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

CodeChef-DSA-learners
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1

Problem statement: CodeChef: Practical coding for everyone
Solution: CodeChef: Practical coding for everyone
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]")

2

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

3

Try n = 5

4

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

5

I did but it still gives wrong answer

6

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.

7

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
8

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

9

Do you know why that worked?

1 Like
10

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.

11

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.

1 Like
12

Oh! Right. Thank you for explaining that.