Cody Problem 38. Return a list sorted by number of occurrences
1 view (last 30 days)
Show older comments
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.
0 Comments
Accepted Answer
David Hill
on 5 Apr 2021
Edited: David Hill
on 5 Apr 2021
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.
More Answers (1)
Abhinav
on 26 Apr 2023
Edited: Rik
on 26 Apr 2023
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
0 Comments
See Also
Categories
Find more on Matrix Indexing in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!