A set of linked list functions

linked_list.c

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

struct ListNode {
    int data;
    struct ListNode *next;
};

struct ListNode *listCreat();
void listPrint(struct ListNode *head );
struct ListNode *listElementDelete(struct ListNode *head );
struct ListNode *listReverse( struct ListNode *head );

int main() {
    struct ListNode *head;

    head = listCreat();
    listPrint(head);

    return 0;
}

/*******************************************************************************/

struct ListNode *listCreat() {
    struct ListNode *head = (struct ListNode *) malloc(sizeof(struct ListNode));
    struct ListNode *current = head;
    struct ListNode *tail = head;
    int firstLoop = 1;
    for (int n;; current = current->next) {
        scanf("%d", &n);
        if (n == -1) {
            if (firstLoop) {
                free(head);
                head = NULL;
            }
            break;
        }
        current->data = n;
        current->next = (struct ListNode *) malloc(sizeof(struct ListNode));
        tail = current;
        firstLoop = 0;
    }
    if (firstLoop)
        return NULL;
    free(tail->next);
    tail->next = NULL;
    return head;
}

void listPrint(struct ListNode *head ) {
    struct ListNode *p = head;
    while (p) {
        printf("%d ", p->data);
        p = p->next;
    }
    printf("\n");
}

struct ListNode *listCut( struct ListNode **originalHead ) {
    if (*originalHead == NULL)
        return NULL;

    struct ListNode *targetHead = NULL;
    struct ListNode *targetCurrent = targetHead;
    struct ListNode *previous = NULL;
    for (struct ListNode *current = *originalHead; current != NULL;) {
        if (current->data % 2 == 1) {                                              // Change this to what you want to cut
            if(targetHead == NULL) {
                targetHead = (struct ListNode *)malloc(sizeof(struct ListNode));
                targetHead->data = current->data;
                targetHead->next = NULL;
                targetCurrent = targetHead;
            }
            else {
                targetCurrent->next = (struct ListNode *)malloc(sizeof(struct ListNode));
                targetCurrent = targetCurrent->next;
                targetCurrent->data = current->data;
                targetCurrent->next = NULL;
            }

            if (current == *originalHead) {
                struct ListNode *temp = current->next;
                free(current);
                current = temp;
                *originalHead = current;
            }
            else {
                struct ListNode *temp = current->next;
                free(current);
                current = temp;
                previous->next = current;
            }
        }
        else {
            previous = current;
            current = current->next;
        }
    }
    return targetHead;
}

struct ListNode *listElementDelete(struct ListNode *head ) {
    struct ListNode* moveTo = NULL;
    struct ListNode* previous = NULL;
    for (struct ListNode* p = head; p != NULL; ) {
        if (p->data % 2 == 0) {                                         // Change this to what you want to delete
            if (p == head) {
                moveTo = p->next;
                head = p->next;
                free(p);
                p = NULL;
                previous = p;
            }
            else {
                moveTo = p->next;
                previous->next = p->next;
                free(p);
                p = NULL;
            }
        }
        else {
            previous = p;
            moveTo = p->next;
        }
        p = moveTo;
    }
    return head;
}

struct ListNode *listReverse( struct ListNode *head ) {
    struct ListNode* current = head;
    struct ListNode* next = head;
    struct ListNode* previous = NULL;
    for (current = head; current != NULL; current = next) {
        next = current->next;
        current->next = previous;
        previous = current;
    }
    return previous;
}