Berlin

function W = solver(B)
W = zeros(0,4);
[II,JJ,AA] = find (B);
A = [II JJ AA];
Points = [A(:,1:2) A(:,1:2)];
Alfab = unique (B);
Alfab = Alfab (find(Alfab));
Score = zeros (size(Alfab));
BestScore = 0;

for ix = 1:length (Alfab)
    Value = Alfab(ix);
    findV = find (A(:,3)==Value);
    PV = A (findV, 1:2);
    Path = TheBest (PV);
    Score(ix) = size (Path,1) + sum(sum(B)) - 2*Value;
    if Score(ix) < BestScore
        W = Path;
        BestScore = Score(ix);
    end
end

return;

function Best = TheBest (PV)
    if size(PV,1) > 1
        Diffe = PV(2,:) - PV(1,:);
        Best = zeros (sum(abs(Diffe)), 4);
        for iy = 1:abs(Diffe(1))
            Best (iy, :) = [PV(1,1)+sign(Diffe(1))*iy PV(1,2)];
        end
        for iz = iy+1:size(Best,1)
            Best (iz, :) = [PV(2,1) PV(1,2)+sign(Diffe(2))*(iz-iy)];
        end
    else Best = zeros (0,4);
return;