Longest Substring Without Repeating Characters solution

Author: PDKhan

longest-substring-without-repeating-characters/PDKhan.cpp

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+class Solution {
+    public:
+        int lengthOfLongestSubstring(string s) {
+            int result = 0;
+            int start = 0;
+            unordered_map<char, int> map;
+    
+            for(int end = 0; end < s.length(); end++){
+                char ch = s[end];
+    
+                if(map.count(ch) && map[ch] >= start)
+                    start = map[ch] + 1;
+                
+                map[ch] = end;
+                result = max(result, end - start + 1);
+            }
+    
+            return result;
+        }
+    };