How can you get other font-weight fonts from one regular?

Question

C++ / C#

Are there any services or programs that can be used to get several fonts from one file with the '.ttf' font, but not formats like '.eot' , 'woff' but the font weight, that is,
(font weight) & (font-weight) . If there is, please send the link ... I searched the internet, but I did not find anything useful besides font format converters.

Answer 1

If I understood correctly, it is necessary to calculate how many elements fell into the groups in total.

int main(int argc, char* argv[])
{
    long a[] = { 1, 2, 3, 2, 1, 4, 3, 3};
    std::cout << "Initial array: " << std::endl;

    for (const auto& it : a)
        std::cout << it << ' ';
    std::cout << std::endl;

    int groupCount = 0;
    int totalItemsInGroups = 0;
    int n = sizeof(a) / sizeof(a[0]);
    for (int i = 0; i < n && a[i] != 0; i++) {
        long itemsInGroup = a[i];
        int count = 0;
        for (int j = i; j < n; j++) {
            if (a[j] == itemsInGroup) {
                a[j] = 0;
                count++;
                if (count == itemsInGroup) {
                    groupCount++;
                    totalItemsInGroups += itemsInGroup;
                    count = 0;
                }
            }
        }
    }

    std::cout << "Group count: " << groupCount << std::endl
        << "Total count of grouped items: " << totalItemsInGroups;

    return 0;
}

Conclusion:

Initial array:
1 2 3 2 1 4 3 3
Group count: 4
Total count of grouped items: 7