Many of us know about the merge subroutine from mergesort. Here, in python:
def merge(left, right):
result = []
i ,j = 0, 0
while i < len(left) and j < len(right):
if left[i] <= right[j]:
result.append(left[i])
i += 1
else:
result.append(right[j])
j += 1
Is there a way I could write merge without an additional array (without result in this case)? I have tried making use of the fact that a string $s = xy = (y^Rx^R)^R$ (where R means reverse) to no avail.
This in-place version of merge would assume that the two input subarrays are adjacent. (The first array may be from [i, j) and the second may be from [j, k) for 3 input indices i, j, and k.)
By the way, I am open to using languages other than python such as C++ or Java.
