Member Avatar for Madmark88

i have recently started to learn c programming and im trying to improve my skill.i have some question about perfect numbers i searched forum but results were about C++.

question is this code finds perfect numbers between 1 to 1000000. but its not working after 8128 which is perfect number.

#include<stdio.h>
#include<conio.h>
int main (void)
{
int i,j,sum;

for(i=1;i<=1000000;i++)
{
j=1;
sum=0;
while(j<i)
{
if(i%j==0)
sum=sum+j;
j++;
}
if(sum==i)
printf("%d\n",i);
}
getch();
}
Edited by Madmark88 because: n/a
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Member Avatar for gerard4143

It could be 'appearing' to hang because the algorithm is very inefficient and its taking a long time to calculate the bigger perfect numbers. Let it run for a few hours.

Edited by gerard4143 because: n/a
Member Avatar for Banfa

Perfect numbers are few and far between the next perfect number after 8128 is 33550336 which is rather greater than 1000000 so your program can not find it.

It would appear that your program may be working.

Member Avatar for Madmark88

Thanks for helping.

Edited by Madmark88 because: n/a
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