topological.cpp

#include<iostream.h>
#include<stdio.h>
#include<conio.h>
void main()
{
  clrscr();
  int i,j,n,e[10][10],order[10]={0},ne=0;
  cout<<"\n Enter the value of n (i.e.), no of vertices:\t";
  cin>>n;
  cout<<"\n Enter the adjacency matrix:\n";
  for(i=0;i<n;i++)
  for(j=0;j<n;j++)
    scanf("%d",&e[i][j]);
  for(int l=0;l<n;l++)
  {
    for(i=0;i<n;i++)
    {
     for(j=0;j<n;j++)
      if(e[j][i] && i!=j) break;
     if(j==n && !order[i])
     {
      for(int k=0;k<n;k++)
       e[i][k]=0;
       order[i]=++ne;
      }
    }
   }
   if(ne<n)
    cout<<"\n The given graph is cyclic.";
   else
    {
     cout<<"\n Topological order:\n";
     for(i=0;i<n;i++)
      cout<<"\n Vertex: [ "<<(i+1)<<" ]\t order:\t"<<order[i];
     }
      getch();
}