feat(ml): 136.single-number.md (#407)

添加C、Java代码支持

Author: ztianming

problems/136.single-number.md

@@ -40,7 +40,7 @@ Your algorithm should have a linear runtime complexity. Could you implement it w
 
 ## 代码
 
-* 语言支持：JS，C++，Python
+* 语言支持：JS，C，C++，Java，Python
 
 JavaScrip Code：
 ```js
@@ -93,7 +93,20 @@ var singleNumber = function(nums) {
   return ret;
 };
 ```
-C++：
+C Code：
+```C
+int singleNumber(int* nums, int numsSize){
+    int res=0;
+    for(int i=0;i<numsSize;i++)
+    {
+        res ^= nums[i];
+    }
+    
+    return res;
+}
+```
+
+C++ Code：
 ```C++
 class Solution {
 public:
@@ -113,6 +126,21 @@ public:
 };
 ```
 
+Java Code：
+```java
+class Solution {
+    public int singleNumber(int[] nums) {
+        int res = 0;
+        for(int n:nums)
+        {
+            // 异或
+            res ^= n;
+        }
+        return res;
+    }
+}
+```
+
 Python Code:
 
 ```python