Insertion into beginning and at last node in Linklist in C/C++

#include<bits/stdc++.h>
#include<conio.h>
using namespace std;
struct node
{
int info;
node *link;
};
void insertFirst(node** start,int num)
{

struct node *temp=new node;
temp->info=num;
temp->link=(*start);
*(start)=temp;
// cout<<"SRT->"<<(*start)->info;


}
int countData(node *start)
{
int count=0;
struct node *p=start;

while(p!=NULL)
{

count++;
p=p->link;
}
return count;
}


void show(node *start)
{
while(start!=NULL)
{
cout<<start->info<<" ";
start=start->link;
}

}


main()
{
struct node *start=NULL;
// node *prev=NULL;
int num,i,j;

cout<<"Enter Number "<<i+1<<":";
cin>>num;
insertFirst(&start,1);
insertFirst(&start,2);
insertFirst(&start,3);
insertFirst(&start,4);
insertFirst(&start,num);
cout<<"\nThis List are:";
show(start);
//insertFirst(start,num);
// insert(start,num);

int a=countData(start);
cout<<"\nTotal Data Is:"<<a;

}