Нужна помощь! Даю максимальное количество баллов! Язык программирования си (с функцией main) . Надо создать двусвязные списки. Функции: добавление элемента в начало, конец, в n-ую позицию. Очистка всего списка, очистка n-ого элемента в списке.
Умоляю, помогите!!!! Если можно, то с объяснением, дам лучший ответ!!!
Ответы
Ответ:
#include <stdio.h>
#include <stdlib.h>
typedef struct List List;
typedef struct Node Node;
struct List
{
unsigned int size;
Node* head;
Node* tail;
};
struct Node
{
int data;
Node* pNext;
Node* pPrev;
};
void init(List* list)
{
list->head = NULL;
list->tail = NULL;
list->size = 0;
}
void push_back(List* list, int data)
{
Node* new_node = (Node*) malloc(sizeof(Node));
if (new_node == NULL) return;
new_node->data = data;
new_node->pNext = NULL;
new_node->pPrev = NULL;
if (list->head == NULL)
{
list->head = new_node;
list->tail = new_node;
}
else
{
new_node->pPrev = list->tail;
list->tail->pNext = new_node;
list->tail = new_node;
}
list->size++;
}
void push_front(List* list, int data)
{
Node* new_node = (Node*) malloc(sizeof(Node));
if (new_node == NULL) return;
new_node->data = data;
new_node->pNext = NULL;
new_node->pPrev = NULL;
if (list->head == NULL)
{
list->head = new_node;
list->tail = new_node;
}
else
{
new_node->pNext = list->head;
list->head->pPrev = new_node;
list->head = new_node;
}
list->size++;
}
void insert(List* list, unsigned int index, int data)
{
if (index > list->size) return;
if (index == 0)
{
push_front(list, data);
return;
}
if (index == list->size)
{
push_back(list, data);
return;
}
Node* current = list->head;
for (unsigned int i = 0; i < index - 1; i++)
{
current = current->pNext;
}
Node* new_node = (Node*) malloc(sizeof(Node));
if (new_node == NULL) return;
new_node->data = data;
new_node->pNext = current->pNext;
new_node->pPrev = current;
current->pNext->pPrev = new_node;
current->pNext = new_node;
list->size++;
}
void deleteAt(List* list, unsigned int index)
{
if (list->head == NULL) return;
Node* current = list->head;
unsigned int counter = 0;
while (counter <= index)
{
if (counter >= list->size) return;
if (counter == index)
{
if (current->pPrev != NULL)
{
current->pPrev->pNext = current->pNext;
}
else
{
list->head = current->pNext;
}
if (current->pNext != NULL)
{
current->pNext->pPrev = current->pPrev;
}
else
{
list->tail = current->pPrev;
}
free(current);
list->size--;
break;
}
current = current->pNext;
counter++;
}
}
void deleteList(List* list)
{
Node* current = list->head;
while (current != NULL)
{
Node* next = current->pNext;
free(current);
current = next;
}
}
Объяснение:
В main: (приклад)
List name;
init(&name);
push_back(&name);
З тебе краща відповідь