C语言单链表实现：增删查操作

#include <stdio.h> #include <stdlib.h>

typedef struct Node { int data; struct Node *next; } Node;

typedef struct LinkedList { Node *head; } LinkedList;

void initialize(LinkedList *list) { list->head = NULL; }

void insert(LinkedList *list, int value) { Node *newNode = (Node *)malloc(sizeof(Node)); newNode->data = value; newNode->next = NULL;

if (list->head == NULL)
{
    list->head = newNode;
}
else
{
    Node *current = list->head;
    while (current->next != NULL)
    {
        current = current->next;
    }
    current->next = newNode;
}

}

void print(LinkedList *list) { Node *current = list->head; while (current != NULL) { printf('%d ', current->data); current = current->next; } printf(' '); }

int search(LinkedList *list, int value) { Node *current = list->head; int position = 1;

while (current != NULL)
{
    if (current->data == value)
    {
        return position;
    }
    current = current->next;
    position++;
}

return 0;

}

void insertAtPosition(LinkedList *list, int position, int value) { Node *newNode = (Node *)malloc(sizeof(Node)); newNode->data = value; newNode->next = NULL;

if (position == 1)
{
    newNode->next = list->head;
    list->head = newNode;
}
else
{
    Node *current = list->head;
    int currentPosition = 1;
    while (currentPosition < position - 1 && current != NULL)
    {
        current = current->next;
        currentPosition++;
    }

    if (current == NULL)
    {
        printf('Invalid position

'); return; }

    newNode->next = current->next;
    current->next = newNode;
}

}

void deleteAtPosition(LinkedList *list, int position) { if (position == 1) { Node *temp = list->head; list->head = list->head->next; free(temp); } else { Node *current = list->head; int currentPosition = 1; while (currentPosition < position - 1 && current != NULL) { current = current->next; currentPosition++; }

    if (current == NULL || current->next == NULL)
    {
        printf('Invalid position

'); return; }

    Node *temp = current->next;
    current->next = current->next->next;
    free(temp);
}

}

int main() { LinkedList list; initialize(&list);

int value;
printf('Enter values to insert into linked list (enter -1 to stop): ');
while (scanf('%d', &value) == 1 && value != -1)
{
    insert(&list, value);
}

printf('Linked list: ');
print(&list);

int searchValue;
printf('Enter value to search: ');
scanf('%d', &searchValue);
int position = search(&list, searchValue);
if (position == 0)
{
    printf('Value not found

'); } else { printf('Value found at position %d ', position); }

int insertValue, insertPosition;
printf('Enter value to insert: ');
scanf('%d', &insertValue);
printf('Enter position to insert: ');
scanf('%d', &insertPosition);
insertAtPosition(&list, insertPosition, insertValue);

printf('Linked list after insertion: ');
print(&list);

int deletePosition;
printf('Enter position to delete: ');
scanf('%d', &deletePosition);
deleteAtPosition(&list, deletePosition);

printf('Linked list after deletion: ');
print(&list);

return 0;