C plus plus code that determine prime number?

Answer 1

#include <iostream.h>

main()

{

int a;

cout<<"enter a number : ";

cin>>a;

cout<<endl;

if (a%2-1)

cout<<"it is a Prime number";

else

cout<<"it is not a prime number"

return 0;

}

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output: enter a number : 30

it is a not a prime number