Given parameters $a, b, c$; $max(a,b,c) <=\le 9000$. Your task is to compute $\sum\limits_{x = 1}^{a} \sum\limits_{y = 1}^{b} \sum\limits_{z = 1}^{c} d(xyz) $ where $ d(n)$ is the divisor count function : the number of positive divisors of $n$.↵
↵
This is the final problem in my recent OI Mocktest, I can only solve it to the first subtask : $max(a,b,c)<=\le 200$, by iterating over all triplets $(x,y,z)$ and adding $d(xyz)$ to the result variable, to compute $d(xyz)$, I used applied prime sieve.↵
↵
Can you suggest the algorithm for the final subtask?
↵
This is the final problem in my recent OI Mocktest, I can only solve it to the first subtask : $max(a,b,c)
↵
Can you suggest the algorithm for the final subtask?
