Insert at the Front

Lab C Beginner 10 points

Read n integers, inserting each at the front of a linked list. Print the list values separated by spaces (they come out reversed) and the length.

Input

Line 1: n. Line 2: n integers.

Output

Two lines.

Example

Input

4
1 2 3 4

Output

4 3 2 1
4

Sample input available Sample output available

Editor

Hints

The new node's next is the old head; the new node becomes the head.

Solution explanation

Inserting at the front is O(1) - no traversal needed.

Show solution

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

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

struct Node *push_front(struct Node *head, int value) {
    struct Node *node = malloc(sizeof(struct Node));
    node->value = value;
    node->next = head;
    return node;
}

int main() {
    int n, x, length = 0;
    struct Node *head = NULL;
    scanf("%d", &n);
    for (int i = 0; i < n; i++) {
        scanf("%d", &x);
        head = push_front(head, x);
    }
    for (struct Node *p = head; p != NULL; p = p->next) {
        printf("%d ", p->value);
        length++;
    }
    printf("\n%d\n", length);
    return 0;
}

Output

Answer