Update

Author: fibers

.gitignore

@@ -4,3 +4,4 @@
 .mvn/*
 target
 *.class
+*.iml

src/main/java/com/fibers/algorithm/leetcode/_003/Solution.java

@@ -1,4 +1,21 @@
 package com.fibers.algorithm.leetcode._003;
 
+import java.util.HashMap;
+
 public class Solution {
+    public int lengthOfLongestSubstring(String s) {
+        if (s.length() == 0) {
+            return 0;
+        }
+        HashMap<Character, Integer> map = new HashMap<>();
+        int max = 0;
+        for (int i = 0, j = 0; i < s.length(); ++i) {
+            if (map.containsKey(s.charAt(i))) {
+                j = Math.max(j, map.get(s.charAt(i)) + 1);
+            }
+            map.put(s.charAt(i), i);
+            max = Math.max(max, i - j + 1);
+        }
+        return max;
+    }
 }