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I was trying to solve This Problem on Spoj.
The problem is to find the sum of all divisors of i where i=1 to i=N.
We have to solve this in sqrt(n) complexity.
This is the Ac'ed python Code, I couldn't figure out the logic behind this.
Please provide me with some hints..Thanks
Let
.
For each x = 1..m we can find count of numbers divisible by x. It's
For each k = 1..m - 1 we can find all numbers x that divide exactly k numbers. It's range