src/lib/ll.c

   1 #include "src/lib/ll.h"\r
   2 \r
   3 void print_list(node_t * head)\r
   4 {\r
   5         node_t * current = head;\r
   6 \r
   7         while (current != NULL)\r
   8         {\r
   9                 printf("[%u]    %d\n", current->id, current->val);\r
  10                 current = current->next;\r
  11         }\r
  12 }\r
  13 \r
  14 void pushe(node_t * head, int val)\r
  15 {\r
  16         node_t * current = head;\r
  17         current->id = head->id;\r
  18         current->next->id = current->id+1;\r
  19 \r
  20         while (current->next != NULL)\r
  21         {\r
  22                 current->next->id = current->id;\r
  23                 current = current->next;\r
  24                 current->id++;\r
  25         }\r
  26 \r
  27         // now we can add a new variable\r
  28         current->next = malloc(sizeof(node_t));\r
  29         current->next->val = val;\r
  30         current->next->next = NULL;\r
  31         current->next->id++;\r
  32 }\r
  33 \r
  34 void pushs(node_t ** head, int val)\r
  35 {\r
  36         node_t * new_node;\r
  37         new_node = malloc(sizeof(node_t));\r
  38 \r
  39         new_node->val = val;\r
  40         new_node->next = *head;\r
  41         *head = new_node;\r
  42 }\r
  43 \r
  44 int pop(node_t ** head)\r
  45 {\r
  46         int retval = -1;\r
  47         node_t * next_node = NULL;\r
  48 \r
  49         if (*head == NULL) {\r
  50                 return -1;\r
  51         }\r
  52 \r
  53         next_node = (*head)->next;\r
  54         retval = (*head)->val;\r
  55         free(*head);\r
  56         *head = next_node;\r
  57 \r
  58         return retval;\r
  59 }\r
  60 \r
  61 int remove_last(node_t * head)\r
  62 {\r
  63         int retval = 0;\r
  64         node_t * current;\r
  65 \r
  66         /* if there is only one item in the list, remove it */\r
  67         if (head->next == NULL) {\r
  68                 retval = head->val;\r
  69                 free(head);\r
  70                 return retval;\r
  71         }\r
  72 \r
  73         /* get to the last node in the list */\r
  74         current = head;\r
  75         while (current->next->next != NULL) {\r
  76                 current = current->next;\r
  77         }\r
  78 \r
  79         /* now current points to the last item of the list, so let's remove current->next */\r
  80         retval = current->next->val;\r
  81         free(current->next);\r
  82         current->next = NULL;\r
  83         return retval;\r
  84 \r
  85 }\r
  86 \r
  87 int remove_by_index(node_t ** head, int n)\r
  88 {\r
  89         int i = 0;\r
  90         int retval = -1;\r
  91         node_t * current = *head;\r
  92         node_t * temp_node = NULL;\r
  93 \r
  94         if (n == 0) {\r
  95                 return pop(head);\r
  96         }\r
  97 \r
  98         for (i = 0; i < n-1; i++) {\r
  99                 if (current->next == NULL) {\r
 100                         return -1;\r
 101                 }\r
 102                 current = current->next;\r
 103         }\r
 104 \r
 105         temp_node = current->next;\r
 106         retval = temp_node->val;\r
 107         current->next = temp_node->next;\r
 108         free(temp_node);\r
 109 \r
 110         return retval;\r
 111 }\r