NGM2 - Another Game With Numbers
Little Chikoo likes to play with numbers. Often he plays the following game:
- He chooses a number N and a set of positive integers.
- He writes down all the numbers from 1 to N.
- He chooses the first number (say x) from the set and cancels out all the multiples of x from 1 to N, including x.
- He repeats step 3 for all the numbers from the set.
One day Little Chikoo was in a mood to play pranks. So his brother asked him to play the game with a certain challenge. He made the game a little harder and asked him to find out the number of integers which aren't cancelled after he completes step 4. If he does that then Little Chikoo gets to play on his brother's Nintendo for one full day. Now Little Chikoo is in a hurry and wants to finish the job as soon as possible. He has asked for your help.
Input
The first line of the input contains N and K. (N <= 10^9, K <= 15)
Then K numbers follow all in a single line. All numbers are <= 100.
Output
The output file must contain the number of integers that aren't cancelled after he finishes step 4 of the game.
Example
Input: 10 3 2 4 5 Output: 4
(The numbers 1, 3, 7 and 9 weren't cancelled).
hide comments
shashank4844:
2024-06-03 03:55:41
Accepted in first go . Try to take long (for java users) and long long ( for cpp. users) for lcm and inputs . Avoid recurssion for generating subsets . Try to solve using bitmasking and principle of inclusion and exclusion .
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hit7sh:
2022-12-03 15:30:33
consider the case which contains big distinct primes < 1e9, it will make the lcm to go huge... it wont even fit into 64 bit long, so handle it seperately, dont let the lcm grow too big. |
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omar622:
2020-12-01 23:49:56
recursive inclusion exclusion get WA in test 25.
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coolboy7:
2020-10-05 15:00:29
ac at first go |
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ak2783934:
2020-06-07 13:47:27
mine giving wrong answer after 23rd test case don't know what to do |
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ambuj2512:
2020-05-22 01:25:44
lcm(a,b)=(a*b)/gcd(a,b)
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s_hertelli:
2020-04-07 22:15:34
if you get a tle after test 23 you may want to check the gcd function
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abhinav_jain02:
2019-05-23 17:23:03
@Alexander
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Alexander:
2019-04-09 09:09:42
I have WA in 25+ test.
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linkret:
2019-03-31 15:04:30
no |
Added by: | Paranoid Android |
Date: | 2010-03-09 |
Time limit: | 1s |
Source limit: | 50000B |
Memory limit: | 1536MB |
Cluster: | Cube (Intel G860) |
Languages: | All except: NODEJS OBJC PERL6 VB.NET |
Resource: | - |