2 pointers

Author: Simcoderan

3.Longest Substring Without Repeating Characters/Solution.java

@@ -0,0 +1,35 @@
+class Solution {
+    public int lengthOfLongestSubstring(String s) {
+        if(s==null || s.length()==0){
+            return 0;
+        }
+        if(s.length()==1){
+            return 1;
+        }
+
+        int left=0;
+        int right=0;
+        int ans=0;
+
+        HashSet<Character> set=new HashSet<>();
+
+        while(right<s.length()){
+            //to find the value of the particular index
+            char c =  s.charAt(right);
+
+           //if the value exists in hashset or not
+            while(set.contains(c)){
+                set.remove(s.charAt(left));
+                left++;
+         }
+         set.add(c);
+         ans=Math.max(ans,right-left+1);
+         right++;
+
+
+        }
+
+        return ans;
+        
+    }
+}