RosettaCodeData/Task/Quickselect-algorithm/Ring/quickselect-algorithm.ring

aList = [9, 8, 7, 6, 5, 0, 1, 2, 3, 4]
see partition(aList, 9, 4, 2) + nl

func partition list, left, right, pivotIndex
       pivotValue = list[pivotIndex]
       temp = list[pivotIndex]
       list[pivotIndex] = list[right]
       list[right]  = temp
       storeIndex = left
       for i = left to right-1
            if list[i] < pivotValue
               temp = list[storeIndex]
               list[storeIndex] = list[i]
               list[i] = temp
               storeIndex++ ok
            temp = list[right]
            list[right] = list[storeIndex]
            list[storeIndex] = temp
       next
       return storeIndex