Talk:Singly-linked list/Element removal: Difference between revisions
Talk:Singly-linked list/Element removal (view source)
Revision as of 16:16, 30 November 2018
, 5 years ago→Taste: new section
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This needs a task description and goal. While it may be a valuable addition to have such a task, this does not yet meet minimum criteria. See [[Singly-linked_list/Element_insertion]] for possible verbiage (edited to suit) --[[User:Thundergnat|Thundergnat]] ([[User talk:Thundergnat|talk]]) 16:20, 27 October 2016 (UTC)
== Taste ==
In a 2016 TED talk, interview with Chris Anderson, Linus Torvalds provides an example of element removal in a singly-linked list while discussing good taste in coding. He got rid of the if ... then statement to handle a special case. See [https://www.ted.com/talks/linus_torvalds_the_mind_behind_linux#t-933770 at 15'40" in the talk].
<lang C>
remove_list_entry(entry)
{
// The "indirect" pointer points to the
// *address* of the thing we'll update
indirect = &head;
// Walk the list, looking for the thing that
// points tot the entry we want to remove
while ((*indirect) != entry)
indirect = &(*indirect)->next;
// .. and just remove it
*indirect = entry->next;
}
</lang>
Slightly adapted to make the above code compile and run.
<lang C>
#include <stdio.h>
typedef struct node {
int val;
struct node* next;
} node_t;
node_t* head = NULL;
node_t** indirect;
void remove_list_entry(node_t* entry)
{
// The "indirect" pointer points to the
// *address* of the thing we'll update
indirect = &head;
// Walk the list, looking for the thing that
// points tot the entry we want to remove
while ((*indirect) != entry)
indirect = &(*indirect)->next;
// .. and just remove it
*indirect = entry->next;
}
int main()
{
head = malloc(sizeof(node_t));
head->val = 1;
head->next = malloc(sizeof(node_t));
head->next->val = 2;
head->next->next = NULL;
remove_list_entry(head);
return 0;
}
</lang>
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