DISTANCE VECTOR ROUTING ALGORITHM

DISTANCE VECTOR ROUTING ALGORITHM

#include<stdio.h>

struct node

{

                                      unsigned dist[20];

                                      unsigned from[20];

}

rt[10];

int main()

{

                                      int dmat[20][20];

                                      int n,i,j,k,count=0;

                                      printf("\nEnter the number of nodes : ");

                                      scanf("%d",&n);

                                      printf("\nEnter the cost matrix :\n");

                                      for(i=0;i<n;i++)

                                      for(j=0;j<n;j++)

                                      {       

                                                scanf("%d",&dmat[i][j]);

                                                dmat[i][i]=0;

                                                rt[i].dist[j]=dmat[i][j];

                                                rt[i].from[j]=j;

                                      }

                                      do

                                      {       

                                                count=0;

                                                for(i=0;i<n;i++)

                                                for(j=0;j<n;j++)

                                                for(k=0;k<n;k++)

                                                if(rt[i].dist[j]>dmat[i][k]+rt[k].dist[j])

                                                {

                                                          rt[i].dist[j]=rt[i].dist[k]+rt[k].dist[j];

                                                          rt[i].from[j]=k;

                                                          count++;

                                                }

                                      }

while(count!=0);

                                      for(i=0;i<n;i++)

                                      {

                                                printf("\n\nState value for router %d is \n",i+1);

                                                for(j=0;j<n;j++)

                                                {

                                           printf("\t\nnode %d via %d Distance%d",j+1,             rt[i].from[j]+1,rt[i].dist[j]);

}

                                      }       

                                      printf("\n\n");

}

Output:

Enter the number of nodes : 4

Enter the cost matrix :

0 3 5 99

3 0 99 1

5 4 0 2

99 1 2 0

  State value for router 1 is

node 1 via 1 Distance0

node 2 via 2 Distance3

node 3 via 3 Distance5

node 4 via 2 Distance4

State value for router 2 is

node 1 via 1 Distance3

node 2 via 2 Distance0

node 3 via 4 Distance3

node 4 via 4 Distance1

State value for router 3 is

node 1 via 1 Distance5

node 2 via 4 Distance3

node 3 via 3 Distance0

node 4 via 4 Distance2

State value for router 4 is

node 1 via 2 Distance4

node 2 via 2 Distance1

node 3 via 3 Distance2

node 4 via 4 Distance0