Program to print all possible permutations of first n natural nos.

#include<iostream.h>
#include<conio.h>
#include<string.h>

int count=0;

//func to display the sequence
void dis(char a[],int n)
{
for(int jk=n-1;jk>=0;jk--)
{
cout<<a[jk];
}
cout<<"
";
}

//function to left shift last n elements
//of the array by one position
void shift(char a[],int n)
{
char s;
s=a[n-1];
for(int i=n-1;i>0;i--)
a[i]=a[i-1];
a[0]=s;
}

//func to find all possible arrangements
void per(char a[],int m,int n)
{
for(int i=0;i<m;i++)
{
if(m>1)
{
shift(a,m);
per(a,m-1,n); //genetrating the tree
}
else
{
dis(a,n); //displaying the leaf nodes of the tree
count++;
}
}
}


void main()
{
// char *a;
int n;
clrscr();

cout<<"Enter a no : ";
cin>>n;

char *a = new (char[n]);

for(int i=0;i<n;i++)
a[i] = n-i+48;

// dis(a,n);

cout<<"Possible permutations are :
";
per(a,n,n);
cout<<"Total No Of Permutations Is "<<count;
getch();
}

OUTPUT
------

Enter a no : 3
Possible permutations are :
213
231
321
312
132
123
Total No Of Permutations Is 6