Yan Cui
I help clients go faster for less using serverless technologies.
Problem
An irrational decimal fraction is created by concatenating the positive integers:
0.123456789101112131415161718192021…
It can be seen that the 12th digit of the fractional part is 1.
If dn represents the nth digit of the fractional part, find the value of the following expression.
d1 x d10 x d100 x d1000 x d10000 x d100000 x d1000000
Solution
A pretty straight forward solution, the only trick is to turn the sequence of natural numbers 1, 2, 3, … 11, 12, 13.. into a continuous sequence of individual numbers. I did so by taking each number and turning it into a string array of its digits (e.g. 11 –> {"1"; "1"}) and concatenating these arrays using Seq.collect.
Whenever you’re ready, here are 3 ways I can help you:
- Production-Ready Serverless: Join 20+ AWS Heroes & Community Builders and 1000+ other students in levelling up your serverless game. This is your one-stop shop for quickly levelling up your serverless skills.
- I help clients launch product ideas, improve their development processes and upskill their teams. If you’d like to work together, then let’s get in touch.
- Join my community on Discord, ask questions, and join the discussion on all things AWS and Serverless.
Pingback: Project Euler 40: Find the nth digit of an irrational number | mathblog.dk