feat(ml): $3.longest-substring-without-repeating-characters.md

problems/3.longest-substring-without-repeating-characters.md

@@ -66,7 +66,65 @@ https://leetcode-cn.com/problems/longest-substring-without-repeating-characters/
 
 ## 代码
 
-代码支持：Python3
+代码支持：C++，Java，Python3
+
+
+C++ Code:
+
+```c++
+class Solution {
+public:
+    int lengthOfLongestSubstring(string s) {
+
+        int max_len = 0, start = 0;
+        int n = s.length();
+        // 
+        map<char, int> mp;
+
+        for(int i=0;i<n;i++)
+        {
+            char alpha = s[i];
+            if(mp.count(alpha))
+            {
+                start = max(start, mp[alpha]+1);
+            }
+            max_len = max(max_len, i-start+1);
+            // 字符位置
+            mp[alpha] = i;
+        }
+
+        return max_len;
+    }
+};
+```
+
+
+Java Code:
+
+```java
+class Solution {
+    public int lengthOfLongestSubstring(String s) {
+        int max_len = 0, start = 0;
+        int n = s.length();
+        // 
+        Map<Character, Integer> map = new HashMap<>();
+
+        for(int i=0;i<n;i++)
+        {
+            char alpha = s.charAt(i);
+            if(map.containsKey(alpha))
+            {
+                start = Math.max(start, map.get(alpha)+1);
+            }
+            max_len = Math.max(max_len, i-start+1);
+            // 字符位置
+            map.put(alpha, i);
+        }
+
+        return max_len;
+    }
+}
+```
 
 Python3 Code: