Tell: When a questions asks for "consecutive string/array" or "substring/sub-array", it could be that sliding window can work.
Usually we need to track 4 things:
[1, 2, 3, 4, 5]
^ ^
globally:
sol = global var storing final solution
p1 = starting window
p2 = window end
locally (of each iteration):
new = newly added element in window
curr_sol = local variable with solution of that window
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https://leetcode.com/problems/longest-substring-without-repeating-characters/
Tip: it can get really confusing with too many variables, so keep number of variables in check. I always get lost between window pointers.