Friday, November 12, 2010

/* Program to sort a linked list by swapping data.*/

/* Program to sort a linked list by swapping data.*/
#include <stdio.h>
#include <conio.h>
#include <alloc.h>

/* structure containing a data part and link part */
struct node
{
 int data ;
 struct node *link ;
} *newnode, *start, *visit ;

void getdata( ) ;
void append ( struct node **, int ) ;
void displaylist( ) ;
int count ( struct node * ) ;
void selection_sort ( int ) ;
void bubble_sort ( int ) ;

void main( )
{
 int n ;

 getdata( ) ;
 clrscr( ) ;
 printf ( "Linked List Before Sorting: " ) ;
 displaylist( ) ;

 n = count ( start ) ;
 selection_sort ( n ) ;
 printf ( "\nLinked List After Selection Sorting: " ) ;
 displaylist( ) ;
 getch( ) ;

 getdata( ) ;
 clrscr( ) ;
 printf ( "Linked List Before Sorting: " ) ;
 displaylist( ) ;

 n = count ( start ) ;
 bubble_sort ( n ) ;
 printf ( "\nLinked List After Bubble Sorting: " ) ;
 displaylist( ) ;
 getch( ) ;
}

void getdata( )
{
 int val, n ;
 char ch ;
 struct node *new ;

 clrscr( ) ;
 new = NULL ;
 do
 {
  printf ( "\nEnter a value: " ) ;
  scanf ( "%d", &val ) ;

  append ( &new, val ) ;
  printf ( "\nAny More Nodes (Y/N): " ) ;
  ch = getche( ) ;
 } while ( ch == 'y' || ch == 'Y' ) ;

 start = new ;
}

/* adds a node at the end of a linked list */
void append ( struct node **q, int num )
{
 struct node *temp ;
 temp = *q ;

 if ( *q == NULL ) /* if the list is empty, create first node */
 {
  *q = malloc ( sizeof ( struct node ) ) ;
  temp = *q ;
 }
 else
 {
  /* go to last node */
  while ( temp -> link != NULL )
   temp = temp -> link ;

  /* add node at the end */
  temp -> link = malloc ( sizeof ( struct node ) ) ;
  temp = temp -> link ;
 }

 /* assign data to the last node */
 temp -> data = num ;
 temp -> link = NULL ;
}

/* displays the contents of the linked list */
void displaylist( )
{
 visit = start ;

 /* traverse the entire linked list */
 while ( visit != NULL )
 {
  printf ( "%d ", visit -> data ) ;
  visit = visit -> link ;
 }
}

/* counts the number of nodes present in the linked list */
int count ( struct node * q )
{
 int c = 0 ;

 /* traverse the entire linked list */
 while ( q != NULL )
 {
  q = q -> link ;
  c++ ;
 }

 return c ;
}

void selection_sort ( int n )
{
 int i, j, k, temp ;
 struct node *p, *q ;

 p = start ;
 for ( i = 0 ; i < n - 1 ; i++ )
 {
  q = p -> link ;

  for ( j = i + 1 ; j < n ; j++ )
  {
   if ( p -> data > q -> data )
   {
    temp = p -> data ;
    p -> data = q -> data ;
    q -> data = temp ;
   }
   q = q -> link ;
  }
  p = p -> link ;
 }
}

void bubble_sort ( int n )
{
 int i, j, k, temp ;
 struct node *p, *q ;

 k = n ;
 for ( i = 0 ; i < n - 1 ; i++, k-- )
 {
  p = start ;
  q = p -> link ;

  for ( j = 1 ; j < k ; j++ )
  {
   if ( p -> data > q -> data )
   {
    temp = p -> data ;
    p -> data = q -> data ;
    q -> data = temp ;
   }
   p = p -> link ;
   q = q -> link ;
  }
 }
}

No comments: