## Finding the Longest Consecutive Sequence in an Array

Problem Statement We have to implement the longestConsecutive function that takes an integer array as input and returns the length of the longest sequence of consecutive integers. For example, in array [4, 2, 7, 8, 1, 5, 6, 0] we have two sequences of consecutive integers: [0, 1, 2] and [4, 5, 6, 7, 8]. The longest sequence ([4, 5, 6, 7, 8]) has length 5. Brute Force Solution It would be easier to find consecutive sequences if the input array is sorted....

November 9, 2023 · 5 min · Avnish

## Checking the Validity of a Sudoku Grid

Problem Statement We have to implement an isValidSudoku function that takes a 9x9 matrix (representing a Sudoku grid) as input and returns true if the grid is valid and false otherwise. Sudoku Grid A Sudoku grid is valid if Every row contains digits from 1 to 9 without repetition. Rows in a Sudoku Grid Every column contains digits from 1 to 9 without repetition. Columns in a Sudoku Grid...

November 2, 2023 · 10 min · Avnish

## Finding Most Frequent Elements in an Array

Problem Statement We have to implement a topKFrequent function that takes an integer array and a value k as input and returns the k most frequent elements in the input array. For example, topKFrequent({1, 1, 2, 2, 3, 5, 2}, 2) will return the top 2 most frequent elements in the array i.e. {2, 1}. If multiple elements have the same frequency, then any of them could be returned in the solution as long as its length is k....

October 26, 2023 · 6 min · Avnish

## Group Anagrams in an Array

Problem Statement We have to implement a groupAnagram function that takes an array of strings as input and returns a new array with anagrams grouped. The input string array is assumed to be composed entirely of lowercase English characters. Brute Force Solution If two strings are anagrams then their sorted order will be the same. Thus, anagrams could be grouped under their sorted order. The brute-force implementation of groupAnagram uses a hashmap for grouping....

October 22, 2023 · 7 min · Avnish

## Finding Elements in an Array that Sum Up to a Target Value

Problem Statement We have to implement a twoSums() function that takes an integer array and a target value as inputs. It returns the indexes of two elements in the input array which could be summed up to the target value. It is assumed that the input array contains only one valid pair of elements that sum up to the target value. Brute Force Solution The brute-force solution will find the sum of all element pairs in the array using nested loops....

October 15, 2023 · 4 min · Avnish