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#include "linked_list.h"
#include <stdlib.h>
#include <stdio.h>
void append(struct list_item *first, int x) {
// find the last element
struct list_item *current = first;
while (current->next) {
current = current->next;
}
// insert after
struct list_item *new = malloc(sizeof(struct list_item));
new->value = x;
new->next = NULL;
current->next = new;
}
void prepend(struct list_item *first, int x) {
// the first element is a head-element so we insert after it
struct list_item *new = malloc(sizeof(struct list_item));
new->value = x;
new->next = first->next;
first->next = new;
}
void print(struct list_item *first) {
// skip printing the head
struct list_item *current = first->next;
while (current) {
printf("%d ", current->value);
current = current->next;
}
printf("\n");
}
void input_sorted(struct list_item *first, int x) {
struct list_item *current = first;
// find the first element in the list larger than x
// (we check current->next since we want to insert after current)
// if we reach the end (!current->next) we insert after current
while (current->next && current->next->value <= x) {
current = current->next;
}
struct list_item *new = malloc(sizeof(struct list_item));
new->value = x;
new->next = current->next;
current->next = new;
}
void clear(struct list_item *first) {
// don't clear head
struct list_item *current = first->next;
if (!current) {
// empty list, don't free anything
return;
}
struct list_item *next;
while (current) {
next = current->next;
free(current);
current = next;
}
first->next = NULL;
}
int main(int argc, char **argv) {
// head element
struct list_item root;
root.value = -1;
root.next = NULL;
// empty clears
clear(&root);
clear(&root);
print(&root);
// short append
append(&root, 1);
append(&root, 2);
append(&root, 3);
print(&root);
clear(&root);
// short prepend
prepend(&root, 1);
prepend(&root, 2);
prepend(&root, 3);
print(&root);
clear(&root);
// mix append prepend
append(&root, 1);
append(&root, 2);
prepend(&root, 4);
append(&root, 3);
prepend(&root, 5);
print(&root);
clear(&root);
//// input_sorted
append(&root, 10);
append(&root, 20);
append(&root, 30);
print(&root);
// in the middle
input_sorted(&root, 15);
input_sorted(&root, 25);
// at the back (new largest element)
input_sorted(&root, 35);
// at the front
input_sorted(&root, 5);
print(&root);
clear(&root);
print(&root);
}
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