Create missing-element-in-sorted-array.py

Author: kamyu104

Python/missing-element-in-sorted-array.py

@@ -0,0 +1,25 @@
+# Time:  O(logn)
+# Space: O(1)
+
+class Solution(object):
+    def missingElement(self, nums, k):
+        """
+        :type nums: List[int]
+        :type k: int
+        :rtype: int
+        """
+        def missing_count(nums, x):
+            return (nums[x]-nums[0]+1)-(x-0+1)
+
+        def check(nums, x, k):
+            return k <= missing_count(nums, x)
+
+        left, right = 0, len(nums)-1
+        while left <= right:
+            mid = left + (right-left)//2
+            if check(nums, mid, k):
+                right = mid-1
+            else:
+                left = mid+1
+        assert(not check(nums, right, k))
+        return nums[right] + (k-missing_count(nums, right))