Find the Intersection of Two Linked Lists

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In this tutorial, i am going to explain how to find the intersection of two linked lists. 

Given the heads of two singly linked lists. We have to write a code to find the intersection point of two linked lists. If no intersection point is found then return null.

You may assume there are no cycles anywhere in the entire linked structure. We have to solve this problem in O(n) time complexity and by using O(1) space.

For example:

Linked list 1:  4 -> 6 -> 2 -> 7 -> NULL

Linked list 2: 8 -> 2-> 7 -> NULL

In this example, the intersection point of two lists is at node 2.

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Find Longest Common Prefix in an Array of Strings

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How to find longest common prefix in an array of strings.

Given an array of strings, write a method to find the longest common prefix string. If no common prefix is found, return an empty string ” “.

For example:

Example 1:

Input: [“cat”,”cable”,”camera”]
Output: “ca”

The longest common prefix is ca.

Example 2:

Input: [“rat”,”dog”,”elephant”]
Output: “”

No common prefix is found.

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Detect Loop in Linked List

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How to detect loop in linked list.

Given a linked list, determine if it has a cycle or loop in it.

For example:

In the below example, the last node (whose value is 9) points to node whose value is 5. The last node of a linked list does not points to a null. It has a cycle.

Detect a loop in a linked list

Detect loop in a linked list

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