% Perform heap sorting algorithms.

% 22 October 2021.

% Matlab program for implementation of Heap Sort.

% Written by Orhan Ozan Yildiz.

function unsorted_variables = HeapSort(unsorted_variables, app, ~)

global projectspeed

pause('on')

function unsorted_variables = shiftDown(unsorted_variables,root,theEnd)

while (root * 2) <= theEnd

child = root * 2;

if (child + 1 <= theEnd) && (unsorted_variables(child) < unsorted_variables(child+1))

child = child + 1;

end

if unsorted_variables(root) < unsorted_variables(child)

% Swap.

unsorted_variables([root child]) = unsorted_variables([child root]);

root = child;

pause(projectspeed)

b = bar(app.UIAxesVisualisation,unsorted_variables,'FaceColor','flat','EdgeColor',[0 1 0],'LineWidth',1.5);

b.CData(root,:) = [1 0 0];

b.CData(child,:) = [1 0 0];

text(app.UIAxesVisualisation,1:length(unsorted_variables),unsorted_variables,num2str(unsorted_variables'),...

'HorizontalAlignment','center','VerticalAlignment','baseline','Color','r','FontWeight','bold')

drawnow update

else

return

end

end %while

end %siftDown

count = numel(unsorted_variables);

% Because heapify is called once in pseudo-code, it is inline here.

start = floor(count/2);

while start >= 1

unsorted_variables = shiftDown(unsorted_variables, start, count);

start = start - 1;

end

%End Heapify.

while count > 1

pause(projectspeed)

unsorted_variables([count 1]) = unsorted_variables([1 count]); %Swap

count = count - 1;

unsorted_variables = shiftDown(unsorted_variables,1,count);

b = bar(app.UIAxesVisualisation,unsorted_variables,'FaceColor','flat','EdgeColor',[0 1 0],'LineWidth',1.5);

b.CData(count,:)=[1 0 0];

text(app.UIAxesVisualisation,1:length(unsorted_variables),unsorted_variables,num2str(unsorted_variables'),...

'HorizontalAlignment','center','VerticalAlignment','baseline','Color','r','FontWeight','bold')

drawnow update

end

end