7. Implement distance vector routing algorithm for obtaining routing tables at each node.

#include<stdio.h>
struct node
{
 unsigned dist[20];
 unsigned from[20];
}
rt[20];
int main()
{
 int dmat[20][20];int n,i,j,k,count=0;
 printf("\n Enter number of nodes:");
 scanf("%d",&n);
 printf("Enter 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 State value for router %d is \n",i+1);
 for(j=0;j<n;j++)
 {
 printf("\n node %d via %d Distance %d",j+1,rt[i].from[j]+1,rt[i].dist[j]);
 }
 } 
}