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Cod sursa(job #869942)
#include <cmath>
#include <vector>
#include <cstdlib>
#include <fstream>
#include <iomanip>
#include <algorithm>
#define cin in
#define cout out
using namespace std;
typedef pair<int, int> pr;
typedef long long int lld;
const int NMAX = 100011;
pr X[NMAX], Y[NMAX], aux[NMAX];
inline lld _min(const lld& x, const lld& y) {return x <= y ? x : y;}
inline void _swap(pr& x, pr& y) {pr aux = x; x = y; y = aux;}
inline lld dSquare(const pr& x, const pr& y) {return 1LL * (x.first - y.first) * (x.first - y.first) + 1LL * (x.second - y.second) * (x.second - y.second);}
lld closestPoints(int left, int right)
{
lld minDSquare;
if(left >= right) return -1;
if(right - left <= 3)
{
minDSquare = dSquare(X[left], X[left + 1]);
for(int i = left; i < right; ++i)
{
for(int j = i + 1; j <= right; ++j)
{
minDSquare = _min(minDSquare, dSquare(X[i], X[j]));
if(Y[i].second > Y[j].second)
{
_swap(Y[i], Y[j]);
}
}
}
}
else {
int i, j, k, middle;
middle = (left + right) >> 1;
minDSquare = _min(closestPoints(left, middle), closestPoints(middle + 1, right));
for(i = k = left, j = middle + 1; i <= middle && j <= right; )
{
if(Y[i].second <= Y[j].second)
{
aux[k++] = Y[i++];
}
else {
aux[k++] = Y[j++];
}
}
for(; i <= middle; ++i, ++k) aux[k] = Y[i];
for(; j <= right; ++j, ++k) aux[k] = Y[j];
for(i = left; i <= right; ++i) Y[i] = aux[i];
for(k = 0, i = left; i <= right; ++i)
{
if(1LL * (X[middle].first - Y[i].first) * (X[middle].first - Y[i].first) <= minDSquare)
{
aux[k++] = Y[i];
}
}
k -= 1;
for(i = 0; i < k; ++i)
{
for(j = i + 1; j <= k && j - i < 8; ++j)
{
minDSquare = _min(minDSquare, dSquare(aux[i], aux[j]));
}
}
}
return minDSquare;
}
inline double closestPoints(int N)
{
sort(X, X + N);
return sqrt(1.0 * closestPoints(0, N - 1));
}
int main()
{
int N, i;
ifstream in("cmap.in");
ofstream out("cmap.out");
cin >> N;
for(i = 0; i < N; ++i)
{
cin >> X[i].first >> X[i].second;
Y[i] = X[i];
}
cout << fixed << setprecision(6) << closestPoints(N) << '\n';
return EXIT_SUCCESS;
}