How is the time complexity of inserting an element at a specific index in an array determined?

The time complexity of inserting an element into an array at a specific index is usually O(n), where n is the number of elements in the array. This is because, after insertion, all elements to the right of the index need to be shifted to make space for the new element. For example, inserting at the beginning of the array requires shifting all elements, which takes time proportional to the size of the array. Inserting at the end (if there is free space) can be O(1). In Swift, arrays are implemented as dynamic arrays, so inserting in the middle requires shifting elements, which determines the time complexity.