212 lines
4.0 KiB
C++

/* Problem URL: https://codeforces.com/gym/104020/problem/L?mobile=false */
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
template <class T, class comp = less<>>
using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
#define V vector
#define rmin(a, b) a = min(a, b)
#define rmax(a, b) a = max(a, b)
#define rep(i, lim) for (int i = 0; i < (lim); i++)
#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
#define repv(i, v) for (auto &i : (v))
#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
#define sortv(v) sort(v.begin(), v.end())
#define all(v) (v).begin(), (v).end()
using vi = vector<int>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;
using vvvvi = vector<vvvi>;
using ll = long long;
using vl = vector<ll>;
using vvl = vector<vl>;
using vvvl = vector<vvl>;
using vvvvl = vector<vvvl>;
template<class v>
auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
os << vec[0];
for (size_t i = 1; i < vec.size(); i++) {
os << ' ' << vec[i];
}
os << '\n';
return os;
}
template<class v>
auto operator>>(istream &is, vector<v> &vec)->istream& {
for (auto &i : vec) {
is >> i;
}
return is;
}
template<class v>
auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
for (auto &i : vec) {
os << i[0];
for (size_t j = 1; j < i.size(); j++) {
os << ' ' << i[j];
}
os << '\n';
}
return os;
}
template<class v>
auto operator>>(istream &is, vector<vector<v>> &vec)->istream& {
for (auto &i : vec) {
for (auto &j : i) {
is >> j;
}
}
return is;
}
const int oo = INT32_MAX >> 1;
const ll OO = INT64_MAX >> 1;
void pre()
{
}
#define TEST 0
struct point {
ll x;
ll y;
ll z;
friend istream &operator>>(istream &is, point &a) {
is >> a.x >> a.y >> a.z;
return is;
}
bool operator<(point b) const {
if (x == b.x) {
if (y == b.y) {
return z < b.z;
}
return y < b.y;
}
return x < b.x;
}
};
ll sqr(ll x)
{
return x * x;
}
long double dis(point a, point b)
{
ll x = a.x - b.x;
ll y = a.y - b.y;
ll z = a.z - b.z;
return sqrtl(sqr(x) + sqr(y) + sqr(z));
}
void solve()
{
int n;
cin >> n;
V<point> p(n);
cin >> p;
sortv(p);
long double ans = 1e16;
struct compy {
bool operator()(point a, point b) const {
if (a.y == b.y) {
if (a.z == b.z) {
return a.x > b.x;
}
return a.z > b.z;
}
return a.y > b.y;
}
};
struct compz {
bool operator()(point a, point b) const {
if (a.z == b.z) {
if (a.x == b.x) {
return a.y > b.y;
}
return a.x > b.x;
}
return a.z > b.z;
}
};
set<point, compy> sy;
set<point, compz> sz;
sy.emplace(p[0]);
sz.emplace(p[0]);
int cur = 0;
nrep(i, 1, n) {
while (p[cur].x < p[i].x - ans) {
sy.erase(p[cur]);
sz.erase(p[cur]);
cur++;
}
auto itr = sy.lower_bound(point(1e9, p[i].y + ans, 1e9));
while (itr != sy.end() && abs(p[i].y - itr->y) <= ans) {
rmin(ans, dis(p[i], *itr));
itr++;
}
itr = sz.lower_bound(point(1e9, 1e9, p[i].z + ans));
while (itr != sz.end() && abs(p[i].z - itr->z) <= ans) {
rmin(ans, dis(p[i], *itr));
itr++;
}
sy.emplace(p[i]);
sz.emplace(p[i]);
}
cout << fixed << setprecision(7) << ans << '\n';
}
int main()
{
ios::sync_with_stdio(false);
cin.tie(nullptr);
pre();
int t;
(TEST && cin >> t) || (t = 1);
while (t--) {
solve();
}
}