**Statement**: Given a vector of ranges of the form [L,R] (L,R > 0). We have to print all unique integers that can be formed by concatenating integers taking one at a time from each of such ranges.

**Constraints**: Size of vector of ranges ~ 100

R - L <= 1000

**Sample Example**: Given vector: <[2,4], [3,5]>

**Output**: 23,24,25,33,34,35,43,44,45

This was one of the question that I was asked in an interview. I could only give a recursion based approach to this, where I checked for every integer in every range. Can someone help me with a more optimised approach for this

In your first statement, you are talking about integers while, in the end, it says "digits". Which one is correct?

Thanks, corrected the statement

Auto comment: topic has been updated by KevinDeBruyne17 (previous revision, new revision, compare).Is this problem really solvable? A valid input is {[100, 999], [100, 999], ..., [100, 999]} for 100 intervals which has an absurd number of answers that can't be printed in any reasonable amount of time.