### Loser_'s blog

By Loser_, history, 3 months ago, hello I am stuck in this problem Digit Queries.I think I need to use recursion here although not quite sure how? Which algo or technique I need to study to solve this problem? Also please share similar types of problems from other ojs.Please help me with that. cses, Comments (9)
 » simple constructive algorithms is enough to solve this
 » 3 months ago, # | ← Rev. 3 →   This string contains numbers, numbers contain digits.Note: summary length of all n-digit numbers is easy to calculate. more detailed solutionSo you firstly brute force the length(L) of number, where your digit took place. Also this sum grows fast, so L < 18, so L-digit number fits in 64-bit numbers.Then you have position of first L-digit number. Now it's easy to find in what L-digit number your digit is.Then you have L-digit number and position of digit, you just output this digit of L-digit number.
•  » » 2 months ago, # ^ | ← Rev. 2 →   Thanks
 » 7 weeks ago, # | ← Rev. 2 →   Hello, I try to solve this problem https://cses.fi/problemset/task/2431/ I come up with a formuler: x is length of number (1,2,3,4) k = 9*1 + 90*2 + 900*3 + 9000*4 +..+9*(10^x)*x : total number here my code: https://cses.fi/paste/f1e04f128ac4fe471ae4e1/ however, my code passed only two first test cases. I don't know what wrong with my code. Here are test cases' resultPlease help me to point what's wrong. thank you.
 » 7 weeks ago, # | ← Rev. 2 →   this problem is same as Digits Sequence
•  » » thank you
•  » » I've submitted the same code as on cses.fi and it worked!. I don't know why it fails on cses.https://codeforces.com/contest/1177/submission/108590612
 » Good Constructive Algorithm question! Here is my descriptive solution (https://ideone.com/4yYbq4)
•  » » Thank you!