diff --git a/Problem Solving/Find the Duplicate Number.java b/Problem Solving/Find the Duplicate Number.java
new file mode 100644
index 0000000..fc880c6
--- /dev/null
+++ b/Problem Solving/Find the Duplicate Number.java	
@@ -0,0 +1,24 @@
+/**
+ * Solution to Find the Duplicate Number at LeetCode in Java
+ *
+ * author: hellache
+ * ref: https://leetcode.com/problems/find-the-duplicate-number/
+ */
+class Solution {
+    public int findDuplicate(int[] nums) {
+        int p1=nums[0];
+        int p2=nums[0];
+        p1=nums[p1];
+        p2=nums[nums[p2]];
+        while(p1!=p2){
+            p1=nums[p1];
+            p2=nums[nums[p2]];
+        }
+        p1=nums[0];
+        while(p1!=p2){
+            p1=nums[p1];
+            p2=nums[p2];
+        }
+        return p1;
+    }
+}