Find the Insertion Index

You are given a sorted array that contains unique values, along with an integer target.

• If the array contains the target value, return its index.
• Otherwise, return the insertion index. This is the index where the target would be if it were inserted in order, maintaining the sorted sequence of the array.

Example 1:

Input: nums = [1, 2, 4, 5, 7, 8, 9], target = 4
Output: 2

Example 2:

Input: nums = [1, 2, 4, 5, 7, 8, 9], target = 6
Output: 4

Explanation: 6 would be inserted at index 4 to be positioned between 5 and 7: [1, 2, 4, 5, 6, 7, 8, 9].