Question

I am trying to print the linked list using C.But it is printing me empty when I execute my ./a.out. Can someone help me out where I am doing wrong.Thanks.

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

struct node
{
        int data;
        struct node *next;
};

int main()
{
        node *start,*temp;
        start = (node *)malloc(sizeof(node));
        temp = start;
        temp -> next = NULL;
        while(1)
        {
                int query;
                printf("1.Insert\n");
                printf("2.Print\n");
                printf("Enter your choice:\n");
                scanf("%d",&query);
                if(query==1)
                {
                        int data;
                        printf("Enter the element to be inserted.\n");
                        scanf("%d",&data);
                        while(start->next!=NULL)
                        {
                                start = start -> next;
                        }
                        start->next = (node *)malloc(sizeof(node));
                        start = start->next;
                        start->data = data;
                        start->next = NULL;
                }
                else if(query ==2)
                {
                        printf("The list is as below:\n");
                        while(start->next!=NULL)
                        {
                                printf("%d \t",start->next->data);
                                start=start->next;

                        }
                }
                else
                break;
        }

        return 0;
}

Answer 1

Whenever you insert an element, you move start pointer to the one before NULL. Thus, whenever you want to print the list, start->next is NULL, and nothing could be printed.

You should use temp instead for both element insertion and list output. Just remember to point temp back to start before walking through the list.