Reverse a Linked List

Lab C Advanced 30 points

Build a list from n integers, reverse it in place by re-pointing the links, and print it.

Input

Line 1: n. Line 2: n integers.

Output

One line.

Example

Input

5
1 2 3 4 5

Output

5 4 3 2 1

Sample input available Sample output available

Editor

Hints

Walk the list keeping prev, cur and next; point cur->next back to prev.

Solution explanation

This three-pointer reversal is one of the most famous pointer exercises.

Show solution

#include <stdio.h>
#include <stdlib.h>

struct Node {
    int value;
    struct Node *next;
};

int main() {
    int n, x;
    struct Node *head = NULL, *tail = NULL;
    scanf("%d", &n);
    for (int i = 0; i < n; i++) {
        scanf("%d", &x);
        struct Node *node = malloc(sizeof(struct Node));
        node->value = x;
        node->next = NULL;
        if (head == NULL) head = node;
        else tail->next = node;
        tail = node;
    }
    struct Node *prev = NULL, *cur = head;
    while (cur != NULL) {
        struct Node *next = cur->next;
        cur->next = prev;
        prev = cur;
        cur = next;
    }
    head = prev;
    for (struct Node *p = head; p != NULL; p = p->next) printf("%d ", p->value);
    printf("\n");
    return 0;
}

Output

Answer