July 31st, 2003, 04:35 AM
hello, i'm new !
can somebody please help in c program .
the program is to make a program that will display all prime numbers.
July 31st, 2003, 08:51 AM
This should not be difficult to program if you understood what a prime number is.
First a basic of what a prime number is , if you already dont know..
prime numbers are numbers that are divisible by 1 and itself.
int main(int argc, char** argv)
int max,flag =0,i,j;
printf("\nEnter the maximum numbers u want prime for:");
printf("The prime numbers from 1 to %d are : ",max);
for(i= 1; i <= max; i++)
flag = 0;
/*Division is just for square root of the value i
sufficient to check all the possible*/
for(j =2 ; j <= sqrt(i); j++)
if(i%j == 0)
flag = 1;
if(flag == 0)
Last edited by Raghuraman; July 31st, 2003 at 08:54 AM.
July 31st, 2003, 09:06 AM
This sounds suspiciously like your homework. Since we aren't here to do your homework for you, tell us where you're having the problem and we'll see what we can do.
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July 31st, 2003, 11:57 AM
Plus, your subject title is unacceptable. You can refer to the sticky thread at the top of this forum for more information on how to post a question.
July 31st, 2003, 02:41 PM
Not only that...
But what do you mean by 'all prime numbers'? There are an infinite number of them. If you want prime numbers bigger than a value that will fit in your computer's word (probably 32 bits) you need extra libraries (or work in FORTRAN).
Try googling on "Sieve of Eratosthenes".
August 1st, 2003, 02:24 AM
sorry i forgot to add, the range is from 2 to 150 .
thank for all of you who help me
August 1st, 2003, 07:52 AM
Re: Not only that...
FORTRAN has the same limitations on range of integers it can support as C or C++ (i.e. typically 16, 32, or 64 bits on most systems).
If you want bigger integers in C, C++, or FORTRAN (specifically FORTRAN 90 or later) you are normally looking at user defined types or data structures with associated support functions.
I also assume you made a little typo and meant Sieve of Erastothenes :-)
August 1st, 2003, 11:59 AM
2-150? Wow, that's a short range.
setup list of primes
for each number in range:
if number is evenly divisible by any number in list of primes, mark as non-prime
If prime, add to list
print list of primes
Last edited by dog135; August 1st, 2003 at 12:11 PM.