[Divide and Conquer] 분할정복 - not completed!

병합정렬

def merge_sort(li, left, right):
    if(left < right):
        mid = (left + right) // 2
        merge_sort(li, left, mid)
        merge_sort(li, mid+1, right)
        merge(li, left, mid, right)

def merge(li, left, mid, right):
    k = left
    i = left
    j = left
    while i <= mid and j <= right:
        if A[i] <= A[j]: