Radix Sort Algorithm

/* C program to sort an array using radix sort LINKED LIST implementation*/

#include < stdio.h>
#include < conio.h>
#include < stdlib.h>

void radix(int a[],int n,int m)
{
typedef struct node
{
int data;
struct node * next;
}NODE;

NODE * ptr,*start,*prev;
NODE *front[10], *rear[10];
int k=1,i,j,y,p;;
/*creating initial linked list*/
start=NULL;
for(i=0;i< n;++i)
{
ptr=(NODE *)malloc(sizeof(NODE));
ptr->data=a[i];
ptr->next=NULL;
if(start==NULL)
start=ptr;
else
prev->next=ptr;
prev=ptr;
}

/*radix sort*/

for(i=1;i< =m;++i)
{
for(j=0;j< 10;++j)
front[j]=NULL;
/*placing elements into queues*/
ptr=start;
while(ptr!=NULL)
{y=ptr->data/k %10;/*y is the digit*/
if(front[y]==NULL)
{
front[y]=ptr;
rear[y]=ptr;
}
else
{
rear[y]->next=ptr;
rear[y]=ptr;
}

ptr=ptr->next;
}

start=NULL;
for(j=0;j< 10;++j)
if(front[j]!=NULL)
{
if(start==NULL)
start=front[j];
else rear[p]->next=front[j];
p=j;
}
rear[p]->next=NULL;
k=k*10;
}
/*copying back to array*/
ptr=start;
for(i=0;i< n;++i,ptr=ptr->next)
a[i]=ptr->data;

}

void main()
{
int a[100],n,i,m;
char temp;
do
{
clrscr();
printf("===========================RADIX SORT===========================================\n");
printf("ENTER NUMBER OF NUMBERS AND NUMBER OF DIGITS\n");
scanf("%d%d",&n,&m);
printf("ENTER ELEMENTS\n");
for(i=0;i< n;++i)
scanf("%d",&a[i]);
radix(a,n,m);
printf("SORTED LIST\n");
for(i=0;i< n;++i)
printf("%d ",a[i]);
printf("\nDO YOU wish to continue?[y/n]\n");
scanf("%c",&temp);


}while(temp=='y'|| temp=='Y');
printf("\n---------------------------------------------------------------------------------\n");
getch();
}
/*OUTPUT:
===========================RADIX SORT===========================================

Enter number of numbers and number of digits
4
2
enter elements
25
65
35
45
sorted list
25 35 45 65
Do you wish to continue?[y/n]
n
--------------------------------------------------------------------------------*/