feat: longest-substring-without-repeating-characters

Author: junbinding

dp.longest-substring-without-repeating-characters.py

@@ -0,0 +1,41 @@
+class Solution:
+    """
+    3. 无重复字符的最长子串
+    https://leetcode-cn.com/problems/longest-substring-without-repeating-characters/
+    给定一个字符串，请你找出其中不含有重复字符的 最长子串 的长度。
+    """
+    def lengthOfLongestSubstring(self, s: str):
+        n = len(s)
+        if n <= 1:
+            return n
+
+        left = 0
+        # 记录集合
+        lookup = set()
+        # 最大宽度
+        max_len = 0
+        # 目前宽度
+        cur_len = 0
+        for i in range(n):
+            cur_len += 1
+            # 如果最新元素在集合中，则必须移除掉该元素
+            while s[i] in lookup:
+                # 移除第一次出现新元素之前的元素
+                lookup.remove(s[left])
+                left += 1
+                cur_len -= 1
+
+            if cur_len > max_len:
+                max_len = cur_len
+            lookup.add(s[i])
+        return max_len
+
+so = Solution()
+# 3
+print(so.lengthOfLongestSubstring('abcabcbb'))
+# 1
+print(so.lengthOfLongestSubstring('bbbbb'))
+# 3
+print(so.lengthOfLongestSubstring('pwwkew'))
+# 0
+print(so.lengthOfLongestSubstring(''))