Create 287-Find-The-Duplicate-Number.py

Author: neetcode-gh

287-Find-The-Duplicate-Number.py

@@ -0,0 +1,15 @@
+class Solution:
+    def findDuplicate(self, nums: List[int]) -> int:
+        slow, fast = 0, 0
+        while True:
+            slow = nums[slow]
+            fast = nums[nums[fast]]
+            if slow == fast:
+                break
+        
+        slow2 = 0
+        while True:
+            slow = nums[slow]
+            slow2 = nums[slow2]
+            if slow == slow2:
+                return slow