ones tens hundreds for further clarification what if we wanted to determine how many thousands the number hasclearly there are nonebut often looking at number as final like we often do it is not so obvious so when asked the question how many thousands does have you should simply pad the number with zero in that locatione here it is more obvious that the key value at the thousands location is zero the last thing to identify before we actually show you simple implementation of radix sort that works on only positive integersand requires you to specify the maximum key size in the list is that we need way to isolate specific key at any one time the solution is actually very simplebut its not often you want to isolate key in number so we will spell it out clearly here key can be accessed from any integer with the following expressionkey (number keyt oaccess as simple example lets say that we want to access the tens key of the number the tens column is key and so after substitution yields key ( the next key to look at for number can be attained by multiplying the last key by ten working left to right in sequential manner the value of key is used in the following algorithm to work out the index of an array of queues to enqueue the item into algorithm radix(listmaxkeysize prelist maxkeysize > and represents the largest key size in the list postlist has been sorted queues queue[ indexof key fori to maxkeysize foreach item in list queues[getqueueindex(itemindexof key)enqueue(item end foreach list collapsequeues(queues clearqueues(queues indexof key indexof key end for return list end radix figure shows the members of queues from the algorithm described above operating on the list whose members are and the key we are interested in for each number is highlighted omitted queues in figure mean that they contain no items summary throughout this we have seen many different algorithms for sorting listssome are very efficient ( quick sort defined in ss )some are not (