display a sorted linked list with every new element in c

Question

So I am trying to make a program in c that will let the user enter numbers until the number 0 in entered. Then create a linked list that will sort the entered integers from smallest to largest. Here is my code:

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

typedef struct node{
    int data;
    struct node *ptr;
} node;

node* insert(node* head, int num) {
    node *temp, *prev, *next;
    temp = (node*)malloc(sizeof(node));
    temp->data = num;
    temp->ptr = NULL;
    if(!head){
        head=temp;
    } else{
        prev = NULL;
        next = head;
        while(next && next->data<=num){
            prev = next;
            next = next->ptr;
        }
        if(!next){
            prev->ptr = temp;
        } else{
            if(prev) {
                temp->ptr = prev->ptr;
                prev-> ptr = temp;
            } else {
                temp->ptr = head;
                head = temp;
            }
        }
    }
    return head;
}

void free_list(node *head) {
    node *prev = head;
    node *cur = head;
    while(cur) {
        prev = cur;
        cur = prev->ptr;
        free(prev);
    }
}

int main(){
    int num;
    node *head, *p;
    head = NULL;

    do {
        printf("Enter a number: ");
        scanf("%d",&num);
        printf("%d->\n", num);
        if(num) {
            head = insert(head, num);
        }
    } while(num);

    p = head;
    printf("\nThe entered numbers are:\n");

    while(p) {
        printf("%d->", p->data);
        p = p->ptr;
    }
    free_list(head);
    printf("NULL");

    return 0;
}

As you can hopefully will see, the output will look something like this:

Enter number: 6
6->NULL
Enter number: 3
3->NULL
Enter number: 9
9->NULL
Enter number: 0
0->

The entered numbers are :
3->6->9->NULL

However, what I want is these numbers to be sorted as they are being entered and inserted into the list (also I need the 0 to not be displayed). So the output should look like this:

Enter number: 6
6->NULL
Enter number: 3
3->6->NULL
Enter number: 9
3->6->9->NULL
Enter number: 0

The entered numbers are :
3->6->9->NULL

Can somebody help me with this please???

Answer 1

I do not see how you get this output

Enter number: 6
6->NULL
Enter number: 3
3->NULL
Enter number: 9
9->NULL
Enter number: 0
0->

Within this do-while loop

do {
    printf("Enter a number: ");
    scanf("%d",&num);
    printf("%d->\n", num);
    if(num) {
        head = insert(head, num);
    }
} while(num);

the only statement that outputs something is

    printf("%d->\n", num);

but it does not output the string ->NULL.

Within the function insert there is no output statement.

To get the desired output in the do while statement you need to write

do {
    printf("Enter a number: ");
    scanf("%d",&num);
    if(num) {
        head = insert(head, num);
        for ( p = head; p != NULL; p = p->ptr )
        {
            printf("%d->", p->data);
        }
        puts( "NULL " );   
    }
} while(num);

Also your function insert is too complicated. There are too many if statements and local variables. The function can be written simpler. For example

node * insert( node *head, int num ) 
{
    node *temp = malloc( sizeof( node ) );
    temp->data = num;

    if ( head == NULL || head->data < num )
    {
        temp->ptr = head;
        head = temp;
    }
    else
    {
        node *current = head;
        while ( ( current->ptr != NULL ) && 
                !( num < current->ptr->data ) )
        {
            current = current->ptr;
        }
        
        temp-ptr = current->ptr;
        current->ptr = temp;
    }

    return head;
}