Created
November 15, 2020 01:46
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Linked List in C
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#include <stdio.h> | |
#include <stdlib.h> | |
typedef struct Node { | |
int key; | |
struct Node* prev; | |
struct Node* next; | |
} Node; | |
typedef struct LinkedList { | |
Node* head; | |
} LinkedList; | |
Node* createNode(int key) { | |
Node* node = (Node *) malloc(sizeof(Node)); | |
node->key = key; | |
node->prev = NULL; | |
node->next = NULL; | |
return node; | |
} | |
LinkedList* createList() { | |
LinkedList* list = (LinkedList *) malloc(sizeof(LinkedList)); | |
list->head = NULL; | |
return list; | |
} | |
int printList(LinkedList *L) { | |
Node* x = L->head; | |
while (x != NULL) { | |
printf("key: %d\n", x->key); | |
x = x->next; | |
} | |
printf("\n\n"); | |
return 0; | |
} | |
LinkedList* insertKey(LinkedList *L, int k) { | |
Node* x = createNode(k); | |
if (L->head != NULL) { | |
L->head->prev = x; | |
} | |
x->next = L->head; | |
L->head = x; | |
return L; | |
} | |
Node* searchKey(LinkedList *L, int k) { | |
Node* x = L->head; | |
while (x != NULL && x->key != k) { | |
x = x->next; | |
} | |
return x; | |
} | |
LinkedList* deleteKey(LinkedList *L, int k) { | |
Node* x = searchKey(L, k); | |
if (x == NULL) { | |
printf("The key, %d, provided does not exist in the list.\n\n", k); | |
return L; | |
} | |
if (x->prev == NULL) { | |
L->head = x->next; | |
} else { | |
x->prev->next = x->next; | |
} | |
if (x->next != NULL) { | |
x->next->prev = x->next; | |
} | |
return L; | |
} | |
void printNode(Node* node) { | |
if (!node) { | |
printf("Node: NULL\n"); | |
} else { | |
printf("Node: %d\n", node->key); | |
} | |
} | |
int main() { | |
LinkedList* list = createList(); | |
insertKey(list, 1); | |
insertKey(list, 2); | |
insertKey(list, 3); | |
insertKey(list, 4); | |
printList(list); | |
deleteKey(list, 1); | |
printList(list); | |
return 0; | |
} |
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