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Sliding Window
Question 1 of 1010% Complete
Medium
Complete the variable sliding-window for longest substring without repeating characters
Maintain a window with a map from char to last index; shrink on repeats.
def lengthOfLongestSubstring(s: str) -> int:
last = {}
left = 0
best = 0
for right, ch in enumerate(s):
if ch in last and :
return best
Need a hint?
When a repeat appears inside the window, move left just past its last occurrence.