add java solution for problem 136 & update readme

README.md

@@ -426,7 +426,7 @@ LeetCode
 |139|[Word Break](https://leetcode.com/problems/word-break/)| [C++](./algorithms/cpp/wordBreak/wordBreak.cpp)|Medium|
 |138|[Copy List with Random Pointer](https://leetcode.com/problems/copy-list-with-random-pointer/)| [C++](./algorithms/cpp/copyListWithRandomPointer/copyListWithRandomPointer.cpp), [Python](./algorithms/python/CopyListWithRandomPointer/copyRandomList.py)|Hard|
 |137|[Single Number II](https://leetcode.com/problems/single-number-ii/)| [C++](./algorithms/cpp/singleNumber/singleNumber.II.cpp), [Python](./algorithms/python/SingleNumberII/SingleNumberII.py)|Medium|
-|136|[Single Number](https://leetcode.com/problems/single-number/)| [C++](./algorithms/cpp/singleNumber/singleNumber.cpp)|Medium|
+|136|[Single Number](https://leetcode.com/problems/single-number/)| [C++](./algorithms/cpp/singleNumber/singleNumber.cpp), [Java](./algorithms/java/src/SingleNumber/SingleNumber.java)|Medium|
 |135|[Candy](https://leetcode.com/problems/candy/)| [C++](./algorithms/cpp/candy/candy.cpp)|Hard|
 |134|[Gas Station](https://leetcode.com/problems/gas-station/)| [C++](./algorithms/cpp/gasStation/gasStation.cpp)|Medium|
 |133|[Clone Graph](https://leetcode.com/problems/clone-graph/)| [C++](./algorithms/cpp/cloneGraph/cloneGraph.cpp)|Medium|

algorithms/java/src/SingleNumber/SingleNumber.java

@@ -0,0 +1,50 @@
+// Source : https://leetcode.com/problems/single-number/description/
+// Author : Anas Mak
+// Date   : 2023-01-25
+
+/**********************************************************************************
+ Given a non-empty array of integers nums, every element appears twice except for one.
+ Find that single one.
+
+ You must implement a solution with a linear runtime complexity and
+ use only constant extra space.
+
+ Here are few examples.
+ Example 1:
+
+ Input: nums = [2,2,1]
+ Output: 1
+ Example 2:
+
+ Input: nums = [4,1,2,1,2]
+ Output: 4
+ Example 3:
+
+ Input: nums = [1]
+ Output: 1
+
+ * 
+ **********************************************************************************/
+package Solution;
+
+ class Solution {
+    public int singleNumber(int[] nums) {
+
+        Set <Integer> single = new HashSet <> ();
+        for(int i : nums){
+            if(!single.contains(i)){
+                single.add(i);
+            }
+
+            else{
+                single.remove(i);
+            }
+        }
+
+        for(int result : single){
+            return result;
+        }
+
+        return -1;
+    }   
+}

algorithms/java/src/SingleNumber/SingleNumberTest.java

@@ -0,0 +1,21 @@
+package Solution;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * Test for 58. Length of Last Word
+ */
+public class TestLengthOfLastWord {
+	@Test
+	public void test() {
+		Solution solution = new Solution();
+		int[] array1 = [2,2,1];
+		Assert.assertTrue(solution.SingleNumber(array1) == 1);
+		int[] array2 = [4,1,2,1,2];
+		Assert.assertTrue(solution.SingleNumber(array2) == 4);
+        int[] array3 = [1];
+		Assert.assertTrue(solution.SingleNumber(array3) == 1);
+
+	}
+}