Among the options listed, the algorithm that runs in constant time is:
accessing an element of an array
This operation has a time complexity of O(1) because it retrieves an element at a specific index directly without needing to iterate through the array.
The other operations have different time complexities:
- Traversing an array has a time complexity of O(n), where n is the number of elements in the array, as it requires accessing each element.
- Binary search on a sorted array has a time complexity of O(log n), since it repeatedly divides the search interval in half.
- Sorting an array typically has a time complexity of O(n log n) or worse, depending on the sorting algorithm used.
So, the only constant time operation is accessing an element of an array.