kruskal.c

#include <stdio.h>
    #include <conio.h>
    #include <stdlib.h>

    int i, j, k, a, b, u, v, n, ne = 1;
    int min, mincost = 0, cost[9][9], parent[9];
    int find(int);
    int uni(int, int);
    void main() {
      printf("\n\tImplementation of Kruskal's Algorithm\n");
      printf("\nEnter the no. of vertices:");
      scanf("%d", & n);
      printf("\nEnter the cost adjacency matrix:\n");
      for (i = 1; i <= n; i++) {
        for (j = 1; j <= n; j++) {
          scanf("%d", & cost[i][j]);
          if (cost[i][j] == 0)
            cost[i][j] = 999;
        }
      }
      printf("The edges of Minimum Cost Spanning Tree are\n");
      while (ne < n) {
        for (i = 1, min = 999; i <= n; i++) {
          for (j = 1; j <= n; j++) {
            if (cost[i][j] < min) {
              min = cost[i][j];
              a = u = i;
              b = v = j;
            }
          }
        }
        u = find(u);
        v = find(v);
        if (uni(u, v)) {
          printf("%d edge (%d,%d) =%d\n", ne++, a, b, min);
          mincost += min;
        }
        cost[a][b] = cost[b][a] = 999;
      }
      printf("\n\tMinimum cost = %d\n", mincost);
      getch();
    }
    int find(int i) {
      while (parent[i])
        i = parent[i];
      return i;
    }
    int uni(int i, int j) {
      if (i != j) {
        parent[j] = i;
        return 1;
      }
      return 0;
    }