Given two lists, sort the first list and reorder the second list so that the elements remain in corresponding order.

To keep the correspondence between two lists while sorting the first, pair each element of the first list with its partner in the second list, sort the pairs, then separate them back. In Python:

list1 = [3, 1, 2]
list2 = ['c', 'a', 'b']
# Pair and sort
paired = sorted(zip(list1, list2), key=lambda x: x[0])
# Unzip
sorted_list1, sorted_list2 = zip(*paired)
print(list(sorted_list1))  # [1, 2, 3]
print(list(sorted_list2))  # ['a', 'b', 'c']

This runs in O(n log n) time due to the sort, and uses O(n) extra space for the paired list. The same logic applies to any language: create an array of index/value pairs, sort by the first element, then rebuild the two lists from the sorted pairs.