52 lines
1.1 KiB
C
52 lines
1.1 KiB
C
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#include <stdio.h>
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#include <stdlib.h>
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typedef struct _dclist * List;
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struct _dclist {
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int data;
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List next;
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List prev;
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};
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List init() {
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List initializer = malloc(sizeof(struct _dclist));
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initializer->data = 0;
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initializer->next = initializer;
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initializer->prev = initializer;
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return initializer;
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}
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void insert(int data, List list) {
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List head = list;
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while ( list->next != head ) { // if we have next, go to it.
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list = list->next;
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}
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list->next = malloc(sizeof(struct _dclist));
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head->prev = list->next;
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list->next->prev = list; // set the preview value;
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list->next->data = data;
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list->next->next = head;
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}
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void print(List list) {
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List head = list;
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while ( list->next != head) {
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list = list->next;
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printf("PREVIOUS VALUE: %d\n", list->prev->data);
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printf("CURRENT VALUE: %d\n", list->data);
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}
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printf("Is it circular? %d means yes\n", list->next->data);
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}
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int main(void) {
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List test = init();
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insert(10, test);
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insert(12, test);
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insert(13, test);
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insert(14, test);
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insert(15, test);
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print(test);
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return 0;
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}
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