Hashing Data Structure
Learn more about Hashing in DSA Self Paced Course
Practice Problems on Hashing
What is Hashing?
Hashing is a technique or process of mapping keys, and values into the hash table by using a hash function. It is done for faster access to elements. The efficiency of mapping depends on the efficiency of the hash function used.
Let a hash function H(x) maps the value x at the index x%10 in an Array. For example if the list of values is [11,12,13,14,15] it will be stored at positions {1,2,3,4,5} in the array or Hash table respectively.
Hashing Data Structure
Topics:
- Easy:
- Find whether an array is subset of another array
- Union and Intersection of two linked lists
- Given an array A[] and a number x, check for pair in A[] with sum as x
- Maximum distance between two occurrences of same element in array
- Count maximum points on same line
- Most frequent element in an array
- Find the only repetitive element between 1 to n-1
- How to check if two given sets are disjoint?
- Non-overlapping sum of two sets
- Check if two arrays are equal or not
- Find missing elements of a range
- Minimum number of subsets with distinct elements
- Remove minimum number of elements such that no common element exist in both array
- Find pairs with given sum such that elements of pair are in different rows
- Count pairs with given sum
- Count quadruples from four sorted arrays whose sum is equal to a given value x
- Sort elements by frequency
- Find all pairs (a, b) in an array such that a % b = k
- Group words with same set of characters
- k-th distinct (or non-repeating) element in an array.
- Medium:
- Find Itinerary from a given list of tickets
- Find number of Employees Under every Employee
- Longest subarray with sum divisible by k
- Find the largest subarray with 0 sum
- Longest Increasing consecutive subsequence
- Count distinct elements in every window of size k
- Design a data structure that supports insert, delete, search and getRandom in constant time
- Find subarray with given sum | Set 2 (Handles Negative Numbers)
- Implementing our Own Hash Table with Separate Chaining in Java
- Implementing own Hash Table with Open Addressing Linear Probing in C++
- Minimum insertions to form a palindrome with permutations allowed
- Maximum possible difference of two subsets of an array
- Sorting using trivial hash function
- Smallest subarray with k distinct numbers
- Hard:
- Clone a Binary Tree with Random Pointers
- Largest subarray with equal number of 0s and 1s
- All unique triplets that sum up to a given value
- Palindrome Substring Queries
- Range Queries for Frequencies of array elements
- Elements to be added so that all elements of a range are present in array
- Cuckoo Hashing – Worst case O(1) Lookup!
- Count subarrays having total distinct elements same as original array
- Maximum array from two given arrays keeping order same
- Find Sum of all unique sub-array sum for a given array.
- Recaman’s sequence
- Length of longest strict bitonic subsequence
- Find All Duplicate Subtrees
- Find if there is a rectangle in binary matrix with corners as 1
- ‘Practice Problems’ on Hashing
- Top 20 Hashing Technique based Interview Questions
- ‘Quizzes’ on Hashing
- ‘Videos’ on Hashing
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