Editing 2016 Dec Gold Problem 1 Moocast (section)

=== Java ===
<pre>
import java.io.*;
import java.util.*;

public class MooCast {
    static class Edge implements Comparable<Edge> {
        int i, j, w;

        public Edge(int i, int j, int w) {
            this.i = i;
            this.j = j;
            this.w = w;
        }

        @Override
        public int compareTo(Edge other) {
            return this.w - other.w;
        }
    }

    static int[] parent;

    public static int find(int curr) {
        return parent[curr] == curr ? curr : (parent[curr] = find(parent[curr]));
    }

    public static void merge(int x, int y) {
        parent[find(x)] = find(y);
    }

    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new FileReader("moocast.in"));
        PrintWriter pw = new PrintWriter(new BufferedWriter(new FileWriter("moocast.out")));
        int n = Integer.parseInt(br.readLine());
        int[] x = new int[n];
        int[] y = new int[n];
        for (int i = 0; i < n; i++) {
            StringTokenizer st = new StringTokenizer(br.readLine());
            x[i] = Integer.parseInt(st.nextToken());
            y[i] = Integer.parseInt(st.nextToken());
        }
        parent = new int[n];
        ArrayList<Edge> edges = new ArrayList<>();
        for (int i = 0; i < n; i++) {
            parent[i] = i;
            for (int j = 0; j < i; j++) {
                int distance = (x[i] - x[j]) * (x[i] - x[j]) + (y[i] - y[j]) * (y[i] - y[j]);
                edges.add(new Edge(i, j, distance));
            }
        }
        Collections.sort(edges);
        int lastWeight = 0;
        int numComponents = n;
        for (Edge curr : edges) {
            if (find(curr.i) != find(curr.j)) {
                merge(curr.i, curr.j);
                lastWeight = curr.w;
                if (--numComponents == 1) {
                    break;
                }
            }
        }
        pw.println(lastWeight);
        pw.close();
    }
}

</pre>