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  1. #include <stddef.h>
  2. #include <stdlib.h>
  3. #include <stdio.h>
  4.  
  5. typedef struct s_node s_node;
  6. typedef struct s_list s_list;
  7. struct s_node {
  8.     s_node * next;
  9.   };
  10. struct s_list {
  11.     s_node * tail;
  12.   };
  13.  
  14. s_node * append_node(s_list * list) {
  15.     s_node * new_node;
  16.  
  17.     new_node = malloc(sizeof *new_node);
  18.     if (!new_node)
  19.       return NULL;
  20.  
  21.     /* Check for empty list */
  22.     if (!list->tail) {
  23.         new_node->next = new_node;
  24.         list->tail = new_node;
  25.         return new_node;
  26.       }
  27.  
  28.     new_node->next = list->tail->next;
  29.     list->tail->next = new_node;
  30.     list->tail = new_node;
  31.     return new_node;
  32.   }
  33.  
  34. s_node * head_node(s_list * list) {
  35.     /* Check for empty list */
  36.     if (!list->tail)
  37.       return NULL;
  38.  
  39.     return list->tail->next;
  40.   }
  41.  
  42. int list_length(s_list * list) {
  43.     s_node * node;
  44.     int len = 0;
  45.  
  46.     for (node = head_node(list); node; node = node->next) {
  47.         printf(
  48.             "%p->next == %p%s\n",
  49.             (void *) node,
  50.             (void *) node->next,
  51.             node == list->tail ? "" : " &&"
  52.           );
  53.         ++len;
  54.         if (node == list->tail)
  55.           break;
  56.         continue;
  57.       }
  58.     return len;
  59.   }
  60.  
  61. int main(void) {
  62.     s_list list[1];
  63.  
  64.     list->tail = NULL;
  65.  
  66.     if (append_node(list) && append_node(list) && append_node(list))
  67.       printf("Total nodes: %d\n", list_length(list));
  68.  
  69.     return EXIT_SUCCESS;
  70.   }
Success #stdin #stdout 0.01s 1852KB
comments (?)
stdin 
Standard input is empty
stdout 
0x9918008->next == 0x9918018 &&
0x9918018->next == 0x9918028 &&
0x9918028->next == 0x9918008
Total nodes: 3
https://ideone.com/aNGBA
language:
C (gcc 8.3)
created:
14 years ago
visibility:
public

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