Mega Code Archive
No sort, but reversing a [linked list]
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#include <stdio.h>
#include <stdlib.h>
#define MAX 10 /* max of 10 elements */
struct lnode {
int number;
struct lnode *next;
};
/* add a lnode at the beginning of the list */
void llist_add_begin(struct lnode **n, int val);
/* reverse the whole list */
void llist_reverse(struct lnode **n);
/* display the whole linked list */
void llist_display(struct lnode *n);
int main(void) {
struct lnode *new = NULL;
int i = 0;
/* insert some numbers */
for(i = 0; i <= MAX; i++)
llist_add_begin(&new, i);
printf("linked list before reversal:");
llist_display(new);
llist_reverse(&new);
printf("linked list after reversal:");
llist_display(new);
return 0;
}
/* add a lnode at the beginning of the list */
void llist_add_begin(struct lnode **n, int val) {
struct lnode *temp = NULL;
/* add new node */
temp = malloc(sizeof(struct lnode));
temp->number = val;
temp->next = *n;
*n = temp;
}
/* reverse the whole list */
void llist_reverse(struct lnode **n) {
struct lnode *a = NULL;
struct lnode *b = NULL;
struct lnode *c = NULL;
a = *n, b = NULL;
while(a != NULL) {
c = b, b = a, a = a->next;
b->next = c;
}
*n = b;
}
/* display the whole linked list */
void llist_display(struct lnode *n) {
while(n != NULL)
printf(" %d", n->number), n = n->next;
printf("\n");
}
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