Kruskal

package mst.kruskal;

import java.util.*;

public class Kruskal {
    /**
     * Minimum spanning tree - Krukal's Algorithm
     * @author Kaidul
     * @category Graph
     */
    static final int MAX = 100;
    int u, v, cost;
    static Kruskal[] k = new Kruskal[MAX];
//  Vector <Integer> parentSet = new Vector <Integer> ();
    static int[] parentSet = new int[100];

    void initSet(int _size){
//      parentSet.setSize(_size);
        for (int i = 0; i <= _size; i++) {
            parentSet[i] = i;
        }
    }

    static int findSet(int var){
        if (parentSet[var] == var) {
            return var;
        }
        else return parentSet[var] = findSet(parentSet[var]);
    }

    static void unionSet(int a, int b){
        if (parentSet[a] == a) {
            parentSet[a] = findSet(b);
            return;
        } else if (parentSet[b] == b)  {
            parentSet[b] = findSet(a);
        } else{
            int m = findSet(a);
            int n = findSet(b);
            parentSet[m] = n;
        }
    }

    static Vector <Integer> vec = new Vector <Integer> ();

    static void mst(int edge, int vertex){
        int sum = 0;
        for (int i = 0; i < edge; i++) {
            if (findSet(k[i].u) != findSet(k[i].v)) {
                vec.add(k[i].cost);
                sum += k[i].cost;
                unionSet(k[i].u, k[i].v);
            }
        }
        System.out.println("The minimum spanning tree" + sum);
    }

    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        int vertex_no = input.nextInt();
        int edge_no = input.nextInt();
        for (int i = 0; i < edge_no; i++) {
            k[i].u = input.nextInt();
            k[i].v = input.nextInt();
            k[i].cost = input.nextInt();
        }
        mst(edge_no, vertex_no);

//        Scanner input = new Scanner(System.in);
//        while(input.hasNext())
//            System.out.println(input.nextBigInteger()
//               .subtract(input.nextBigInteger()).abs());
    }

}