Question

I need a piece of code in lua language that can find sequential items in an array that the number of item in the group exceeds a specific nubmer. Example:if I have the array(the numbers won’t be in the right order, randomly distributed)->( 2,5,9,10,11,21,23,15,14,12,22,13,24 ) ; there are two sequential groups (9,10,11,12,13,14,15) and (21,22,23,24 ) . I want the first group to be found if the specific number say (4) or more, or I can get the two groups if the number is (3) or less for example.
thanks

Answer 1

The logical way would seem to be to reorder the table and look for gaps in the sequences.

function table.copy(t)
    local t2 = {}
    for k,v in pairs(t) do
        t2[k] = v
    end
    return t2
end

function groups(org, cnt)
    --  Returns a table containing tables containing the groups found
    local res = {}
    local group = {}
    tbl = table.copy(org) -- Prevent reordering of Original Table
    table.sort(tbl)
    local last = nil
    for _,val in ipairs(tbl) do
        if last and last + 1 ~= val then
            if #group >= cnt then
                table.insert(res,group)
            end
            group = {}
        end
        table.insert(group,val)
        last = val
    end
    if #group >= cnt then
        table.insert(res,group)
    end
    return res
end
local org = { 2,5,9,10,11,21,23,15,14,12,22,13,24 }
local result = groups(org,3)
print('Number of Groups',#result)