Review my solution to Contest Code:LRNDSA01, Problem Code:FCTRL

Problem statement: https://www.codechef.com/LRNDSA01/problems/FCTRL
Solution: https://www.codechef.com/viewsolution/34721362
Logic: n! = n/5 + n/25 + n/125 … where n is the integer for which we are calculating the number of trailing zeros.
Status: Wrong answer

I would like to know where I went wrong.

Code:
num_list = []
T = int(input())
for x in range(T):

num_list.append(int(input().strip()))

def Z(N):
    num_zeros = 0
    i = 1
    for i in range(i,N):
        if 5**i < N:
            num_zeros += N//(5**i)
        else:
            break
    print(num_zeros)

for N in num_list:
if N in range( 1,1000000000):

Z(N)

else:
print("enter number in the range [1,1000000000]")

Please show your code. I can’t see the solution.

Try n = 5

Change 5 ** i < N to 5 ** i <= N.

I did but it still gives wrong answer

Also, if you’ve added "enter number in the range [1,1000000000]" to your actual code, you’re not supposed to do that. The tests are pre-determined. Any extra output like this will give you WA.

I think you misinterpreted what I said, can you post what you’ve actually changed?

What i meant was, try n = 5 as a test case and you’ll get it wrong

1 Like

Oh! I removed that and it worked. Thank you so much @therealnishuz and @galencolin

Do you know why that worked?

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Yeah, I had missed the edge case (<=5). It is important to pay attention to all the edge cases. I recently started coding practice on CodeChef and I am trying to get used to them.

No, it’s not just that. Python’s range is inclusive of the first argument but exclusive for the second one. So your program would think 10^9 is invalid input.

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Oh! Right. Thank you for explaining that.