# Linked List Intersection - Amazon Top Interview Questions

### Problem Statement :

```Given two sorted linked lists l0, and l1, return a new sorted linked list containing the intersection of the two lists.

Constraints

n ≤ 100,000 where n is the number of nodes in l0

m ≤ 100,000 where m is the number of nodes in l1

Example 1

Input

l0 = [1, 3, 7]

l1 = [2, 3, 7, 9]

Output

[3, 7]

Example 2

Input

l0 = [1, 2, 3]

l1 = [4, 5, 6]

Output

None```

### Solution :

```                        ```Solution in C++ :

LLNode* solve(LLNode* l0, LLNode* l1) {
if (l0 == NULL or l1 == NULL) return NULL;

LLNode *curr = NULL, *head = NULL;
LLNode* ptr1 = l0;
LLNode* ptr2 = l1;

while (ptr2 and ptr1) {
if (ptr2->val == ptr1->val) {
LLNode* newnode = new LLNode(ptr1->val);
curr = newnode;
} else {
curr->next = newnode;
curr = curr->next;
}

ptr1 = ptr1->next;
ptr2 = ptr2->next;
}

else {
if (ptr1->val > ptr2->val)
ptr2 = ptr2->next;
else
ptr1 = ptr1->next;
}
}

}```
```

```                        ```Solution in Java :

import java.util.*;

class Solution {
public LLNode solve(LLNode l0, LLNode l1) {

while (l0 != null && l1 != null) {
if (l0.val == l1.val) {
tail.next = l0;
tail = tail.next;

l0 = l0.next;
l1 = l1.next;
} else if (l0.val > l1.val)
l1 = l1.next;
else
l0 = l0.next;
}

tail.next = null;

}
}```
```

```                        ```Solution in Python :

class Solution:
def solve(self, l0, l1):
# Remember the lists are sorted
# Also remember that intersection of two linked lists does not mean the lists actually intersect
# like the case where l0 : 3--4---
#                                 |
#                      l1   1--2--5--6--7
# like l1 is not a part of l0 or vice versa
# This is just plain intersection where we have to find elements that are common in both.
while l0 is not None and l1 is not None:
if l0.val == l1.val:
else:
tail.next = LLNode(l0.val)
tail = tail.next
l0, l1 = l0.next, l1.next
elif l0.val < l1.val:
l0 = l0.next
elif l1.val < l0.val:
l1 = l1.next
```

## Left Rotation

A left rotation operation on an array of size n shifts each of the array's elements 1 unit to the left. Given an integer, d, rotate the array that many steps left and return the result. Example: d=2 arr=[1,2,3,4,5] After 2 rotations, arr'=[3,4,5,1,2]. Function Description: Complete the rotateLeft function in the editor below. rotateLeft has the following parameters: 1. int d

## Sparse Arrays

There is a collection of input strings and a collection of query strings. For each query string, determine how many times it occurs in the list of input strings. Return an array of the results. Example: strings=['ab', 'ab', 'abc'] queries=['ab', 'abc', 'bc'] There are instances of 'ab', 1 of 'abc' and 0 of 'bc'. For each query, add an element to the return array, results=[2,1,0]. Fun

## Array Manipulation

Starting with a 1-indexed array of zeros and a list of operations, for each operation add a value to each of the array element between two given indices, inclusive. Once all operations have been performed, return the maximum value in the array. Example: n=10 queries=[[1,5,3], [4,8,7], [6,9,1]] Queries are interpreted as follows: a b k 1 5 3 4 8 7 6 9 1 Add the valu

## Print the Elements of a Linked List

This is an to practice traversing a linked list. Given a pointer to the head node of a linked list, print each node's data element, one per line. If the head pointer is null (indicating the list is empty), there is nothing to print. Function Description: Complete the printLinkedList function in the editor below. printLinkedList has the following parameter(s): 1.SinglyLinkedListNode

## Insert a Node at the Tail of a Linked List

You are given the pointer to the head node of a linked list and an integer to add to the list. Create a new node with the given integer. Insert this node at the tail of the linked list and return the head node of the linked list formed after inserting this new node. The given head pointer may be null, meaning that the initial list is empty. Input Format: You have to complete the SinglyLink