Question

Write a C program to check whether given number is prime or not by performing following steps:

1. Define an integer variable as given_number.  
2. Use the C function scanf to read the integer variable given_number.
3. Use the conditional statement to find out given_number is prime or not prime.
4. Print the final output as The number is prime or The number is not prime.

Compile and test the program on CS Linux systems

Answer 1

#include <stdio.h>

int is_prime(int n) {
    int i;
    for (i = 2; i < n; ++i) {
        if (n % i == 0) {
            return 0;
        }
    }
    return n > 1;
}

int main() {
    int given_number;
    printf("Enter a number: ");
    scanf("%d", &given_number);
    if (is_prime(given_number)) {
        printf("%d is a prime number\n", given_number);
    } else {
        printf("%d is not a prime number\n", given_number);
    }
    return 0;
}