how do u find prime numbers in an array
 

hlp please

Re: how do u find prime numbers in an array
 

if you search these threads you will find several threads on this topic.

Re: how do u find prime numbers in an array
 

first write a program to catch all the prime numbers in to an array in a given or a chosen range....
and compare the elements of prime numbers with the each element of the array u want...
if one of ur array element is equal to a element of prime number array,,that means it's a prime number....

e.g.

A[4]={1,5,3,4,17}; //range is 1 to 20

primArray[10]={2,3,5,7,11,13,17,19}
now compare array 'A' with the each element of 'primArray'.

if u find hard to write a program to catch prime numbers of a given range to an array email me....

Re: how do u find prime numbers in an array
 

dude we need2 accept the numbers in an array.... so among those nos wi nid 2 find

Re: how do u find prime numbers in an array
 

Speak English please. And once you do that, you can show some effort.
http://www.daniweb.com/techtalkforum...cement8-2.html
http://www.catb.org/~esr/faqs/smart-questions.html

Re: how do u find prime numbers in an array
 

A prime number is a number that can only be evenly divided by itself and 1. Let number x equal a given element in the array. Now you can for loop from 2 to x-1 and use the modulus operator. If the resulting value is equal to 0 then it is certainly not a prime.

Good luck, LamaBot

Re: how do u find prime numbers in an array
 

I don't know how "u" does it. I do know how I'd do it.

Re: how do u find prime numbers in an array
 

/* This program is for checking a single integer*/

#include<stdio.h>

#include<stdlib.h>

main()

{

 int a,i;

 printf("\nEnter a positive integer\n");

 scanf("%d",&a);

 if(a<=0)

 {

  printf("\nInvalid input\n");

  exit(1);

 }

 for(i=2;i<=a-1;i++)

   if(a%i==0)break;

 if(i==a)printf("\n%d is prime\n",a);

 else printf("\n%d is not a prime\n",a);

}





/* This is for elements in an array*/

#include<stdio.h>

#include<stdlib.h>

#define MAX 5

main()

{

 int a[MAX],i,m;

 printf("\nEnter elements into array\n");

 for(m=0;m<=MAX-1;m++)

 {

    scanf("%d",&a[m]);

    if(a[m]>0)

    {

          for(i=2;i<=a[m]-1;i++) if(a[m]%i==0)break;

          if(i==a[m])printf("\n%d is prime\n",a[m]);

          else printf("\n%d is not a prime\n",a[m]);

    }

    else printf("\n%d is not positive\n");

 }

}