optimize python algorithm function - find out what elements are added and deleted in second list

basically, I need to compare two lists. I need to know what elements are added and deleted. Here is my code but it's running slow. I would like to have "high speed" version function instead of this. import itertools def compareQueues2(prev:list, curr:list): common_max_length = min(len(prev), len(curr)) m1=0 for pi in prev: for ci in curr: if pi == ci: m1+=1 break notfound = True prev_same = [] curr_same = [] common_max_length=min(common_max_length, m1) for n in range(common_max_length, 0, -1): # print(n) if notfound: for p_it in [login to view URL](range(len(prev)), n): # print (p_it) if notfound: for c_it in [login to view URL](range(len(curr)), n): s = sum([prev[p_it[i]] == curr[c_it[i]] for i in range(n)]) if s == n: #print("{} matches {}".format(p_it, c_it)) prev_same = p_it curr_same = c_it notfound = False break deleted = [i for i in range(len(prev)) if i not in prev_same] added = [i for i in range(len(curr)) if i not in curr_same] return prev_same, curr_same, deleted, added --------------------- compareQueues2(['ab', 'will del', 'gh', 'cc'], ['ab', 'gh','added', 'cc']) sample result: ((0, 2, 3), (0, 1, 3), [1], [2])