Question

Write a C Program To Check Whether The Given Input Number Is Prime Number Or Not Using Recursion. So, The Input Is An Integer And Output Should Print Whether The Integer Is Prime Or Not. Note That You Have To Use Recursion.

Answer 1

Answer:

/*

* C Program to find whether a Number is Prime or Not using Recursion

*/

#include <stdio.h>

int primeno(int, int);

int main()

{

int num, check;

printf("Enter a number: ");

scanf("%d", &num);

check = primeno(num, num / 2);

if (check == 1)

{

printf("%d is a prime number\n", num);

}

else

{

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

}

return 0;

}

int primeno(int num, int i)

{

if (i == 1)

{

return 1;

}

else

{

if (num % i == 0)

{

return 0;

}

else

{

return primeno(num, i - 1);

}

}

}