primss.java

import java.util.*;

class primss {
    static int n, i, j, ne = 1;
    static int a, b, u, v;

    public static void main(String[] args) {
        int visited[] = new int[10]; //this will check whether that vertex is visited or not. 
        int cost[][] = new int[10][10]; //cost adjacency matrix
        int min, mincost = 0; 
        System.out.println("\n Enter the number of nodes:");
        Scanner in = new Scanner(System.in);
        n = in.nextInt();
        for (i = 1; i <= n; i++)
            visited[i] = 0; //initially no vertex is visited.
        System.out.println("\n Enter the adjacency matrix:\n");
        for (i = 1; i <= n; i++)
            for (j = 1; j <= n; j++) {
                cost[i][j] = in.nextInt();
                if (cost[i][j] == 0)
                    cost[i][j] = 999;
            }
        visited[1] = 1; //starting node is considered as visited
        while (ne < n) {
            min = 999;
            for (i = 1; i <= n; i++) {
                for (j = 1; j <= n; j++) {
                    if (cost[i][j] < min) {
                        if (visited[i] != 0) {
                            min = cost[i][j];
                            a = u = i; //this will contain the row of the minimum vertex
                            b = v = j; //this will contain the column of the minimum vertex
                        }
                    }
                }
            }
            if (visited[u] == 0 || visited[v] == 0) { 
                System.out.println(" Edge" + ne + ":" + u + "," + v + "cost:" + min); //this will print the edges
                ne++;
                mincost += min;
                visited[b] = 1;
            }
            cost[a][b] = cost[b][a] = 999; //visited edges needs to be changes to infinity
        }
        System.out.println(" Minimun cost=" + mincost); //prints the minimum cost.
    }
}