3. Longest Substring Without Repeating Characters
Category: /leetcodeLeetcode Link | Sliding window template
Given a string s, find the length of the longest substring without repeating characters.
Example 1:
Input: s = "abcabcbb"
Output: 3
Explanation: The answer is "abc", with the length of 3.
Solution:
- Sliding window
def lengthOfLongestSubstring(self, s: str) -> int:
if not s: return 0
window = {}
l, r = 0, 0
res = 0
while r < len(s):
ch = s[r]
window[ch] = window.get(ch, 0) + 1
r += 1
while window[ch] > 1:
l_ch = s[l]
window[l_ch] -= 1
l += 1
res = max(r - l, res)
return res
