DISTANCE VECTOR ROUTING PROGRAM IN C++

// SIMULATE DISTANCE VECTOR ROUTING
// ALWAYS DRY RUN FOR BETTER UNDERSTANDING

# include <iostream.h>
# include <conio.h>
# include <stdio.h>
# include <string.h>

class router
{
 private:
  char name[20];
  int dist[10];

 public:
  void get_r_table (int , int);
  friend void find_table (router *);
};

void find_table (router *);

int total_r;
int adj;
char names[10][20];
char N[20];

void router :: get_r_table (int no , int flag)
{
 if ( flag == 1 )
 {
  cout << "Enter the name of the adjacent router " << no << " : ";
  gets (name);
 }
 else
  strcpy (name , N);

 cout << "Enter the distances of each router from this router :\n";
 cout << "\tROUTER\tDISTANCE\n";
 cout << "\t------\t--------\n";

 for (int i = 0 ; i < total_r ; i++)
 {
  cout << "\t" << names[i] << "\t";
  if ( strcmp ( names[i] , name ) == 0 )
  {
   dist[i] = 0;
   cout << dist[i] << "\n";
  }
  else
   cin >> dist[i];
 }
}

void find_table(router *r)
{
 cout << "Routing table for router " << N << " :-\n";
 cout << "\tRouter\tDistance\n";
 cout << "\t------\t--------\n";

 for ( int i = 0 ; i < total_r ; i++ )
 {
  int temp;
  if ( strcmp (N , names[i] ) == 0 )
   temp = 0;
  else
  {
   temp = r[0].dist[i];
   for ( int j = 1 ; j < adj + 1 ; j++ )
    if ( r[j].dist[i] < temp && r[j].dist[i] != 0 )
     temp = r[j].dist[i] + r[0].dist[j];
  }
  r[0].dist[i] = temp;
 // r[0] contains data of the router whose routing table is to be found out
 }

 for ( i = 0 ; i < total_r ; i++ )
 {
  cout << "\t" << names[i] << "\t";
  cout << r[0].dist[i] << "\n";
 }
}

void main()
{
 router r[10];

 clrscr();

 cout << "Enter the total no of routers in the subnet [MAX 10] :- ";
 cin >> total_r;
 cout << "Enter the names of all the routers :-\n";
 for (int i = 0 ; i < total_r ; i++)
 {
  cout << "\t" << i + 1 << " . ";
  gets (names[i]);
 }
 cout << "Enter the router whose routing table is to be found out : ";
 gets (N);

 cout << "Enter the no of routers adjacent to this router : ";
 cin >> adj;

 int flag = 0;
 for ( i = 0 ; i < adj + 1; i++ )
 {
  r[i].get_r_table (i , flag);
  flag = 1;
 }

 find_table (r);
 getch();
}


/*                 OUTPUT


Enter the total no of routers in the subnet [MAX 10] :- 6
Enter the names of all the routers :-
        1 . A
        2 . B
        3 . C
        4 . D
        5 . E
        6 . F
Enter the router whose routing table is to be found out : C
Enter the no of routers adjacent to this router : 3
Enter the distances of each router from this router :
        ROUTER  DISTANCE
        ------  --------
        A       11
        B       6
        C       0
        D       3
        E       5
        F       6
Enter the name of the adjacent router 1 : B
Enter the distances of each router from this router :
        ROUTER  DISTANCE
        ------  --------
        A       5
        B       0
        C       8
        D       12
        E       6
        F       2
Enter the name of the adjacent router 2 : D
Enter the distances of each router from this router :
        ROUTER  DISTANCE
        ------  --------
        A       16
        B       12
        C       6
        D       0
        E       9
        F       10
Enter the name of the adjacent router 3 : E
Enter the distances of each router from this router :

        ROUTER  DISTANCE
        ------  --------
        A       7
        B       6
        C       3
        D       9
        E       0
        F       1
Routing table for router C :-
        Router  Distance
        ------  --------
        A       10
        B       6
        C       0
        D       3
        E       5
        F       4

*/