No AI assistance was used in creating this solution
We know that the following information from the question:
- Numbers in the collection start at 0
- Numbers in the collection are distinct
- Numbers in the collection are consecutive
- There is only one missing number
We also know that the largest element of the array is the same as the length of the array. i.e n = array.Count
We can therefore create a new collection with elements 0 through n and use the LINQ Except method to find the missing element and use LINQ Single or LINQ First to return the result given that we know there will be only one missing element.
Since the LINQ Except method internally uses a HashSet, the time complexity of this implementation is O(n).