a program in c to find whether a number is prime or not without using any loop ?
Answers
int check(int n, int i)
{
if (i == 1)
{
return 1;
}
else
{
if (n % i == 0)
return 0;
else
return check(n, i - 1);
}
}
int main()
{
int n, val;
printf("Enter number: ");
scanf("%d", &n);
val = check(n, n/ 2);
if (val == 1)
{
printf("%d is a prime number\n", n);
}
else
{
printf("%d is not a prime number\n", n);
}
return 0;
}
******it's recursive function*****
// C program to check if a
// number is prime
int main()
{
int n, i, flag = 1;
// Ask user for input
printf("Enter a number: \n");
// Store input number in a variable
scanf("%d", &n);
// Iterate from 2 to n/2
for (i = 2; i <= sqrt(n) / 2; i++) {
// If n is divisible by any number between
// 2 and n/2, it is not prime
if (n % i == 0) {
flag = 0;
break;
}
}
if (flag == 1) {
printf("%d is a prime number", n);
}
else {
printf("%d is not a prime number", n);
}
return 0;
}