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March 8th, 2019, 08:08 PM   #1
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Computer program for printing Prime numbers in reverse order.

https://www.rapidtables.com/math/num...e_numbers.html

I would like to write a computer program which will print prime numbers starting from 100 till 0. i.e. reverse order.

Can I get the source code written in any programming language C,C++,Java,C#, Python etc?


Thanks & Regards,
Prashant S Akerkar

Last edited by akerkarprash; March 8th, 2019 at 08:13 PM.
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March 9th, 2019, 01:04 AM   #2
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Thanks.

Output of the program should be

97,89,83,79 and so on till 3.
Or
97
89
83
79
till
3

Thanks & Regards,
Prashant S Akerkar

Last edited by akerkarprash; March 9th, 2019 at 01:04 AM. Reason: Content updates.
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March 9th, 2019, 02:19 AM   #3
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The code can calculate the primes in ascending order: 2, 3, 5, etc., storing the results, then print them in descending order.
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March 9th, 2019, 03:26 AM   #4
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Thanks.

Can I have the source code?
This could be in any programming language viz C,C++,Java,C#, Python etc

Thanks & Regards,
Prashant S Akerkar
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March 9th, 2019, 05:00 AM   #5
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Code:
#!/usr/bin/env python3

start = 100
end   = 2

#This List will hold the prime numbers.
prime_numbers = []

#Loop from 100 to 2.
for number in range(start, end-1, -1):

    #Flag
    is_prime = True

    #Loop from 2 to number-1
    for trial_number in range(2, number):

        #If at least one trial_number divide's
        #the number perfectly (the remainder is zero)
        #then this is not a prime number.
        if number % trial_number == 0:
            is_prime = False
            break

    #Check if this number has been validated as a prime number.
    #If yes, append it to the List.
    if is_prime:
        prime_numbers.append(number)


#Print the result.
for prime in prime_numbers:
    print(prime)
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March 9th, 2019, 09:10 AM   #6
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Thanks.

Is the above source code written in Python
programming language?

I would like to test by running the program for getting the desired output.

Thanks & Regards,
Prashant S Akerkar
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March 9th, 2019, 09:53 AM   #7
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Using UBasic:

for n = 99 to 3 step -1
if prmdiv(n) = n then print n
next n

Ahem!
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March 9th, 2019, 10:46 AM   #8
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Thanks.

Can we term this new series as
Reverse Prime numbers series?

Thanks & Regards,
Prashant S Akerkar
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March 9th, 2019, 10:56 AM   #9
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Quote:
Originally Posted by akerkarprash View Post
Thanks.

Can we term this new series as
Reverse Prime numbers series?

Thanks & Regards,
Prashant S Akerkar
Prashant, go play in the traffic during rush hour
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March 9th, 2019, 11:02 AM   #10
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Quote:
Originally Posted by akerkarprash View Post
Thanks.

Is the above source code written in Python
programming language?

I would like to test by running the program for getting the desired output.

Thanks & Regards,
Prashant S Akerkar
Here is the program you need. It's Python 3.

print("97,89,83,79,73,71,67,61,59,53,47,43,41,37,3 1,29,23,19,17,13,11,7,5,3,2")
Thanks from Denis and babaliaris

Last edited by Maschke; March 9th, 2019 at 11:55 AM.
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