#include <iostream>
#include <vector>
#include <ctime>

void get_sum_div(int min, int max, std::vector<std::pair<int,int>>& v)
{
    const int size = max - min;
    v.resize(size);
    int count = 0;
    for(int index = 0; index < size; index++)
    {
        int sum = 1;
        int n = min + index;
        int divmax = n / 2;
        for(int i = 2; i <= divmax; i++)
        {
            if(!(n % i))
            {
                sum += i;
            }
        }
        if(sum >= min)
        {
            v[count] = std::pair<int,int>(n, sum);
            count++;
        }
    }
    v.resize(count + 1);
}

int main()
{
    time_t begin = time(0);
    const int min = 1000001;
    const int max = 1500000;

    std::vector<std::pair<int,int>> v;
    get_sum_div(min, max, v);
    time_t done = time(0);
    std::cout << "get_sum_div() done in " << done - begin << " s." << std::endl;

    std::vector<std::pair<int,int>>::const_iterator end = v.end();
    std::vector<std::pair<int,int>>::iterator i1;
    std::vector<std::pair<int,int>>::iterator i2;

    for(i1 = v.begin(); i1 != end; ++i1)
    {
        for(i2 = i1 + 1; i2 != end; ++i2)
        {
            if((i1->first == i2->second) && (i1->second == i2->first))
            {
                time_t found = time(0);
                std::cout << i1->first << " " << i2->first
                    << " found in " << found - begin << " s." << std::endl;
            }
        }
    }
    return 0;
}