Question

1) Write a function in C that takes in a single integer parameter and returns an array of factors.

The function signature should be :

int* get_factors(int number)

To make things a little easier, assume that the input (number) will never have more than 100 factors. The returned array should be null-terminated.

2) Write a main() function that asks a user for a number, calls the function above, then prints the results.

Answer 1

#include <stdio.h>
#include <stdlib.h>

int* get_factors(int number){
   int* arr = (int*)malloc(sizeof(int)*100);
   int k = 0, i;
   for(i = 1;i<=number;i++){
      if(number%i==0){
         arr[k++] = i;
      }
   }
   arr[k] = -1;
   return arr;
}


int main() {
   int n, i;
   int* res;
   
   printf("Enter number: ");
   scanf("%d",&n);
   
   res = get_factors(n);
   
   printf("Factors of %d are:\n",n);
   for(i = 0;res[i]!=-1;i++){
      printf("%d\n",res[i]);
   }
   return 0;
}