Question

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

Suppose a program has created two linked lists, L1 and L2, whose contents are given in the figure below (code for creating L1 and L2 is not provided here). L1 contains 9 nodes, and L2 contains 7 nodes. 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:


 

Hint:

When working with linked lists in C, carefully track how nodes are added or removed by considering conditions and traversals through the list.

Answer 1

The program iterates through the linked list L1 and checks for the presence of each element from L1 in L2 using the function find(). If an element from L1 is found in L2, the corresponding node in L1 is removed. The find() function returns 1 when a match is found, and 0 otherwise.

In the given lists:
- L1: 1 → 7 → 12 → 3 → 9 → 5 → 11 → 15 → 8
- L2: 11 → 6 → 9 → 15 → 12 → 4

The values 11, 9, 12, and 15 are found in L2, and their corresponding nodes are removed from L1.

After the removal process, the remaining nodes in L1 will be:
1 → 7 → 3 → 5 → 8

Thus, the number of nodes left in L1 is 5.