solve longest substring without repeating characters

Author: sora0319

longest-substring-without-repeating-characters/sora0319.java

@@ -0,0 +1,33 @@
+class Solution {
+    public int lengthOfLongestSubstring(String s) {
+        Map<Character, Integer> characters = new HashMap<>();
+        int maxLength = 0;
+        int length = 0;
+        int start = 0;
+
+        for(int i = 0; i < s.length(); i++){
+            if(!characters.containsKey(s.charAt(i))){
+                characters.put(s.charAt(i), i);
+                length++;
+            }
+            else{
+                maxLength = Math.max(length, maxLength);
+
+                int place = characters.get(s.charAt(i));
+                if(place < start){
+                    characters.put(s.charAt(i), i);
+                    length++;
+                    continue;
+                }
+
+                length = i - place;
+                start = place + 1;
+                characters.put(s.charAt(i), i);
+            }
+        }
+        maxLength = Math.max(length, maxLength);
+
+        return maxLength;
+    }
+}
+