Question

Write a program that does the following. It will ask the user to enter an integer larger than 1, and the if entered integer is not larger than 1, it keeps prompting the user. After the user enters a valid integer, the program prints all the prime factors of the integer (including the repeated factors). For example, if the entered integer is 24, the program prints:
2 2 2 3

Run your program with the test cases where the entered integers are 72 and 360360 respectively. Include your code and the screenshots of its executions in a PDF file and submit the file. Program must be in C.

Answer 1

Program:

#include <stdio.h>
#include <math.h>

void getPrimeFactors(int num) 
{ 
    // Print the number of 2s that divide the number 
    while (num%2 == 0) 
    { 
        printf("%d ", 2); 
        num = num/2; 
    } 
  
    // If the number is odd
    for (int x = 3; x <= sqrt(num); x = x+2) 
    { 
        // While x divides num, print x and divide num 
        while (num%x == 0) 
        { 
            printf("%d ", x); 
            num = num/x; 
        } 
    } 
  
    // If number is prime and greater than 2 
    if (num > 2) 
        printf ("%d ", num); 
} 

int main()
{
    int input_number;
    // Read an integer input from user
    printf("Enter an integer larger than 1 : ");
    scanf("%d", &input_number);
    // If the given number is not greater than 1 ask the user to enter number again
    while (input_number <= 1) {
        // Read input from user
        printf("Enter an integer larger than 1 : ");
        scanf("%d", &input_number);
    }
    // Method call to print prime factors of given number
    getPrimeFactors(input_number);

    return 0;
}

Output: