Write a program in c to implement the depth first traversal?
#include <iostream.h>
#include <conio.h>
class graph
{
private:int n;
int **a;
int *reach;
int *pos;
public:graph(int k=10);
void create();
void dfs();
void dfs(int v,int label);
int begin(int v);
int nextvert(int v);
};
void graph::graph(int k)
{
n=k;
a=new int *[n+1];
reach=new int[n+1];
pos=new int [n+1];
for(int i=1;i<=n;i++)
pos[i]=0;
for(int j=1;j<=n;j++)
a[j]=new int[n+1];
}
void graph::create()
{
for(int i=1;i<=n;i++)
{
cout<<"Enter the "<<i<<"th row of matrix
a:
";
for(int j=1;j<=n;j++)
cin>>a[i][j];
}
for(int k=1;k<=n;k++)
reach[k]=0;
}
void graph::dfs()
{
int label=0;
for(int i=1;i<=n;i++)
if(!reach[i])
{
label++;
dfs(i,label);
}
cout<<"
The contents of the reach array is:
;
for(int j=1;j<=n;j++)
cout<<reach[j]<<" ";
}
void graph::dfs(int v,int label)
{
cout<<v<<" ";
reach[v]=label;
int u=begin(v);
while(u)
{
if(!reach[u])
dfs(u,label);
u=nextvert(v);
}
}
int graph::begin(int v)
{
if((v<1)&&(v>n))
cout<<"Bad input
";
else
for(int i=1;i<=n;i++)
if(a[v][i]==1)
{
pos[v]=i;
return i;
}
return 0;
}
int graph::nextvert(int v)
{
if((v<1)&&(v>n))
cout<<"Bad input
";
else
for(int i=pos[v]+1;i<=n;i++)
if(a[v][i]==1)
{
pos[v]=i;
return i;
}
return 0;
}
void main()
{
clrscr();
int x;
cout<<"Enter the no of vertices:
";
cin>>x;
graph g(x);
g.create();
cout<<"dfs is.....";
g.dfs();
getch();
}