| Submit | All submissions | Best solutions | Back to list |
FCDC - Factorial Modulo |
You are given 2 integers a, b. Find the number of i for which i! is divisible by a but not b. if i! is divisible by a and b, then you should not count that i.
Input
One line that contains a and b.
Output
Output the result in one line.
Example
Input: 2 3 Output: 1
Constraints
1 ≤ a ≤ b ≤ 107
Explanation
2! is the only factorial which is divisible by 2 and not divisible by 3.
| Added by: | Ruhan Habib |
| Date: | 2015-11-05 |
| Time limit: | 1s |
| Source limit: | 50000B |
| Memory limit: | 1536MB |
| Cluster: | Cube (Intel G860) |
| Languages: | All except: ASM64 GOSU JS-MONKEY |
| Resource: | Own Problem |
hide comments
|
||||||||
|
2016-02-17 19:57:06 Pawe³ Ma¶luch
I've already submitted my solution and it turned out that we should consider only i! for i > 0. |
||||||||
|
2016-01-17 20:44:54 Pawe³ Ma¶luch
Should we consider i! for i >=0 or for i > 0 ? |
||||||||
|
2015-11-22 08:23:05 william
Last edit: 2015-11-22 09:00:13 |
||||||||
|
2015-11-20 20:56:58 pankaj
What will be the ans for following test cases 3 15 2 8 4 12 |
||||||||
|
2015-11-17 08:25:57 JY
Why have you kept the constraints too weak? You could have given many test cases (maybe about 10^4) OR a and b of range about 10^12, and still it could have been solved in a second . |
||||||||
|
2015-11-17 06:45:56 Ruhan Habib
A lot of submissions are trying to use too complicated methods... this can be solved easily without prime checking and stuffs. @Bhuvnesh: for the input 4 6 output should be 0. Last edit: 2015-11-17 06:52:03 |
||||||||
|
2015-11-16 19:24:53 Bhuvnesh Jain
What is the answer when a=4 and b=6? |
||||||||
|
2015-11-13 18:37:08 Prakhar Dev Gupta
@Lakshman: This problem is getting on my nerves now! I've tried so many timeS! already made 11 submissions! Should I not check for primality? If I did it on simple approach and putting your testcase, still the time taken is way too large! What else? :( Last edit: 2015-11-13 18:44:21 |
||||||||
|
2015-11-13 15:18:33 [Lakshman]
@Prakhar why you are checking for prime multiple times. Think simple, here is one test case 1234345 5465667 your code is taking more than minute , however my python code gives output in 0.05s |
||||||||
|
2015-11-13 05:57:52 Ruhan Habib
@[Lakshman]: the problem was meant to solve the way you solved it. My sample solution(the first submission) also used quite the same approach. :) |
||||||||
RSS