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euler-totient

29 posts

Sum of GCD of all numbers upto N with N itself

Last Updated: 15 July 2025

Given an integer N, the task is to find the sum of Greatest Common Divisors of all numbers up to N with N itself.Examples:Input: N = 12Output: 40Explanation:GCD of [1, 12]...read more

Count of elements having Euler's Totient value one less than itself

Last Updated: 15 July 2025

Given an array arr[] of N integers, and a range L to R, the task is to find the total number of elements in the array from index L to R that satisfies the following condit...read more

Dynamic Programming

Probability of Euler's Totient Function in a range [L, R] to be divisible by M

Last Updated: 15 July 2025

Given three integers L, R, and M, the task is to find the probability of Euler's Totient Function of a number in the range [L, R] is divisible by M.Euler’s Totient functio...read more

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Count of integers up to N which are non divisors and non coprime with N

Last Updated: 15 July 2025

Given an integer N, the task is to find the count of all possible integers less than N satisfying the following properties:The number is not coprime with N i.e their GCD i...read more

Count of Distinct strings possible by inserting K characters in the original string

Last Updated: 15 July 2025

Given a string S and an integer K, the task is to find the total number of strings that can be formed by inserting exactly K characters at any position of the string S. Si...read more

Modular Arithmetic

Permutation and Combination

Check if Euler Totient Function is same for a given number and twice of that number

Last Updated: 15 July 2025

Given an integer N, the task is to check whether the Euler’s Totient Function of N and 2 * N are the same or not. If they are found to be the same, then print “Yes”. Other...read more

Pattern Searching

Count all possible values of K less than Y such that GCD(X, Y) = GCD(X+K, Y)

Last Updated: 14 April 2021

Given two integers X and Y, the task is to find the number of integers, K, such that gcd(X, Y) is equal to gcd(X+K, Y), where 0 K Y.Examples:Input: X = 3, Y = 15Output: 4...read more

Technical Scripter

Technical Scripter 2020

Generate an array having sum of Euler Totient Function of all elements equal to N

Last Updated: 17 January 2022

Given a positive integer N, the task is to generate an array such that the sum of the Euler Totient Function of each element is equal to N.Examples:Input: N = 6Output: 1 6...read more

Technical Scripter 2020

Count of numbers up to N having at least one prime factor common with N

Last Updated: 20 July 2022

Given an integer N, the task is to count the number of integers from the range [1, N] having at least one in common prime factor with N other than 1.Examples:Input: N = 5O...read more

Natural Numbers

Count number of pairs (i, j) up to N that can be made equal on multiplying with a pair from the range [1, N / 2]

Last Updated: 20 July 2022

Given a positive even integer N, the task is to find the number of pairs (i, j) from the range [1, N] such that the product of i and L1 is the same as the product of j and...read more

Count of non co-prime pairs from the range [1, arr[i]] for every array element

Last Updated: 10 November 2021

Given an array arr[] consisting of N integers, the task for every ith element of the array is to find the number of non co-prime pairs from the range [1, arr[i]].Examples:...read more

Sum of Euler Totient Functions obtained for each divisor of N

Last Updated: 28 May 2021

Given a positive integer N, the task is to find the sum of the Euler Totient Function for all the divisor of the given number N.Examples:Input: N = 3Output: 3Explanation:D...read more

Count numbers up to N whose GCD with N is less than that number

Last Updated: 01 February 2023

Given an integer N, the task is to count the values of K ( where 1 ? K? N ), such that 1 GCD(K, N) K.Examples:Input: N = 10Output: 3Explanation: The values of K which sat...read more

Euler Totient for Competitive Programming

Last Updated: 12 March 2024

What is Euler Totient function(ETF)?Euler Totient Function or Phi-function for 'n', gives the count of integers in range '1' to 'n' that are co-prime to 'n'. It is denote...read more

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Euler Totient Function in Python

Last Updated: 24 April 2024

Euler’s Totient function, also known as Euler's Phi Function Φ (n) is a mathematical function that counts the number of positive integers up to a given integer n that are ...read more

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