97 lines
1.6 KiB
C
97 lines
1.6 KiB
C
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#include <stdio.h>
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#include <stdlib.h>
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typedef struct Node {
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struct Node *next;
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struct Node *prev;
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int data;
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} Node;
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// Returns the head of the linked list
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Node *newLinkedList();
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// Returns a pointer to the next node
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Node *appendNode(Node *prev);
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// Prints the linked list in reverse order
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void printListReverse(Node *head);
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// Frees the list from memory
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void freeList(Node *head);
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int main(void) {
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// Get rows of input
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int rows;
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scanf("%d", &rows);
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Node *head;
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for (int i = 0; i < rows; i++) {
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head = newLinkedList();
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printListReverse(head);
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freeList(head);
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}
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return 0;
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}
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Node *newLinkedList() {
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Node *ptr, *head;
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// Initialize head
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head = malloc(sizeof(Node));
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head->prev = NULL;
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head->next = NULL;
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ptr = head;
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// Initialize list
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int data;
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scanf("%d", &data);
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while (data != -1) {
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ptr->data = data;
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ptr = appendNode(ptr);
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scanf("%d", &data);
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}
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return head;
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}
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Node *appendNode(Node *prev) {
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Node *node;
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node = malloc(sizeof(Node));
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prev->next = node;
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node->prev = prev;
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node->next = NULL;
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return node;
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}
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void printListReverse(Node *head) {
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// Can't use recursion because the output should be formatted
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Node *ptr = head;
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while (ptr->next != NULL) {
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ptr = ptr->next;
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}
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// ptr now points to the tail.
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ptr = ptr->prev;
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if (ptr != NULL) {
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printf("%d", ptr->data);
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ptr = ptr->prev;
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}
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while (ptr != NULL) {
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printf(" %d", ptr->data);
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ptr = ptr->prev;
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}
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printf("\n");
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}
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void freeList(Node *head) {
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if (head->next != NULL) {
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freeList(head->next);
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free(head);
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} else {
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free(head);
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}
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}
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