Nearest point pair (Java implementation)

Recent point to question:

In n points on a two-dimensional plane, the distance of the nearest pair of points is fast.

Java implementations:

Package P2;import static Java.lang.math.*;import Java.util.arraylist;import Java.util.arrays;import Java.util.collections;import Java.util.comparator;import Java.util.scanner;public class CloestPair {//coordinate point static Class Point {public ' point () {}public point (Double x, double y) {this.x = X;this.y = y;} Double x;double Y;} public static void Main (string[] args) {Scanner Scanner = new Scanner (system.in), while (true) {int n = scanner.nextint ();P Oint[] ps = new Point[n];for (int i = 0; i < n; i++) {Double x = scanner.nextdouble ();d ouble y = scanner.nextdouble ();p S[i] = new Point (x, y);}  Sort by x-coordinate ascending arrays.sort (PS, New comparator<point> () {@Overridepublic int compare (point O1, point O2) {if (o1.x < o2.x) return-1;if (o1.x > o2.x) return 1;if (O1.y < O2.Y) return-1;if (O1.y > O2.y) return 1;return 0;}}); Double Mindis = mindistance (PS, 0, n-1); System.out.println (Mindis);}} /** * Minimum distance between point pairs * * @param PS * @param l * @param r * @return */public static double mindistance (point[]PS, int l, int r) {/** * The same point, there is no point pair, distance cannot take 0, return maximum value */if (L = = r) {return double.max_value;} if (l + 1 = = r) {return distance (Ps[l], ps[r]);} int center = l + (r-l)/2;double dis1 = Mindistance (PS, L, center);d ouble dis2 = mindistance (PS, center + 1, R);d ouble Mindis = min (dis1, DIS2);  arraylist<point> nearpoints = new arraylist<> ();//Select a point in the middle line less than Mindis for (points p:ps) {if (ABS (ps[center].x- p.x) <= Mindis) {nearpoints.add (P);}} Sort by y-axis ascending collections.sort (nearpoints, New comparator<point> () {@Overridepublic int compare (point O1, point O2) { if (O1.y < O2.Y) return-1;if (O1.y > O2.y) return 1;if (o1.x < o2.x) return-1;if (o1.x > o2.x) return 1;return 0 ;}}); for (int i = 0; i < nearpoints.size (), i++) {for (int j = i + 1, J < Nearpoints.size (); j + +) {if (Nearpoints.get (j). Y-nearpoints.get (i). Y > Mindis) {break;//element y+1 away from element I, no need to continue comparing}double D = Distance (Nearpoints.get (j), Nearpoints.get (i)); if (d < mindis) {Mindis = D;}}} return Mindis;} Public STATic double distance (point P1, point p2) {if (P1 = = p2) return 0;return sqrt (POW (p1.x-p2.x, 2) + POW (P1.Y-P2.Y, 2));}} 

Nearest point pair (Java implementation)