# FACTORIAL HELP

I have two questions …
Q1 . I’m new to programming i know all the syntax and everything but the problem comes in that I cannot understand the problem properly that is written until or unless someone properly tells me what the program is or show me an example of input and output that is required by the program exactly.

Q2. Can someone make me the understand what the FACTORIAL program asks me to do basically just explain me the program.

Hi,

I guess you are talking about FCTRL problem.

First of all you have to know what the factorial is, see the wikipedia if you don’t or ask if something is unclear On wikipedia page you can see, that factorial numbers are bigger and bigger. So the problem statement asks only how many zeros are at the end of i-th factorial number. Try to write some small factorial numbers by hand to find out when it ends with zero(s).

Hi,if u cannot understand the problem properly ,then:

(1)The best way to do is to read the problem statement as many times as you can, read it part-wise , try to note the parameters and other important points .

(2)Try to read the the queries and problem setter answers in the discussion forum on the question page.Because most of the time,the doubts/queries are common.

(3)Another best way is to try solving the easy problems (as the easy problems are even easier to understand) in the practice section,then gradually start practicing the difficult one.

Secondly the factorial problem that you asked is not difficult to understand .Just ignore the entire story and concentrate on this line only
“the function Z. For any positive integer N, Z(N) is the number of zeros at the end of the decimal form of number N!.”

Apparently, this problem asks you to print the number of trailing zeros the factorial of input N has.

Example::

Input=9

The factorial of 9 is 362880 .So the number of trailing zero is one ,hence answer is 1 (I have italicized and bold those zeros for convenience).

Input =20

Factorial(20)=2432902008176640000 There are four Trailing Zeros .so Answer is 4.

2 Likes