Programma per dividere l'elenco collegato

Implementazione

L'implementazione di questo algoritmo è fornita di seguito:

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

struct node {
   int data;
   struct node *next;
};

struct node *even = NULL;
struct node *odd = NULL;
struct node *list = NULL;

//Create Linked List
void insert(int data) {
   // Allocate memory for new node;
   struct node *link = (struct node*) malloc(sizeof(struct node));
   struct node *current;

   link->data = data;
   link->next = NULL;

   if(list == NULL) {
      list = link;
      return;
   }
   current = list;

   while(current->next!=NULL)
      current = current->next;

   // Insert link at the end of the list
   current->next = link; 
}

void display(struct node *head) {
   struct node *ptr = head;

   printf("[head] =>");
   //start from the beginning
   while(ptr != NULL) {        
      printf(" %d =>",ptr->data);
      ptr = ptr->next;
   }

   printf(" [null]\n");
}

void split_list() {
   // Allocate memory for new node;
   struct node *link;
   struct node *current;

   while(list != NULL) {
      struct node *link = (struct node*) malloc(sizeof(struct node));

      link->data = list->data;
      link->next = NULL;

      if(list->data%2 == 0) {
         if(even == NULL) {
            even = link;
            list = list->next;
            continue;
         } else {
            current = even;

            while(current->next != NULL)
            current = current->next;

            // Insert link at the end of the list
            current->next = link; 
         }
         list = list->next;
      
      } else {
         if(odd == NULL) {
            odd = link;
            list = list->next;
            continue;
         } else {
            current = odd;
            while(current->next!=NULL)
            current = current->next;

            // Insert link at the end of the list
            current->next = link; 

         }
         list = list->next;
      }
   }
}
    
int main() {
   int i;

   for(i = 1; i <= 10; i++)
      insert(i);

   printf("Complete list: \n");
   display(list);

   split_list();

   printf("\nOdd  : ");
   display(odd);

   printf("Even : ");
   display(even);

   return 0;
}

Produzione

Il risultato del programma dovrebbe essere:

Complete list:
[head] => 1 => 2 => 3 => 4 => 5 => 6 => 7 => 8 => 9 => 10 => [null]

Odd  : [head] => 1 => 3 => 5 => 7 => 9 => [null]
Even : [head] => 2 => 4 => 6 => 8 => 10 => [null]