blog/static/files/algorithms/time-complexity/extend/dynlist.c

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#include "dynlist.h"
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
void dynamic_array_init(struct dynamic_array_t *arr, size_t size)
{
if (arr == NULL)
{
return;
}
arr->data = NULL;
arr->count = 0;
arr->capacity = 0;
arr->size = size;
}
void dynamic_array_destroy(struct dynamic_array_t *arr)
{
if (arr == NULL)
{
return;
}
if (arr->data != NULL)
{
free(arr->data);
arr->data = NULL;
}
arr->count = 0;
arr->capacity = 0;
}
void *dynamic_array_at(struct dynamic_array_t *arr, size_t index)
{
if (arr == NULL || index >= arr->count)
{
return NULL;
}
return arr->data + index * arr->size;
}
void *dynamic_array_front(struct dynamic_array_t *arr)
{
if (arr == NULL || arr->count < 1)
{
return NULL;
}
return arr->data;
}
void *dynamic_array_back(struct dynamic_array_t *arr)
{
if (arr == NULL || arr->count < 1)
{
return NULL;
}
return arr->data + (arr->count - 1) * arr->size;
}
/**
* @brief Resize the dynamic array when needed.
* @param arr Array to be resized.
* @returns <code>true</code> if resizing was successful or array was not resized,
* <code>false</code> otherwise.
*/
static bool dynamic_array_resize(struct dynamic_array_t *arr)
{
if (arr == NULL || arr->count < arr->capacity)
{
return true;
}
size_t new_capacity = arr->capacity ? (arr->capacity * 2) : 16;
void *new_data = realloc(arr->data, new_capacity * arr->size);
if (new_data == NULL)
{
// failed to reallocate memory
return false;
}
arr->data = new_data;
arr->capacity = new_capacity;
return true;
}
bool dynamic_array_push_back(struct dynamic_array_t *arr, void *data)
{
if (arr == NULL || data == NULL)
{
return false;
}
if (!dynamic_array_resize(arr))
{
// failed to reallocate memory
return false;
}
memcpy(dynamic_array_at(arr, arr->count), data, arr->size);
arr->count++;
return true;
}
void dynamic_array_pop_back(struct dynamic_array_t *arr)
{
if (arr == NULL || arr->count < 1)
{
return;
}
arr->count--;
}
void dynamic_array_extend(struct dynamic_array_t *arr, struct dynamic_array_t *src)
{
if (arr == NULL || src == NULL)
{
return;
}
for (size_t i = 0; i < src->count; i++)
{
dynamic_array_push_back(arr, dynamic_array_at(src, i));
}
}
void dynamic_array_clear(struct dynamic_array_t *arr)
{
if (arr == NULL)
{
return;
}
arr->count = 0;
}