Frequency-counting - Basic Articles

Length of the longest subsequence consisting of distinct elements

Given an array arr[] of size N, the task is to find the length of the longest subsequence consisting of distinct elements only. Examples: Input:… Read More

cpp-set

frequency-counting

subsequence

Arrays

DSA

Hash

Check if all strings of an array can be made same by interchanging characters

Given an array arr[] of size N consisting of equal length strings, the task is to check if it is possible to make all strings… Read More

frequency-counting

DSA

Hash

Searching

Strings

Check if characters of a given string can be used to form any N equal strings

Given a string S and an integer N, the task is to check if it is possible to generate any string N times from the… Read More

frequency-counting

DSA

Greedy

Hash

School Programming

Searching

Strings

Maximize length of Subarray of 1’s after removal of a pair of consecutive Array elements

Given a binary array arr[] consisting of N elements, the task is to find the maximum possible length of a subarray of only 1’s, after… Read More

frequency-counting

subarray

Arrays

DSA

Greedy

Mathematical

Matrix

Searching

Count of subsequences consisting of the same element

Given an array A[] consisting of N integers, the task is to find the total number of subsequence which contain only one distinct number repeated… Read More

cpp-map

frequency-counting

subsequence

Arrays

DSA

Hash

Mathematical

Find ratio of zeroes, positive numbers and negative numbers in the Array

Given an array a of integers of size N integers, the task is to find the ratio of positive numbers, negative numbers and zeros in… Read More

cpp-array

frequency-counting

Java-Array-Programs

Arrays

DSA

School Programming

Check if given string contains all the digits

Given a string str consisting of alphanumeric characters, the task is to check whether the string contains all the digits from 1 to 9. The… Read More

frequency-counting

Arrays

DSA

Hash

Searching

Strings

Program to parse the Molecules and get the Atoms count

Given a chemical formula as a string, the task is to get the count of atoms in this chemical formula.Examples: Input: str = "Fe2H3OH" Output:… Read More

frequency-counting

Data Structures

DSA

Hash

Java

School Programming

Strings

Map every character of one string to another such that all occurrences are mapped to the same character

Given two strings s1 and s2, the task is to check if characters of the first string can be mapped with the character of the… Read More

frequency-counting

DSA

Strings

Find the first duplicate element in the linked list

Given a linked list. Find the first element from the left which appears more than once. If all the elements are unique then print -1.Examples:… Read More

frequency-counting

DSA

Linked List

Find the smallest positive number missing from an unsorted array : Hashing Implementation

Given an unsorted array with both positive and negative elements including 0. The task is to find the smallest positive number missing from the array… Read More

cpp-unordered_map

frequency-counting

Arrays

DSA

Heap

Count common characters in two strings

Given two strings s1 and s2 consisting of lowercase English alphabets, the task is to count all the pairs of indices (i, j) from the… Read More

frequency-counting

Algorithms

Competitive Programming

DSA

Searching

Strings

Count occurrences of a string that can be constructed from another given string

Given two strings str1 and str2 where str1 being the parent string. The task is to find out the number of string as str2 that… Read More

frequency-counting

DSA

Hash

Pattern Searching

Strings

Find the player who rearranges the characters to get a palindrome string first

Given an even length string S consisting of lower-case English alphabets only, we have two players playing the game. The rules are as follows: the… Read More

frequency-counting

palindrome

DSA

Strings

Count pairs from two arrays having sum equal to K

Given an integer K and two arrays A1 and A2, the task is to return the total number of pairs (one element from A1 and… Read More

cpp-unordered_map

frequency-counting

DSA

Mathematical

Searching

Array elements with prime frequencies

Given a string. The task is to find the count of characters whose number of occurrences is prime. Examples: Input : str = "geeksforgeeks" Output… Read More

cpp-unordered_map

frequency-counting

Prime Number

Arrays

DSA

Find array elements with frequencies in range [l , r]

Given an array of integers, find the elements from the array whose frequency lies in the range [l, r]. Examples: Input : arr[] = {… Read More

frequency-counting

Technical Scripter 2018

Arrays

DSA

Hash

Searching

Technical Scripter

Replace every elements in the array by its frequency in the array

Given an array of integers, replace every element by its frequency in the array. Examples: Input : arr[] = { 1, 2, 5, 2, 2,… Read More

cpp-unordered_map

frequency-counting

Technical Scripter 2018

Arrays

DSA

Hash

Technical Scripter

Remove elements from the array which appear more than k times

Given an array of integers, remove all the occurrences of those elements which appear strictly more than k times in the array.Examples: Input : arr[]… Read More

cpp-unordered_map

frequency-counting

Technical Scripter 2018

Arrays

Competitive Programming

DSA

Hash

Searching

Technical Scripter

Sum of all odd frequency elements in an array

Given an array of integers containing duplicate elements. The task is to find the sum of all odd occurring elements in the given array. That… Read More

cpp-unordered_map

frequency-counting

Arrays

DSA

Hash