LinkedList Concatenation

Algorithm

INPUT: HEADER AND HEADER1 ARE POINTER TO THE HEADER NODE OF THE LINKEDLISTS
OUTPUT: CONCATENATED LINKEDLIST
DATA STRUCTURE: SINGLY LINKEDLIST

STEP 1: START
STEP 2: PTR=HEADER->LINK
STEP 3: WHILE(PTR->LINK!=NULL)
STEP 4: PTR=PTR->LINK
STEP 5: ENDWHILE
STEP 6: PTR->LINK=HEADER1->LINK 
STEP 7: END

Code

 #include <stdio.h>
 #include <stdlib.h>
 int getnode(int);
 void display();
 int concat();
 int x, pos, n;
 struct node
 {
    int data;
    struct node *link;
 };
 struct node *prev, *head, *news, *p, *ptr;
 struct node *q1;
 struct node *header, *header1;
 struct node *q, *r, *s;
 int main()
 {
    printf("ENTER THE LIMIT OF LINKERLIST 1");
    scanf("%d", &n);
    getnode(n);
    header1=header;
    printf("ENTER THE LIMIT OF LINKEDLIST 2 ");
    scanf("%d", &n);
    getnode(n);
    concat();
    printf("THE CONCATENATED LIST IS:");
    display(header1);
    return 0;
 }
 void display(struct node *head1)
 {
    struct node *ptr;
    ptr = head1->link;
    // ptr=header->link;
    while (ptr != NULL)
    {
        printf("%d ", ptr->data);
        ptr = ptr->link;
    }
 }
 concat()
 {
    q=header1->link;
    while(q!=NULL)
    {
        q1=q;
        // printf(" %d",q->data);
        q=q->link;
    }
    q1->link=header->link;
    
    // q->link=header1;
 }
 int getnode(int n)
 {
    header = malloc(sizeof(struct node));
    head = NULL;
    for (int i = 0; i < n; i++)
    {
        p = malloc(sizeof(struct node));
        q1 = malloc(sizeof(struct node));
        q = NULL;
        scanf("%d", &p->data);
        p->link = NULL;
        if (head == NULL)
            head = p;
        else
            prev->link = p;
        prev = p;
    }
    header->link = head;
    display(header);
    return 0;
 }

Output

user@computer$ : ENTER THE LIMIT OF LINKERLIST 15
 1
 2
 3
 4
 5
 1 2 3 4 5 ENTER THE LIMIT OF LINKEDLIST 2 5
 6
 7
 8 
3
 5
 6 7 8 3 5 THE CONCATENATED LIST IS:1 2 3 4 5 6 7 8 3 5