Given a number N which is prime. The task is to find all the numbers less than or equal to 10^6 whose minimum prime factor is N.
Input: N = 2 Output: 500000 Input: N = 3 Output: 166667
Approach: Use sieve of Eratosthenes to find the solution of the problem. Store all the prime numbers less than 10^6 . Form another sieve which will store the count of all the numbers whose minimum prime factor is the index of the sieve. Then display the count of the prime number N (i.e. sieve_count[n]+1), where n is the prime number .
Below is the implementation of above approach:
Count = 500000 Count = 166667
Attention reader! Don’t stop learning now. Get hold of all the important DSA concepts with the DSA Self Paced Course at a student-friendly price and become industry ready.
- Sum of largest prime factor of each number less than equal to n
- Count of subarrays whose products don't have any repeating prime factor
- Count all prime numbers in a given range whose sum of digits is also prime
- Find largest factor of N such that N/F is less than K
- Numbers less than N which are product of exactly two distinct prime numbers
- Numbers with sum of digits equal to the sum of digits of its all prime factor
- Print all numbers whose set of prime factors is a subset of the set of the prime factors of X
- Sum of Semi-Prime Numbers less than or equal to N
- Count pairs with sum as a prime number and less than n
- Sum of Maximum and Minimum prime factor of every number in the Array
- Exactly n distinct prime factor numbers from a to b
- Least prime factor of numbers till n
- Count of distinct power of prime factor of N
- Count prime numbers that can be expressed as sum of consecutive prime numbers
- Nearest prime less than given number n
- Number less than equals to N with maximum product of prime factors
- First element of every K sets having consecutive elements with exactly K prime factors less than N
- Count numbers from range whose prime factors are only 2 and 3
- Sum of numbers in a range [L, R] whose count of divisors is prime
- Count numbers from range whose prime factors are only 2 and 3 using Arrays | Set 2
If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to firstname.lastname@example.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.
Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.