on Jul 07 2021 Comment
#include <stdio.h>
int main() {
// Declare variables
int n, i, flag = 0;
// Prompt user for input
printf("Enter a positive integer: ");
scanf("%d", &n);
// Iterate from 2 to n/2
for (i = 2; i <= n/2; ++i) {
// Check if n is divisible by i
if (n % i == 0) {
flag = 1;
break;
}
}
// Check and display the result
if (n == 1) {
printf("1 is neither a prime nor a composite number.");
}
else {
if (flag == 0)
printf("%d is a prime number.", n);
else
printf("%d is not a prime number.", n);
}
return 0;
}