# Recursive merge sort code to sort in ascending order

def mergeSort(myList):
    # print "Start of mergeSort", myList
    if len(myList)>1:
        middle = len(myList)/2
        leftHalf = myList[:middle]
        rightHalf = myList[middle:]

        mergeSort(leftHalf)
        mergeSort(rightHalf)
        merge(myList, leftHalf, rightHalf)
    # print "End of mergeSort", myList

def merge(sortedList, leftHalf, rightHalf):
    # both the leftHalf and rightHalf lists are sorted
    left = 0
    right = 0
    sortedIndex = 0
    # loop until one list runs out
    while left < len(leftHalf) and right < len(rightHalf):
        if leftHalf[left] > rightHalf[right]:
            sortedList[sortedIndex] = rightHalf[right]
            right += 1
        else:
            sortedList[sortedIndex] = leftHalf[left]
            left += 1

        sortedIndex += 1

    # copy the remaining items in the leftHalf
    while left < len(leftHalf):
        sortedList[sortedIndex] = leftHalf[left]
        left += 1

    # copy the remaining items in the rightHalf
    while right < len(rightHalf):
        sortedList[sortedIndex] = rightHalf[right]
        right += 1