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Thread: how to fined prime number using arraylist in java

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    Default how to fined prime number using arraylist in java

    hi i am having a problem to fined a prime number between 1 to 1000


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    Default Re: how to fined prime number using arraylist in java

    Can you explain what problems you are having? Post the code you are having problems with.
    What does using an arraylist have to do with the problem?
    If you don't understand my answer, don't ignore it, ask a question.

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    Default Re: how to fined prime number using arraylist in java

    Implement the sieve of Erathostenes: a method for computing prime numbers, known to the ancient Greeks. This method will compute all prime numbers up to n. For your implementation, choose an n of 1000. Here is how you do it:

    First insert all numbers from 2 to n into a set.
    Erase all multiples of 2 (except 2); that is, 4, 6, 8, 10, 12...n
    Erase all multiples of 3: that is, 6, 9, 10, 12....n
    Repeat for all multiples up to the square root of n.
    Print the numbers remaining in the set -- these are the prime numbers
    You'll want to look up the methods on Set in the javadoc. Think carefully of what type of Set you will use -- is a TreeSet or a HashSet more appropriate?

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    Super Moderator Norm's Avatar
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    Default Re: how to fined prime number using arraylist in java

    What have you tried?
    If you don't understand my answer, don't ignore it, ask a question.

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