear();
const auto push = [&](const int u) {
if (!reach[u]) {
reach[u] = true;
que.push(u);
}
};
push(0);
while (!que.empty()) {
const int u = que.pop();
for (int v = 0; v < N; ++v) {
if (dis[u][v] <= 2.0 * thres) {
push(v);
}
}
}
return std::count(reach.begin(), reach.end(), true) == N;
};
double ok = 2.0 * 1e9, ng = 0.0;
for (int step = 0; step < 55; ++step) {
const double md = (ok + ng) / 2.0;
(check(md) ? ok : ng) = md;
}
std::cout << std::fixed << std::setprecision(20);
std::cout << ok << '\n';
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
204 KB |
Output is correct |
2 |
Correct |
1 ms |
204 KB |
Output is correct |
3 |
Correct |
1 ms |
332 KB |
Output is correct |
4 |
Correct |
1 ms |
384 KB |
Output is correct |
5 |
Correct |
3 ms |
332 KB |
Output is correct |
6 |
Correct |
28 ms |
2252 KB |
Output is correct |
7 |
Correct |
30 ms |
2252 KB |
Output is correct |
8 |
Correct |
57 ms |
4684 KB |
Output is correct |
9 |
Correct |
105 ms |
8160 KB |
Output is correct |
10 |
Correct |
113 ms |
8184 KB |
Output is correct |