GCD & LCM Coding Problems

Please refer Greatest Common Divisor (GCD) and Least Common Multiple (LCM) to know the background of these topics.

Easy Problems on GCD and LCM:

• Program to find GCD or HCF of two numbers
• Program to find LCM of two numbers
• Least Common Denominator (LCD)
• GCD of digits of a given number
• GCD of array
• LCM of array
• Find LCM of rational numbers
• GCD of two numbers when one of them can be very large
• GCD of elements in a given range
• LCM of First n Natural Numbers
• LCM of digits of a given number
• Program to find HCF iteratively
• GCD, LCM and Distributive Property

Medium Problems on GCD and LCM:

• Basic and Extended Euclidean algorithms
• Program to find GCD of floating point numbers
• HCF of array of fractions (or rational numbers)
• Pair with maximum GCD from two arrays
• LCM of factorial and its neighbors
• Largest subarray with GCD one
• Replace every matrix element with maximum of GCD of row or column
• Check if LCM of array elements is divisible by a prime number or not
• Print the kth common factor of two numbers
• Finding LCM of more than two (or array) numbers without using GCD
• Given GCD G and LCM L, find number of possible pairs (a, b)
• GCD of two numbers formed by n repeating x and y times
• Largest Subset with GCD 1
• Count pairs of natural numbers with GCD equal to given number

Hard Problems on GCD and LCM:

• Stein’s Algorithm for finding GCD
• Largest subsequence having GCD greater than 1
• Count number of pairs (A <= N, B <= N) such that gcd (A , B) is B
• Smallest number divisible by n and has at-least k trailing zeros
• Array with GCD of any of its subset belongs to the given array
• Find pair with maximum GCD in an array
• First N natural can be divided into two sets with given difference and co-prime sums
• Series with largest GCD and sum equals to n
• Maximum sum of distinct numbers with LCM as N
• Queries for GCD of all numbers of an array except elements in a given range
• Summation of GCD of all the pairs up to N
• Count number of subsets of a set with GCD equal to a given number
• Check if elements of array can be made equal by multiplying given prime numbers

Quick Links:

• Recent articles on GCD and LCM
• Practice problems on Math