CODEWITHSUNDEEP
c++prime-factoring
JohnCena7070
JohnCena7070

Reputation: 23

Prime factorization

I have here a simple algorithm for factorizing. 

void primeFactor(int number){
    if (number == 1)return;

    int x = 2;
    while (number%x != 0)x++;

    cout << x << endl;
    primeFactor(number / x);
}

It works fine for small numbers, but when ever I enter a big number like 809800987876, I get a -1 after about 3 factors.

So here's sample output for 809800987876.

> 2 2 486957767
> -1

How can I fix this?

Upvotes: 2

Views: 194

Answers (1)

NathanOliver
NathanOliver

Reputation: 180415

You are overflowing the int. On a typical system the maximum value of an int is 2147483647. 809800987876 is larger than that so it overflows. You can use a long long which has at least a max of 9223372036854775807.

Upvotes: 2

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