Project Euler problem #12

#ifndef PROBLEM12_H
#define PROBLEM12_H

#include <cstdio>
#include <vector>
#include "math.h"
using namespace std;

vector<int> getfactors(int n) {
    vector<int> result;
    int end = int(sqrt(n));
    for (int i = 1; i < end; ++i) {
        if (n % i == 0) {
            result.push_back(i);
            result.push_back(n / i);
        }
    }
    if (n % end == 0) {
        result.push_back(n / end);
    }
    return result;
}

void run() {
    int nfactors_mintarget = 500;
    int nfactors = 0;
    int i = 0;
    int curtrinum = 0;
    while (nfactors < nfactors_mintarget) {
        i++;
        curtrinum += i;
        vector<int> factors = getfactors(curtrinum);
        nfactors = factors.size();
    }
    printf("The triangle number 1 + 2 + ... + %u = %u has %u factors.\n", i, curtrinum, nfactors);
}

#endif // PROBLEM12_H