We can also use hashing to avoid building a graph. The idea is to first find the starting point. A starting point would never be on ‘to’ side of a ticket.

# Category - Hashing

Given an unsorted array that may contain duplicates. Also given a number k which is smaller than size of array. Write a function that returns true

Time Complexity: Depends on what sorting algorithm we use. If we use Merge Sort or Heap Sort then (-)(nlogn) in worst case.

Time Complexity: Depends on what sorting algorithm we use. If we use Merge Sort or Heap Sort then (-)(nlogn) in worst case.

Time Complexity: Depends on what sorting algorithm we use. If we use Merge Sort or Heap Sort then (-)(nlogn) in worst case.

Given two Linked Lists, create union and intersection lists that contain union and intersection of the elements present in the given lists.

Given two Linked Lists, create union and intersection lists that contain union and intersection of the elements present in the given lists.

An efficient solution based on hash map is discussed. We need to check the Horizontal Distances from root for all nodes and two nodes have the same

Given two Linked Lists, create union and intersection lists that contain union and intersection of the elements present in the given lists.

Given two arrays: arr1[0..m-1] and arr2[0..n-1]. Find whether arr2[] is a subset of arr1[] or not. Both the arrays are not in sorted order.