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
- Exactly n distinct prime factor numbers from a to b
- Least prime factor of numbers till n
- Count of subarrays whose products don't have any repeating prime factor
- Count all the numbers in a range with smallest factor as K
- Numbers with sum of digits equal to the sum of digits of its all prime factor
- Find count of Almost Prime numbers from 1 to N
- Prime Factor
- Minimum and Maximum prime numbers in an array
- Numbers in range [L, R] such that the count of their divisors is both even and prime
- Count common prime factors of two numbers
- Count numbers from range whose prime factors are only 2 and 3
- N-th prime factor of a given number
- k-th prime factor of a given number
- Pair of prime numbers with a given sum and minimum absolute difference
- Queries for the difference between the count of composite and prime numbers in a given range
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