nd_sys_prog/homework07/list.c
2025-03-29 17:05:36 -04:00

83 lines
2 KiB
C

/* list.c: List Structure */
#include "list.h"
/* List Functions */
/**
* Create a List structure.
*
* @return Pointer to new List structure (must be deleted later).
**/
List * list_create() {
List *newList = calloc(1, sizeof(List)); // Use calloc to set everything to 0
newList->sentinel.next = &newList->sentinel;
newList->sentinel.prev = &newList->sentinel;
return newList;
}
/**
* Delete List structure.
*
* @param l Pointer to List structure.
* @param release Whether or not to release the string values.
**/
void list_delete(List *l, bool release) {
Node *current = l->sentinel.next; // Start with first node after sentinel node
while (current != &l->sentinel) {
Node *next = current->next;
node_delete(current, release); // Call node_delete and pass in release variable
current = next;
}
free(l);
}
/**
* Add new Value to back of List structure.
*
* @param l Pointer to List structure.
* @param v Value to add to back of List structure.
**/
void list_append(List *l, Value v) {
Node *appNode = node_create(v, &l->sentinel, l->sentinel.prev);
l->sentinel.prev->next = appNode;
l->sentinel.prev = appNode;
l->size++;
}
/**
* Remove Value at specified index from List structure.
*
* @param l Pointer to List structure.
* @param index Index of Value to remove from List structure.
*
* @return Value at index in List structure (-1 if index is out of bounds).
**/
Value list_pop(List *l, size_t index) {
if (index >= l->size) {
return (Value)-1L;
}
// Find the node based on index
Node *current = l->sentinel.next;
for (size_t i = 0; i < index; i++) {
current = current->next;
}
// Unlink the node
current->prev->next = current->next;
current->next->prev = current->prev;
Value v = current->value;
node_delete(current, false);
l->size--;
return v;
}
/* vim: set sts=4 sw=4 ts=8 expandtab ft=c: */