Programming Forums - View Single Post

glimmy · Aug 30th, 2006, 9:48 PM

Its funny you should bring this up. Earlier today I made a similar program, though mine just goes through all numbers upto 1,000,000,000:

 cpp Syntax (Toggle Plain Text) 
#include <iostream>
 
using namespace std;
 
int main() {
        int ind = 0;
        int prime;
        int max;
 
        int list[10000000] = {2};
 
        for (int i = 3;i < 1000000000;i++) {
 
                prime = 1;
 
                for (int j = 0; j < ind; j++) {
                        if ((i%list[j]) == 0) {
                                prime = 0;
                                break;
                        }
                }
 
                if (prime == 1) {
                        ind++;
                        list[ind] = i;
                        cout << i << "\n";
                }
        }
        return 0;
}
#include <iostream>

using namespace std;

int main() {
        int ind = 0;
        int prime;
        int max;

        int list[10000000] = {2};

        for (int i = 3;i < 1000000000;i++) {

                prime = 1;

                for (int j = 0; j < ind; j++) {
                        if ((i%list[j]) == 0) {
                                prime = 0;
                                break;
                        }
                }

                if (prime == 1) {
                        ind++;
                        list[ind] = i;
                        cout << i << "\n";
                }
        }
        return 0;
}

I had an earlier version that brute forced every number, but I found that only using primes works much faster.

Aug 30th, 2006, 9:48 PM	#7
glimmy Programmer Join Date: May 2005 Location: Minnesota Posts: 42 Rep Power: 0	Its funny you should bring this up. Earlier today I made a similar program, though mine just goes through all numbers upto 1,000,000,000: cpp Syntax (Toggle Plain Text) #include <iostream> using namespace std; int main() { int ind = 0; int prime; int max; int list[10000000] = {2}; for (int i = 3;i < 1000000000;i++) { prime = 1; for (int j = 0; j < ind; j++) { if ((i%list[j]) == 0) { prime = 0; break; } } if (prime == 1) { ind++; list[ind] = i; cout << i << "\n"; } } return 0; } #include <iostream> using namespace std; int main() { int ind = 0; int prime; int max; int list[10000000] = {2}; for (int i = 3;i < 1000000000;i++) { prime = 1; for (int j = 0; j < ind; j++) { if ((i%list[j]) == 0) { prime = 0; break; } } if (prime == 1) { ind++; list[ind] = i; cout << i << "\n"; } } return 0; } I had an earlier version that brute forced every number, but I found that only using primes works much faster.