You can use a map data structure. This greatly reduces processing time as it avoids the need to compare each file with every other file as is explained below:
- One-time scan: The map is populated by scanning through the list of files only once. Each file’s case number is extracted and used as a key in the map. If the case number has already been encountered, the file is appended to the list associated with that case number; otherwise, a new list is created.
- Constant-time Access: Maps provide near-constant access for inserting and retrieving values based on keys. This is much faster than searching through a list or array to find if a case number is already present.
You can refer below to the given code using map:
reports = dir(fullfile(reports_folder, '*.doc'));
num_reports = length(reports);
case_regex = '\d+-\d+';
% Use a map to group files by their numeric string
file_map = containers.Map('KeyType', 'char', 'ValueType', 'any');
for i = 1:num_reports
baseFileName = reports(i).name;
case_number = regexp(baseFileName, case_regex, 'match', 'once'); % Extract case number
% Check if the case number is already in the map
if isKey(file_map, case_number)
file_map(case_number){end+1} = baseFileName;
else
file_map(case_number) = {baseFileName};
end
end
% Now iterate over each unique case number
for case_number = keys(file_map)
list_same_case = file_map(case_number{1});
end
