Longest Increasing subsequence

lis.cpp

#include <vector>
#include <iostream>
#include <algorithm>
#include <iterator>

template <class ForwardIterator, class Comp = std::less<>>
auto lis(ForwardIterator begin, 
        ForwardIterator end, 
        Comp comp = Comp()) {
    
        const auto length = std::distance(begin, end);
    auto maxs = std::vector<size_t>(length, 1);

    for(auto newBegin{begin}; newBegin != end; ++newBegin) {
        auto fromBeginToNewBegin = std::distance(begin, newBegin);
        
        for(auto beginCopy {begin}; beginCopy != newBegin; ++beginCopy) {
            auto fromBeginToBeginCopy = std::distance(begin, beginCopy);
            
            if(comp(*beginCopy, *newBegin)) {
                maxs[fromBeginToNewBegin] 
                    = std::max( maxs[fromBeginToNewBegin],
                                maxs[fromBeginToBeginCopy] + 1);
            }
        }
    }
    
    return *std::max_element(std::begin(maxs), std::end(maxs));
}

int main()
{
    auto seq = std::vector<int>{6, 2, 10, 0, 8, 4, 12, 1, 7, 3, 11, 1, 9, 5, 13};
    auto lisLen = lis(std::begin(seq), std::end(seq));
    
    std::cout << "lisLen: " << lisLen << std::endl;

    return 0;
}