I heard that it is possible to compute $$$\sum\limits_{i=1}^n\frac{1}{i}\pmod{998244353}$$$ in $$$O(\sqrt n)$$$ complexity with some polynomial technology .
But I don't know how. Can someone give a solution ?
Need help in Harmonic series
I heard that it is possible to compute $$$\sum\limits_{i=1}^n\frac{1}{i}\pmod{998244353}$$$ in $$$O(\sqrt n)$$$ complexity with some polynomial technology .
But I don't know how. Can someone give a solution ?