LinkedList Merging

Algorithm

INPUT: HEADER1 AND HEADER2 ARE POINTER TO THE HEADER NODE OF THE LINKEDLISTS
OUTPUT: MERGED LINKEDLIST
DATA STRUCTURE: SINGLY LINKEDLIST

STEP 1: START
STEP 2: PTR1=HEADER1->LINK ,PTR2=HEADER2->LINK ,PTR3=HEADER3->LINK
STEP 3: WHILE(PTR1!=NULL&&PTR2!=NULL)
STEP 4: NEW=NEWNODE(NODE)
STEP 4: IF(PTR1->DATA<PTR2->DATA)
STEP 5: NEW->DATA=PTR1->DATA
STEP 6: NEW->LINK=NULL
STEP 7: PTR3->LINK=NEW
STEP 8: PTR3=NEW
STEP 9: PTR1=PTR1->LINK
STEP 10: ELSE IF(PTR1->DATA==PTR2->DATA)
STEP 11: NEW->DATA=PTR2->DATA
STEP 12: NEW->LINK=NULL;
STEP 13: PTR3->LINK=NEW
STEP 14: PTR3-NEW
STEP 15: PTR1=PTR1->LINK 
STEP 16: PTR2=PTR2->LINK
STEP 17: ELSE
STEP 18: NEW->DATA=PTR2->DATA
STEP 19: NEW->LINK=NULL
STEP 20: PTR3->LINK=NEW
STEP 21: PTR3=NEW
STEP 22: PTR2=PTR2->LINK
STEP 23: ENDWHILE
STEP 24: WHILE(PTR1!=NULL)
STEP 25: NEW->DATA=PTR1->DATA
STEP 26: NEW->LINK=NULL
STEP 27: PTR3->LINK=NEW
STEP 28: PTR3=NEW
STEP 29: PTR1=PTR1->LINK
STEP 30: ENDWHILE
STEP 31: WHILE(PTR2!=NULL)
STEP 32: NEW->DATA=PTR2->DATA
STEP 33: NEW->LINK=NULL
STEP 34: PTR3->LINK=NEW
STEP 35: PTR3=NEW
STEP 36: PTR2=PTR2->LINK
STEP 37: ENDWHILE
STEP 38: END

Code

 #include <stdio.h>
 #include <stdlib.h>
 int getnode(int);
 void display();
 void merge();
 void newnode();
 int x, pos, n;
 struct node
 {
    int data;
    struct node *link;
 };
 struct node *prev, *head, *news, *p, *ptr,*ptr1,*ptr2,*ptr3;
 struct node *q1;
 struct node *header, *header1,*header3,*header2;
 struct node *q, *r, *s;
 int main()
 {
    printf("ENTER THE LIMIT OF LINKEDLIST 1: ");
    scanf("%d", &n);
    getnode(n);
    header1=header;
    printf("ENTER THE LIMIT OF LINKEDLIST 2 ");
    scanf("%d", &n);
    getnode(n);
    header2=header;
    merge();
    printf("THE MERGE LIST IS:");
    display(header3);
    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;
    }
 }
 void newnode()
 {
    news=malloc(sizeof(struct node));
 }
 void merge()
 {   
    header3=malloc(sizeof(struct node));
    header3->link=news;
    ptr1=header1->link;
    ptr2=header2->link;
    ptr3=header3;
    while(ptr1!=NULL&&ptr2!=NULL)
    {
        if(ptr1->data<ptr2->data)
        {
            newnode();
            news->data=ptr1->data;
            news->link=NULL;
            ptr3->link=news;
            ptr3=news;
            ptr1=ptr1->link;
        }
        else if(ptr1->data==ptr2->data)
        {
             newnode();
            news->data=ptr2->data;
            news->link=NULL;
            ptr3->link=news;
            ptr3=news;
            ptr1=ptr1->link;
            ptr2=ptr2->link;
           
        }
        else{
             newnode();
            news->data=ptr2->data;
            news->link=NULL;
            ptr3->link=news;
            ptr3=news;
            ptr2=ptr2->link;
           
        }
        
       
    }
    while(ptr1!=NULL)
    {
        
        newnode();
        news->data=ptr1->data;
        news->link=NULL;
        ptr3->link=news;
        ptr3=news;
        ptr1=ptr1->link;
       
    }
    while(ptr2!=NULL)
    {
        newnode();
        news->data=ptr2->data;
        news->link=NULL;
        ptr3->link=news;
        ptr3=news;
        ptr2=ptr2->link;
    }
 }
 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 LINKEDLIST 1: 5
 1
 3
 5
 7
 9
 1 3 5 7 9 ENTER THE LIMIT OF LINKEDLIST 2 5
 2
 4
 6
 8
 10
 2 4 6 8 10 THE MERGE LIST IS:1 2 3 4 5 6 7 8 9 10