Build a Linked List

Lab C Intermediate 20 points

Read n integers and append each to the end of a singly linked list. Print the list as 1 -> 2 -> 3 -> NULL and free every node.

Input

Line 1: n. Line 2: n integers.

Output

One line.

Example

Input

3
1 2 3

Output

1 -> 2 -> 3 -> NULL

Sample input available Sample output available

Editor

Hints

Keep a tail pointer so appending doesn't have to walk the whole list.

Save next before freeing a node.

Solution explanation

Each node holds a value and a pointer to the next node; NULL marks the end.

Show solution

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

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

int main() {
    int n, x;
    struct Node *head = NULL;
    struct Node *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 *p = head;
    while (p != NULL) {
        printf("%d -> ", p->value);
        p = p->next;
    }
    printf("NULL\n");
    while (head != NULL) {
        struct Node *next = head->next;
        free(head);
        head = next;
    }
    return 0;
}

Output

Answer