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# how to read an array of 10 numbers and print the prime numbers?

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## how to read an array of 10 numbers and print the prime numbers?

(OP)
this is what i wrote
could someone tell me where is my mistake?
can i use here flag at all?

#include <stdio.h>

void main ()
{
int arr[10], i, j, flag;

for (i=0;i<10;i++)

scanf ("%d", &arr[i]);

for (i=0;i<10;i++)
{
flag=1;

for (j=2;j<=(arr[i]/2); j++)
{
if (arr[i]%j==0)
{
flag=0;
break;

}
}
}

for (i=0;i<10;i++)
{
if (flag=1)

printf ("%d", arr[i]);
}
}

### RE: how to read an array of 10 numbers and print the prime numbers?

Hi

Use equality check instead of setting value :

#### CODE

if (flag==1)
Then is a conceptual mistake : you use a single variable to hold the status of all checked numbers. Of course, if the last checked one was prime, will say all were.

Either make the flag an array

#### CODE

#include <stdio.h>

int main ()
{
int arr[10], i, j, flag[10];

for (i=0;i<10;i++) scanf("%d", &arr[i]);

for (i=0;i<10;i++) {
flag[i]=1;

for (j=2;j<=(arr[i]/2); j++) {
if (arr[i]%j==0) {
flag[i]=0;
break;
}
}
}

for (i=0;i<10;i++) {
if (flag[i]) printf("%d", arr[i]);
}
}
or print the results before ending the second outer loop.

#### CODE

#include <stdio.h>

int main ()
{
int arr[10], i, j, flag;

for (i=0;i<10;i++) scanf("%d", &arr[i]);

for (i=0;i<10;i++) {
flag=1;

for (j=2;j<=(arr[i]/2); j++) {
if (arr[i]%j==0) {
flag=0;
break;
}
}
if (flag) printf("%d", arr[i]);
}
}

Feherke.
http://rootshell.be/~feherke/

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