find greatest factor of a given number

#include <stdio.h>
int caluculatefactor(int number);
int checkgreatestfactor(int num);
int main()
{
   int num,res;
   scanf("%d",&num);
   res=checkgreatestfactor(num);
   printf("%d ",res);
 
}
int caluculatefactor(int number)
{
    int i=0,maxfactor=0;
    for(i=1;i<=number/2;i++)
    {
        if(number%i==0)
        maxfactor=i;
    }
    return maxfactor;
}
int checkgreatestfactor(int num)
{
    if(num==0)
    return 0;
    else
    return (caluculatefactor(num));
}

input:

100

output:

50