Question

Can anyone offer an alternative to removing duplicates from an numeric indexed
table that will keep a record of the duplicate?, this one works but on tables of
1000 or more entries it just seems to eat the cpu that in turn gives “not responding”
in the app lua is embedded in.

   local Dupes ={}  
   local t2 = {};  
   for i,v in pairs(t1) do   
    Count = table.getn(t2)     
    t2[v] = i  
    Count1 = table.getn(t2)   
     if Count == Count1 then  
      table.insert(Dupes,v)  
     end  
   end  

Answer 1

I don’t really see the purpose of the use of getn. Just test to see if it’s already there:

local Dupes ={}  
local t2 = {};  
for i,v in pairs(t1) do
    if(t2[v] ~= nil) then
        table.insert(Dupes,v)
    end
    t2[v] = i
end