95 lines
1.5 KiB
C
95 lines
1.5 KiB
C
#include <stdio.h>
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#include <stdlib.h>
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typedef struct Student student;
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struct Student {
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int sid;
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struct Student *next;
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};
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void insert(student **head, int idx, uint sid) {
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student *new = malloc(sizeof(student));
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new->sid = sid;
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int i = 0;
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student *prev = NULL, *cur = *head;
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for (int i = 0;; i++) {
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if (i == idx) {
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if (prev != NULL)
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prev->next = new;
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else
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*head = new;
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new->next = cur;
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return;
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}
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if (cur == NULL)
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return;
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prev = cur;
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cur = cur->next;
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}
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printf("Index %d does not exist\n", idx);
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return;
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}
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void delete (student **head, int idx) {
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student *prev = NULL, *cur = *head;
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for (int i = 0; cur != NULL; i++) {
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if (i == idx) {
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if (prev != NULL)
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prev->next = cur->next;
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else
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*head = cur->next;
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free(cur);
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return;
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}
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prev = cur;
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cur = cur->next;
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}
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printf("Index %d does not exist\n", idx);
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return;
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}
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void reverse(student **head) {
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student *prev = NULL, *cur = *head;
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while (cur->next != NULL) {
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student *next = cur->next;
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cur->next = prev;
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prev = cur;
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cur = next;
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}
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cur->next = prev;
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*head = cur;
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return;
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}
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int main() {
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student *head = NULL;
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insert(&head, 0, 1);
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insert(&head, 1, 2002);
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insert(&head, 2, -9);
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insert(&head, 3, 52);
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insert(&head, 1, 4);
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delete (&head, 2);
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reverse(&head);
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student *cur = head;
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while (cur != NULL) {
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printf("%d ", cur->sid);
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cur = cur->next;
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}
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// free
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while (head != NULL)
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delete(&head, 0);
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}
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