#include <stdio.h>
// determines prime
int main()
{
int num;
printf("Enter number:
>");
scanf("%d", &num);
if (isprime(num))
printf("%d is prime", num);
else
printf("%d is not a prime", num);
return 0;
}
int isprime(int num)
{
int i;
for (i=2; i < num; i++)
{
int n = num%i;
if (n == 0)
return 0;
}
return 1;
}
=====
#include <stdio.h>
// determines prime between
int main()
{
int num1,num2;
printf("Prime numbers
");
printf("Input numbers: ");
scanf("%d,%d", &num1, &num2);
printf("Prime numbers in between %d and %d: ", num1, num2);
printprimes(num1,num2);
return 0;
}
printprimes(int a, int b)
{
int i;
for (i = a; i < b; i++)
{
if (isprime(i))
printf("%d ", i);
}
}
int isprime(int num)
{
int i;
for (i=2; i < num; i++)
{
int n = num%i;
if (n == 0)
return 0;
}
return 1;
}
========
#include <stdio.h>
// fib nums w/c are also prime
int main()
{
int num1, num2;
printf("Fibonacci prime numbers
");
printf("Enter two numbers: ");
scanf("%d,%d", &num1, &num2);
printf("Fibonacci prime numbers between %d and %d are: ", num1, num2);
printfibo2(num1, num2);
return 0;
}
printfibo2(int a, int b)
{
int ctr;
int prev = 0, curr = 1;
for (ctr = 1; ctr <= b; ctr++)
{
if (ctr >= a && isprime(curr))
{
printf("%d ", curr);
}
int temp = curr;
curr = prev + curr;
prev = temp;
}
}
int isprime(int num)
{
int i;
for (i=2; i < num; i++)
{
int n = num%i;
if (n == 0)
{
return 0;
}
}
return 1;
}
