Linked List Magic

linked_list.c

/**
 * Simple example of linked lists in C. The special part is the use of a pointer to a pointer
 * which very elegantly can remove a node anywhere in the list without special case handling.
 */
#include <stdio.h>
#include <stdint.h>

typedef struct ll_node_s
{
    struct ll_node_s *mpNext;
    uint32_t data;
} ll_node_t;

void removeNode(ll_node_t **ptr, ll_node_t const *target)
{
    while(*ptr != target)
    {
        ptr = &((*ptr)->mpNext);
    }

    *ptr = (*ptr)->mpNext;
}

void printList(ll_node_t const *ptr)
{
    while(ptr != NULL)
    {
        fprintf(stdout, "%d ", ptr->data);
        ptr = ptr->mpNext;
    }
    fputc('\n', stdout);
}

int main()
{
    ll_node_t Node0 = { NULL, 0};
    ll_node_t Node1 = { &Node0, 1};
    ll_node_t Node2 = { &Node1, 2};
    ll_node_t Node3 = { &Node2, 3};
    ll_node_t Node4 = { &Node3, 4};
    ll_node_t Node5 = { &Node4, 5};

    ll_node_t *myList = &Node5;
    printList(myList);

    removeNode(&myList, &Node3);
    printList(myList);

    return 0;
}