Find missing number problem added

findMissing.py

@@ -0,0 +1,32 @@
+# Find missing number in a 
+
+# Time Complexity : O(log n)
+# Space Complexity : O(1)
+# Any problem you faced while coding this : no
+
+class Solution:
+
+    def findMissing(self, nums):
+        low, high = 0, len(nums) - 1
+
+        while low <= high:
+            mid = (low + high) // 2
+
+            # exit condition
+            if nums[mid] - nums[mid - 1] == 2:
+                return nums[mid] - 1
+
+            # decide which half to eliminate
+            if (nums[mid] - nums[low]) > (mid - low): #element is missing in left part of the array
+                high = mid - 1
+            else: #element is missing in right part of the array
+                low = mid + 1
+
+        return -1
+
+s = Solution()
+result = s.findMissing([2,3,4,5,7,8])
+result = s.findMissing([2,3,4,5,6,8])
+result = s.findMissing([2,4,5,6,7,8])
+result = s.findMissing([1,3])
+print(result)