71 lines
1.1 KiB
C
71 lines
1.1 KiB
C
#include <stdio.h>
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#include <stdlib.h>
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typedef struct Node node;
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struct Node {
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int collegeid;
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struct Node *next;
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};
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void insert(node **last, int collegeid) {
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node *dst = malloc(sizeof(node));
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dst->collegeid = collegeid;
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if (*last == NULL)
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*last = dst;
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if ((*last)->next == NULL)
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(*last)->next = dst, dst->next = *last;
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else {
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dst->next = (*last)->next;
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(*last)->next = dst;
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}
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}
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void delete (node **last) {
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node *prev = NULL;
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if ((*last)->next == NULL)
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goto cleanup;
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prev = *last;
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while (prev->next != *last)
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prev = prev->next;
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if (prev->next->next == prev)
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prev->next = NULL;
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else
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prev->next = (*last)->next;
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cleanup:
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free(*last);
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*last = prev;
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}
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void display(node *last) {
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node *cur = last;
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while (cur->next != last) {
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printf("%d ", cur->next->collegeid);
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cur = cur->next;
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}
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printf("%d\n", last->collegeid);
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}
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int main() {
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node *last = NULL;
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insert(&last, 1);
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insert(&last, 4);
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insert(&last, 99);
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insert(&last, 1223);
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display(last);
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delete (&last);
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display(last);
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// free
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while (last != NULL)
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delete (&last);
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}
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