GATE 2025 CS (CS1) – Question 62

Let LIST be a datatype for an implementation of linked list defined as follows:

typedef struct list {
    int data;
    struct list *next;
} LIST;

Suppose a program has created two linked lists, L1 and L2, whose contents are given below (code for creating L1 and L2 is not provided here). L1 contains 9 nodes, and L2 contains 7 nodes.
L1: 1 -> 7 -> 12 -> 3 -> 9 -> 5 -> 11 -> 15 -> 8
L2: 1 -> 11 -> 6 -> 9 -> 15 -> 12 -> 4

Consider the following C program segment that modifies the list L1. The number of nodes that will be there in L1 after the execution of the code segment is ________ . (Answer in integer)

int find (int query, LIST *list) {
    while (list != NULL){
        if(list->data == query) return 1;
        list = list->next;
    }
    return 0;
}
int main () {
    ...
    ptr1=L1; ptr2=L2;
    while (ptr1->next != NULL){
        query = ptr1->next->data;
        if (find (query, L2))
            ptr1->next = ptr1->next->next;
        else ptr1 = ptr1->next;
    }
    ...
    return 0;
}