Computer Science Canada

Program keeps on crashing...

Author:  AsianSensation [ Wed Sep 10, 2003 9:23 pm ]
Post subject:  Program keeps on crashing...

We were suppose to make a simple program that tells if a number is prime or not, but my program keeps on crashing, the windows xp error message keeps on popping up, and I don't know what's wrong, can someone help me? btw, I'm using Dev c++

code:

#include <iostream.h>
#include <math.h>

int main ()
{
    int num;

    cout << "Please input a number between 1 - 1000, inclusive\n";
    cin >> num;
   
    for (int i = 0; i < sqrt (num); i++)
    {
        if (num % i == 0)
            {
                cout << "This number is not prime\n";
            }
    }
     
    cin.ignore (1, '\n');
    return 0;
}

Author:  Mazer [ Wed Sep 10, 2003 9:26 pm ]
Post subject: 

i haven't tried to run your program, but my guess is that it's trying to do a modulus by 0.

Author:  AsianSensation [ Wed Sep 10, 2003 9:30 pm ]
Post subject: 

OMG!!!!

Stupid Stupid Stupid.....

All those math practices.....

and I make this mistake.....

Very Shocked
Doh!
Cussing
Hit Wall

Author:  Tony [ Wed Sep 10, 2003 10:04 pm ]
Post subject: 

you got this code all wrong... the division check should start with 2 ( cuz remember - prime is divisible by 1 and itself). Though that would be wrong too since 2 itself is a prime number. And would screw up your loop if sqrt(num) <2

I remember posting a really efficient algorithm for finding prime numbers... You should search for that on forum, that might come in handy Smile

Author:  AsianSensation [ Thu Sep 11, 2003 5:16 pm ]
Post subject: 

yeah, I did that when I fixed the code

lol, I was brain dead or something, recently, I keep finding myself in situations that I shouldn't be in...

for example, in my data management class, I was doing permutations, and I thought P(n, r) was n! / r!... I'm making sooo many simple :newbie: mistakes....


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