First and Last Position

nums is sorted in non-decreasing order and may contain repeated values. Return [first, last]: the first and the last index where target appears. If it does not appear, return [-1, -1].

Examples

Example 1

Input:

first_and_last([5, 7, 7, 8, 8, 10], 8)

Output:

[3, 4]

Example 2

Input:

first_and_last([5, 7, 7, 8, 8, 10], 6)

Output:

[-1, -1]

Constraints

• 0 <= len(nums) <= 2 * 10**5
• nums is sorted in non-decreasing order.
• -10**9 <= nums[i], target <= 10**9
• The big tests count how many values your code reads from the list (the limit is stated in the failure message). Reading every value, or using in, .index, .count, min or sorted on the whole list, fails them.