*1.7K*

Question:Write a program to check if 2 linked lists are identical?

#### Method 1(Iterative):-

To Determine if both Linked lists are identical, we need to traverse both lists simultaneously, and while traversing we need to compare data of each node.

**Implementation**

//returns 1 if both lists are identical or returns 0 int areIdenticalLinkedList(struct node * list1, struct node * list2) { while(1) { // return 1 if both are NULL if(list1 == NULL && list2 == NULL) return 1; // return 0 if one of them is NULL if(list1 == NULL || list2 == NULL) return 0; if(list1 -> data != list2 -> data) return 0; list1 = list1 -> next; list2 = list2 -> next; } }

#### Method2( Recursive):-

//returns 1 if both lists are identical or returns 0 int areIdenticalLinkedListRecursive(struct node * list1, struct node * list2) { // return 1 if both are same if (list1 == NULL && list2 == NULL) return 1; // return 0 if one of them is different if (list1 == NULL || list2 == NULL) return 0; if (list1 -> data != list2 -> data) return 0; // the recursive call return areIdenticalLinkedListRecursive(list1 -> next, list2 -> next); }

It may seem that both recursive and iterative implementation are the same but the iterative version is recommended since it offers better control and the recursive implementation maintains a stack of all the callbacks.