% Markov proba

A = [0.2 0.6 0.2; 0.3 0 0.7; 0.5 0 0.5];

randomWalk = zeros(1, 1000);
randomWalk(1) = 2;
x = [1 2 3];

for i = 2 : 1000
    lastState = randomWalk(i-1);
    r = rand;
    if (lastState == 1)
        if (r < 0.2)
            randomWalk(i) = 1;
        elseif (r < 0.8)
            randomWalk(i) = 2;
        else
            randomWalk(i) = 3;
        end
    elseif (lastState == 2)
        if (r < 0.3)
            randomWalk(i) = 1;
        else
            randomWalk(i) = 3;
        end
    elseif (lastState == 3)
        if (r < 0.5)
            randomWalk(i) = 1;
        else
            randomWalk(i) = 3;
        end
    end
    numHamburger = numel(find(randomWalk==1));
    percentHamburger = (numHamburger / i) * 100;
    numPizza = numel(find(randomWalk==2));
    percentPizza = (numPizza / i) * 100;
    numHotdog = numel(find(randomWalk==3));
    percentHotdog = (numHotdog / i) * 100;
    y1 = [numHamburger numPizza numHotdog]; 
    y2 = [percentHamburger percentPizza percentHotdog];
    xticks = ([1 2 3]);
    xticklabels = ({'A', 'B', 'C'});
    subplot(1,2,1), bar(x,y1)
    title('Numbers'), xlabel(i)
    axis([0.5 3.5 0 500])
    text(x(1),y1(1),num2str(numHamburger, '%0.0f'), ...
        'HorizontalAlignment','center', 'VerticalAlignment','bottom')
    text(x(2),y1(2),num2str(numPizza, '%0.0f'), ...
        'HorizontalAlignment','center', 'VerticalAlignment','bottom')
    text(x(3),y1(3),num2str(numHotdog, '%0.0f'), ...
        'HorizontalAlignment','center', 'VerticalAlignment','bottom')
    
    subplot(1,2,2), bar(x,y2)
    title('Percentages'), xlabel(i)
    axis([0.5 3.5 0 100])
    text(x(1),y2(1),num2str(percentHamburger, '%0.1f'), ...
        'HorizontalAlignment','center', 'VerticalAlignment','bottom')
    text(x(2),y2(2),num2str(percentPizza, '%0.1f'), ...
        'HorizontalAlignment','center', 'VerticalAlignment','bottom')
    text(x(3),y2(3),num2str(percentHotdog, '%0.1f'), ...
        'HorizontalAlignment','center', 'VerticalAlignment','bottom')

    if rem(i,1) == 0
        drawnow
    end
end