Given two integers K and N, the task is to find the count of integers from the range [2, N – 1] whose sum of prime divisors is K
Input: N = 20, K = 7
7 and 10 are the only valid numbers.
sumPFactors(7) = 7
sumPFactors(10) = 2 + 5 = 7
Input: N = 25, K = 5
Approach: Create an array sumPF where sumPF[i] stores the sum of prime divisors of i which can be easily calculated using the approach used in this article. Now, initialise a variable count = 0 and run a loop from 2 to N – 1 and for every element i if sumPF[i] = K then increment the count.
Below is the implementation of the above approach:
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