Question

Question 3 (10 marks) An integer number is said to be a perfect number if its factors, including 1 (but not the number itself), sum to the number. For example, 6 is a perfect number because its factors, except itself, are 3, 2, and 1, and 6 = 3+2+1, but 12 is not a perfect number because its factors, except itself, are 6, 4, 3, 2, and 1, but 12 # 6+4+3+2+1. First. Write a C function, called isperfect, that determines whether its integer parameter, num, is a perfect number or not by returning 1 if the number is a perfect number, and otherwise. Then, call this function in the main function that prints all the perfect numbers between 1 and 1000. Put your code inside the box on the next page.

Answer 1

Find the code for the above question below, read the comments provides in the code for better understanding. If found helpful please do upvote this.

Code

#include<stdio.h>//standard header fiel for c programs
#include<math.h>//for performing mathematical opeartions , in this program it is the square root

//method which returns 1 if the num is perfect else returns 0
int isPerfect(int num){
//declare and initialize a variable total to store sum of all factors
int total=0;
//run a loop from 1 till square root of the number
//beaucse the factors can be found using those numbers only
//this saves time and numebr of comparisons
for(int i=1;i<=sqrt(num);i++){
//if the num is divisible by i then it is one of teh factors
if(num%i==0){
//teh other factor will be num/i
//if both i and num/i are same then take only one i.e. i
if(num/i==i)
total += i;//add it to total
else{
//else add both i and num/i to the total
total += i;
total += num/i;
}
}
}
//the total now has the sum of all factors including teh numebr itself ,
//so subtract the number form the total
total -= num;
//now chekc if total is equal to the numebr if yes then it is a poerfect num
//in that case return 1
if(total == num)
return 1;
//else return 0
else
return 0;
}

//main driver code of the program
int main(){
//print a header
printf("Perfect Numbers from 1 - 1000 are :\n");
//run a loop from 1 to 1000 and make method call for each
for(int i=1;i<=1000;i++){
//call the isPerfect() method , if it returns 1 then it is a perfect num
//so show it
if(isPerfect(i)==1){
printf("%d ",i);
}
}
  
}

Output

The output shows all the perfect numbers from 1 to 1000 and as per the output only 3 such number exist.