Cody Problem 38. Return a list sorted by number of occurrences

I found difficulties with the Problem 38 on Cody here is my solution:

function y = popularity(x)
[a,b]=size(x);
s=ones(a,b);
for i=1:b
    for j=1:b
        if i~=j
            if x(i)==x(j)
                s(i) = s(i) +1;
            end
        end
    end
end
[A,o]= sort(s,'descend');
 for k =1:b
     L(k)=x((o(k)));
 end
y= unique(L,'stable');
end

Unfortunately it doesn't work for the second case, can anyone help me with that!

Thanks in advance.

Answer 1

[David Hill]

Take a look at the functions, histcounts(), sort(), and unique(). By combining these functions you can answer the problem in a few lines without any loops.

[Hidd_1]

It worked Thank you!

Answer 2

[Abhinav]

function output_array = popularity(input_array)

%% First make unique array
unique_input_array = unique(input_array);

%% Create occurences - keys pair array
table_occurence = zeros(length(unique_input_array),2);
table_occurence(:,2) = unique_input_array';

for i = 1:length(unique_input_array)
    occurrence = numel(find(input_array == unique_input_array(i)));
    table_occurence(i,1) = occurrence;
end

%% Sort by occurences in descending order
sorted_table = sortrows(table_occurence,'descend');
occurences = sorted_table(:,1);
keys = sorted_table(:,2);

%% Find keys that have same occurences and store sorted keys in new array
occurences_total = unique(occurences,'stable');
output_array = [];

for j = 1:length(occurences_total)
    [row,~] = find(occurences == occurences_total(j));
    aa = sort(keys(row));
    output_array = [output_array, [aa']];
end

end