### haribhatt34's blog

By haribhatt34, history, 15 months ago, , I am having trouble understanding this question. Sorry the images are not quite clear, it's a snapshot from the PC. This question was asked previous year by a company which came to our college for recruitment.

The input example given are more like the multiple of 5. But I think there is more the question I am missing.

Thanks

UPDATE Don't know why images are not getting uploaded. Image 1, part 1 Image 1, part 2 Comments (5)
 » Auto comment: topic has been updated by haribhatt34 (previous revision, new revision, compare).
 » Auto comment: topic has been updated by haribhatt34 (previous revision, new revision, compare).
 » 15 months ago, # | ← Rev. 10 →   Note that F(X) is the power of 5 in the prime number factorization of X. In the given example, 250 = 21.53 is the prime number factorization of 250. Therefore, F(250) = 3. If X is not divisible by 5, then F(X) = 0. Let p be the largest integer such that .Then, the answer to the query N is 5p. S(p) can be computed iteratively as S(p) = S(p - 1) + F(5p), where p ≥ 1, and the base case is S(0) = 0. Finally, the sequence S(0), S(1), S(2), ... is strictly increasing, as it is guaranteed that F(5p) ≥ 1. Therefore, the sequence can be stored in an int array or a vector C++ object when the maximum value of N is known, and the standard library function lower_bound() can be used to find the answer to each query using binary search.
•  » » Thanks a lot man, for the explanation.
•  » » » With pleasure 