Question

In this example you are allowed to use from the C standard library only functions for input and output (e.g. printf(), scanf())

Complete the following functions using C programming language:

A positive integer number is said to be a perfect number if its positive factors, including 1 (but not the number itself), sum to the number. For example, 6 is a perfect number because 6=1+2+3. Complete the int Q6(intQ6_input, int perfect[])function that determines all perfect numbers smaller than or equal to some integer Q6_input(Q6_input> 1).

• You have to print using this format:

• perfect is an array that you need to add into it any perfect number you, which means at the end of this function, the perfect[] array should hold all the found perfect numbers in the range you do not need to return perfect because arrays are already passed by reference. so, modifying them will automatically reflect in the main calling function.

• The array perfect[]should hold all the perfect numbers you find.

• The function should also return the total count of the perfect numbers you found.

Note: Assume that x and y are two positive integers. Then x is a factor of y if the remainder of the division of y by x is 0. For instance, 5 is a factor of 15, but not of 36.

For example: if Q6_inputis 10 then the only perfect number you will find is 6. Accordingly, perfect[0] should be equal 6 and the function should return 1 as your count.

Answer 1

Code:

#include<stdio.h>
int Q6(int Q6_input, int *perfect)
{
   int i,j,count=0,factSum;/*Declaring variables*/
   for(i=6;i<=Q6_input;i++)
   {/*This loop iterates for 6 to Q6_input
   because 6 is the first perfect number*/
       factSum=0;/*For every iteration we make factors sum to 0*/
       for(j=1;j<i;j++)
       {
           /*This loop iterates for 1 to i-1 values*/
           if(i%j==0)
           {/*If i is divisible by j then we add it to the factsum*/
               factSum+=j;
           }  
       }
       if(factSum==i)
       {/*If factsum is equals to the i
           then we append it to the perfect array*/
           *(perfect+count)=i;
           count++;
           /*Here we increase the count*/
       }
   }
   return count;/*Here we return the count of the perfect numbers*/
}
int main()
{
   int num,i,perfect[100],count;/*Declaring variables*/
   printf("Enter a number to print perfect numbers below a given number:");
   scanf("%d",&num);/*Here we read the input from the user*/
   count=Q6(num,perfect);/*Here we call the function by passing the num and array reference*/
   if(count==0)
   {/*If count is 0 means no perfect numbers in the range*/
       printf("There are no perfect numbers in the given range");
   }
   else
   {/*IF count is greater than 0 we print the perfect numbers*/
       printf("Perfect numbers in the given range are:\n");
       for(i=0;i<count;i++)
       {
           printf("%d\n",perfect[i]);
       }
   }
  
  
}

Output:

Indentation: