Question

Q2. To check and print if entered integer is prime or not. Prompt the user to enter a positive integer or 0 to exit. while negative integer entered - prompt for valid values again. If positive integer entered - check if it is prime. Write a separate function that accepts a positive integer as argument and checks and returns 1 if the integer is prime or 0 if it is not prime. Call the function from main. Accept the return value from the called function in main and check it to print whether the integer is prime or not. For input 1 - your program should print “Neither prime nor composite”. 2 is a prime.

Use c program and please write the steps required. Thanks

Answer 1

#include <stdio.h>

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

int main() {
    int n;
    while (1) {
        printf("Please input a positive integer or 0 to exit: ");
        scanf("%d", &n);
        if (n == 0) break;
        if (n < 0) {
            printf("%d is not a valid positive integer\n", n);
        } else {
            if (n == 1) {
                printf("%d is Neither prime nor composite\n", n);
            } else {
                if (is_prime(n)) {
                    printf("%d is a prime number\n", n);
                } else {
                    printf("%d is NOT a prime number\n", n);
                }
            }
        }
    }

    return 0;
}