====== Linked List ======

  * [[http://cslibrary.stanford.edu/103/LinkedListBasics.pdf]]
  * [[https://linux.die.net/man/3/queue]]
  * [[https://linux.die.net/man/3/hsearch]]
  * [[https://linux.die.net/man/3/tsearch]]
  * [[https://linux.die.net/man/3/bsearch]]
  * [[https://linux.die.net/man/3/hcreate_r]]
  * [[https://github.com/mellowcandle/liblist/tree/master]]
  * [[https://gist.github.com/meylingtaing/11018042]]
  * [[https://mellowcandle.github.io/liblist/]]


----
===== Push =====
<code C>
// push.c - push() implementation
// gcc -std=c99 -Wall -Wextra -Werror -pedantic -o push push.c

// headp  : head pointer
// headpr : head pointer reference

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

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

void push(struct node **headpr, int n)
{
    struct node *newnode = malloc(sizeof(struct node));
    newnode->data = n;
    newnode->next = *headpr;
    *headpr = newnode;
}

int main()
{
    struct node *headp = NULL;
    push(&headp, 1);
    push(&headp, 2);
    push(&headp, 3);
    push(&headp, 4);
    push(&headp, 5);

    for (struct node *p = headp; p != NULL; p = p->next)
        printf("%d\n", p->data);

    return 0;
}
</code>

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----
===== Append =====

<code C>
// append.c - append() implementation
// gcc -std=c99 -Wall -Wextra -Werror -pedantic -o append append.c

// headp  : head pointer
// headpr : head pointer reference

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

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

void append(struct node **headpr, int n)
{
    struct node *newnode = malloc(sizeof(struct node));
    newnode->data = n;
    newnode->next = NULL;

    if (*headpr == NULL) {
        *headpr = newnode;
        return;
    }

    struct node *tailp;
    tailp = *headpr;
    while (tailp->next != NULL)
        tailp = tailp->next;
    tailp->next = newnode;
}

int main()
{
    struct node *headp = NULL;
    append(&headp, 1);
    append(&headp, 2);
    append(&headp, 3);
    append(&headp, 4);
    append(&headp, 5);

    for (struct node *p = headp; p != NULL; p = p->next)
        printf("%d\n", p->data);

    return 0;
}
</code>

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----
===== Append using Push =====

<code C>
// append-push.c - append() implementation using push()
// gcc -std=c99 -Wall -Wextra -Werror -pedantic -o append-push append-push.c

// headp  : head pointer
// headpr : head pointer reference

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

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

void push(struct node **headpr, int n)
{
    struct node *newnode = malloc(sizeof(struct node));
    newnode->data = n;
    newnode->next = *headpr;
    *headpr = newnode;
}

void append(struct node **headpr, int n)
{
    if (*headpr == NULL) {
        push(headpr, n);
        return;
    }

    struct node *tail;
    tail = *headpr;
    while (tail->next != NULL)
        tail = tail->next;

    push(&(tail->next), n);
}

int main()
{
    struct node *headp = NULL;

    push(&headp, 1);
    push(&headp, 2);
    push(&headp, 3);
    push(&headp, 4);

    append(&headp, 5);
    append(&headp, 6);
    append(&headp, 7);
    append(&headp, 8);

    for (struct node *p = headp; p != NULL; p = p->next)
        printf("%d\n", p->data);

    return 0;
}
</code>

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