Add after an element in a linked list

main.c

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

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

void deallocate(Node** root) {
    Node* curr = *root;
    while (curr != NULL) {
        Node* aux = curr;
        curr = curr->next;
        free(aux);
    }
    *root = NULL;
}

void insert_end(Node** root, int value) {
    Node* new_node = malloc(sizeof(Node));
    if (new_node == NULL) {
        exit(1);
    }
    new_node->next = NULL;
    new_node->x = value;
    
    if (*root == NULL) {
        *root = new_node;
        return;
    }
    
    Node* curr = *root;
    while (curr->next != NULL) {
        curr = curr->next;
    }
    curr->next = new_node;
}

void insert_beginning(Node** root, int value) {
    Node* new_node = malloc(sizeof(int));
    if (new_node == NULL) {
        exit(3);
    }
    
    new_node->x = value;
    new_node->next = *root;
    
    *root = new_node;
}

void insert_after(Node* node, int value) {
    Node* new_node = malloc(sizeof(Node));
    if (new_node == NULL) {
        exit(1);
    }
    
    new_node->x = value;
    new_node->next = node->next;
    node->next = new_node;
}

int main(int argc, char* argv[]) {
    Node* root = NULL;
    
    insert_end(&root, -2);
    insert_end(&root, 11);
    insert_end(&root, 22);
    insert_beginning(&root, 30);
    insert_after(root->next, 55);
    
    for (Node* curr = root; curr != NULL; curr = curr->next) {
        printf("%d\n", curr->x);
    }
    
    deallocate(&root);
    
    return 0;
}