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Author: assassint2017

Longest Substring Without Repeating Characters/Longest_Substring_Without_Repeating_Characters.cpp

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+// Runtime: 8 ms, faster than 94.43% of C++ online submissions for Longest Substring Without Repeating Characters.
+// Memory Usage: 9.9 MB, less than 74.13% of C++ online submissions for Longest Substring Without Repeating Characters.
+
+class Solution 
+{
+public:
+    int lengthOfLongestSubstring(string s) 
+    {
+        int maxLength = 0;
+        int rightPtr = s.length() - 1;
+        
+        vector<int> memo(128, -1);
+        for (int leftPtr = s.length() - 1; leftPtr >= 0; --leftPtr)
+        {
+            if (memo[s[leftPtr]] != -1 && memo[s[leftPtr]] <= rightPtr)
+                rightPtr = memo[s[leftPtr]] - 1;
+            memo[s[leftPtr]] = leftPtr;
+            maxLength = max(maxLength, rightPtr - leftPtr + 1);
+        }
+        
+        return maxLength;
+    }
+};